ZFS(8) Maintenance Commands and Procedures ZFS(8)

NAME

zfs - configures ZFS file systems

SYNOPSIS

zfs [-?]
zfs create [-Pnpv] [-o property=value]... filesystem
zfs create [-Pnpsv] [-b blocksize] [-o property=value]... -V size volume
zfs destroy [-Rfnprv] filesystem|volume
zfs destroy [-Rdnprv] filesystem|volume@snap[%snap[,snap[%snap]]]...
zfs destroy filesystem|volume#bookmark
zfs snapshot [-r] [-o property=value]...
filesystem@snapname|volume@snapname...
zfs rollback [-Rfr] snapshot
zfs clone [-p] [-o property=value]... snapshot filesystem|volume
zfs promote clone-filesystem
zfs rename [-f] filesystem|volume|snapshot filesystem|volume|snapshot
zfs rename [-fp] filesystem|volume filesystem|volume
zfs rename -r snapshot snapshot
zfs list [-r|-d depth] [-Hp] [-o property[,property]...] [-s property]...
[-S property]... [-t type[,type]...] [filesystem|volume|snapshot]...
zfs remap filesystem|volume
zfs set property=value [property=value]... filesystem|volume|snapshot...
zfs get [-r|-d depth] [-Hp] [-o field[,field]...] [-s source[,source]...]
[-t type[,type]...] all | property[,property]...
filesystem|volume|snapshot|bookmark...
zfs inherit [-rS] property filesystem|volume|snapshot...
zfs upgrade
zfs upgrade -v
zfs upgrade [-r] [-V version] -a | filesystem
zfs userspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
[-t type[,type]...] filesystem|snapshot
zfs groupspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
[-t type[,type]...] filesystem|snapshot
zfs projectspace [-Hp] [-o field[,field]...] [-s field]... [-S field]...
filesystem|snapshot
zfs project [-d|-r] file|directory...
zfs project -C [-kr] file|directory...
zfs project -c [-0] [-d|-r] [-p id] file|directory...
zfs project [-p id] [-rs] file|directory...
zfs mount
zfs mount [-Olv] [-o options] -a | filesystem
zfs unmount [-f] -a | filesystem|mountpoint
zfs share -a | filesystem
zfs unshare -a | filesystem|mountpoint
zfs bookmark snapshot bookmark
zfs send [-DLPRbcehnpvw] [[-I|-i] snapshot] snapshot
zfs send [-LPcenvw] [-i snapshot|bookmark] filesystem|volume|snapshot
zfs send [-Penv] -t receive_resume_token
zfs receive [-Fhnsuv] [-o origin=snapshot] [-o property=value]
[-x property] filesystem|volume|snapshot
zfs receive [-Fhnsuv] [-d|-e] [-o origin=snapshot] [-o property=value]
[-x property] filesystem
zfs receive -A filesystem|volume
zfs allow filesystem|volume
zfs allow [-dglu] user|group[,user|group]...
perm|@setname[,perm|@setname]... filesystem|volume
zfs allow [-dl] -e|everyone perm|@setname[,perm|@setname]...
filesystem|volume
zfs allow -c perm|@setname[,perm|@setname]... filesystem|volume
zfs allow -s @setname perm|@setname[,perm|@setname]... filesystem|volume
zfs unallow [-dglru] user|group[,user|group]...
[perm|@setname[,perm|@setname]...] filesystem|volume
zfs unallow [-dlr] -e|everyone [perm|@setname[,perm|@setname]...]
filesystem|volume
zfs unallow [-r] -c [perm|@setname[,perm|@setname]...] filesystem|volume
zfs unallow [-r] -s -@setname [perm|@setname[,perm|@setname]...]
filesystem|volume
zfs hold [-r] tag snapshot...
zfs holds [-r] snapshot...
zfs release [-r] tag snapshot...
zfs diff [-FHt] snapshot snapshot|filesystem
zfs program [-jn] [-t timeout] [-m memory_limit] pool script [arg1 ...]
zfs load-key [-rn] [-L keylocation] [-a|filesystem]
zfs unload-key [-r] [-a|filesystem]
zfs change-key [-l] [-o keylocation=value] [-o keyformat=value]
[-o pbkdf2iters=value] filesystem

DESCRIPTION

The zfs command configures ZFS datasets within a ZFS storage pool, as
described in zpool(8). A dataset is identified by a unique path within the
ZFS namespace. For example:

pool/{filesystem,volume,snapshot}

where the maximum length of a dataset name is MAXNAMELEN (256 bytes) and
the maximum amount of nesting allowed in a path is 50 levels deep.

A dataset can be one of the following:

file system A ZFS dataset of type filesystem can be mounted within the
standard system namespace and behaves like other file systems.
While ZFS file systems are designed to be POSIX compliant,
known issues exist that prevent compliance in some cases.
Applications that depend on standards conformance might fail
due to non-standard behavior when checking file system free
space.

volume A logical volume exported as a raw or block device. This type
of dataset should only be used under special circumstances.
File systems are typically used in most environments.

snapshot A read-only version of a file system or volume at a given
point in time. It is specified as filesystem@name or
volume@name.

ZFS File System Hierarchy

A ZFS storage pool is a logical collection of devices that provide space
for datasets. A storage pool is also the root of the ZFS file system
hierarchy.

The root of the pool can be accessed as a file system, such as mounting and
unmounting, taking snapshots, and setting properties. The physical storage
characteristics, however, are managed by the zpool(8) command.

See zpool(8) for more information on creating and administering pools.

Snapshots

A snapshot is a read-only copy of a file system or volume. Snapshots can
be created extremely quickly, and initially consume no additional space
within the pool. As data within the active dataset changes, the snapshot
consumes more data than would otherwise be shared with the active dataset.

Snapshots can have arbitrary names. Snapshots of volumes can be cloned or
rolled back, but cannot be accessed independently.

File system snapshots can be accessed under the .zfs/snapshot directory in
the root of the file system. Snapshots are automatically mounted on demand
and may be unmounted at regular intervals. The visibility of the .zfs
directory can be controlled by the snapdir property.

Clones

A clone is a writable volume or file system whose initial contents are the
same as another dataset. As with snapshots, creating a clone is nearly
instantaneous, and initially consumes no additional space.

Clones can only be created from a snapshot. When a snapshot is cloned, it
creates an implicit dependency between the parent and child. Even though
the clone is created somewhere else in the dataset hierarchy, the original
snapshot cannot be destroyed as long as a clone exists. The origin
property exposes this dependency, and the destroy command lists any such
dependencies, if they exist.

The clone parent-child dependency relationship can be reversed by using the
promote subcommand. This causes the "origin" file system to become a clone
of the specified file system, which makes it possible to destroy the file
system that the clone was created from.

Mount Points

Creating a ZFS file system is a simple operation, so the number of file
systems per system is likely to be numerous. To cope with this, ZFS
automatically manages mounting and unmounting file systems without the need
to edit the /etc/vfstab file. All automatically managed file systems are
mounted by ZFS at boot time.

By default, file systems are mounted under /path, where path is the name of
the file system in the ZFS namespace. Directories are created and
destroyed as needed.

A file system can also have a mount point set in the mountpoint property.
This directory is created as needed, and ZFS automatically mounts the file
system when the zfs mount -a command is invoked (without editing
/etc/vfstab). The mountpoint property can be inherited, so if pool/home
has a mount point of /export/stuff, then pool/home/user automatically
inherits a mount point of /export/stuff/user.

A file system mountpoint property of none prevents the file system from
being mounted.

If needed, ZFS file systems can also be managed with traditional tools
(mount, umount, /etc/vfstab). If a file system's mount point is set to
legacy, ZFS makes no attempt to manage the file system, and the
administrator is responsible for mounting and unmounting the file system.

Zones

A ZFS file system can be added to a non-global zone by using the zonecfg
add fs subcommand. A ZFS file system that is added to a non-global zone
must have its mountpoint property set to legacy.

The physical properties of an added file system are controlled by the
global administrator. However, the zone administrator can create, modify,
or destroy files within the added file system, depending on how the file
system is mounted.

A dataset can also be delegated to a non-global zone by using the zonecfg
add dataset subcommand. You cannot delegate a dataset to one zone and the
children of the same dataset to another zone. The zone administrator can
change properties of the dataset or any of its children. However, the
quota, filesystem_limit and snapshot_limit properties of the delegated
dataset can be modified only by the global administrator.

A ZFS volume can be added as a device to a non-global zone by using the
zonecfg add device subcommand. However, its physical properties can be
modified only by the global administrator.

For more information about zonecfg syntax, see zonecfg(8).

After a dataset is delegated to a non-global zone, the zoned property is
automatically set. A zoned file system cannot be mounted in the global
zone, since the zone administrator might have to set the mount point to an
unacceptable value.

The global administrator can forcibly clear the zoned property, though this
should be done with extreme care. The global administrator should verify
that all the mount points are acceptable before clearing the property.

Native Properties

Properties are divided into two types, native properties and user-defined
(or "user") properties. Native properties either export internal
statistics or control ZFS behavior. In addition, native properties are
either editable or read-only. User properties have no effect on ZFS
behavior, but you can use them to annotate datasets in a way that is
meaningful in your environment. For more information about user
properties, see the User Properties section, below.

Every dataset has a set of properties that export statistics about the
dataset as well as control various behaviors. Properties are inherited
from the parent unless overridden by the child. Some properties apply only
to certain types of datasets (file systems, volumes, or snapshots).

The values of numeric properties can be specified using human-readable
suffixes (for example, k, KB, M, Gb, and so forth, up to Z for zettabyte).
The following are all valid (and equal) specifications: 1536M, 1.5g,
1.50GB.

The values of non-numeric properties are case sensitive and must be
lowercase, except for mountpoint, sharenfs, and sharesmb.

The following native properties consist of read-only statistics about the
dataset. These properties can be neither set, nor inherited. Native
properties apply to all dataset types unless otherwise noted.

available The amount of space available to the dataset and all
its children, assuming that there is no other
activity in the pool. Because space is shared within
a pool, availability can be limited by any number of
factors, including physical pool size, quotas,
reservations, or other datasets within the pool.

This property can also be referred to by its
shortened column name, avail.

compressratio For non-snapshots, the compression ratio achieved for
the used space of this dataset, expressed as a
multiplier. The used property includes descendant
datasets, and, for clones, does not include the space
shared with the origin snapshot. For snapshots, the
compressratio is the same as the refcompressratio
property. Compression can be turned on by running:
zfs set compression=on dataset. The default value is
off.

createtxg The transaction group (txg) in which the dataset was
created. Bookmarks have the same createtxg as the
snapshot they are initially tied to. This property
is suitable for ordering a list of snapshots, e.g.
for incremental send and receive.

creation The time this dataset was created.

clones For snapshots, this property is a comma-separated
list of filesystems or volumes which are clones of
this snapshot. The clones' origin property is this
snapshot. If the clones property is not empty, then
this snapshot can not be destroyed (even with the -r
or -f options).

defer_destroy This property is on if the snapshot has been marked
for deferred destroy by using the zfs destroy -d
command. Otherwise, the property is off.

encryptionroot For encrypted datasets, indicates where the dataset
is currently inheriting its encryption key from.
Loading or unloading a key for the encryptionroot
will implicitly load / unload the key for any
inheriting datasets (see zfs load-key and zfs
unload-key). Clones will always share an encryption
key with their origin. See the Encryption section
for details.

filesystem_count The total number of filesystems and volumes that
exist under this location in the dataset tree. This
value is only available when a filesystem_limit has
been set somewhere in the tree under which the
dataset resides.

guid The 64 bit GUID of this dataset or bookmark which
does not change over its entire lifetime. When a
snapshot is sent to another pool, the received
snapshot has the same GUID. Thus, the guid is
suitable to identify a snapshot across pools.

keystatus Indicates if an encryption key is currently loaded
into ZFS. The possible values are none, available,
and unavailable. See zfs load-key and zfs
unload-key.

logicalreferenced The amount of space that is "logically" accessible by
this dataset. See the referenced property. The
logical space ignores the effect of the compression
and copies properties, giving a quantity closer to
the amount of data that applications see. However,
it does include space consumed by metadata.

This property can also be referred to by its
shortened column name, lrefer.

logicalused The amount of space that is "logically" consumed by
this dataset and all its descendents. See the used
property. The logical space ignores the effect of
the compression and copies properties, giving a
quantity closer to the amount of data that
applications see. However, it does include space
consumed by metadata.

This property can also be referred to by its
shortened column name, lused.

mounted For file systems, indicates whether the file system
is currently mounted. This property can be either
yes or no.

origin For cloned file systems or volumes, the snapshot from
which the clone was created. See also the clones
property.

receive_resume_token For filesystems or volumes which have saved
partially-completed state from zfs receive -s, this
opaque token can be provided to zfs send -t to resume
and complete the zfs receive.

referenced The amount of data that is accessible by this
dataset, which may or may not be shared with other
datasets in the pool. When a snapshot or clone is
created, it initially references the same amount of
space as the file system or snapshot it was created
from, since its contents are identical.

This property can also be referred to by its
shortened column name, refer.

refcompressratio The compression ratio achieved for the referenced
space of this dataset, expressed as a multiplier.
See also the compressratio property.

snapshot_count The total number of snapshots that exist under this
location in the dataset tree. This value is only
available when a snapshot_limit has been set
somewhere in the tree under which the dataset
resides.

type The type of dataset: filesystem, volume, or snapshot.

used The amount of space consumed by this dataset and all
its descendents. This is the value that is checked
against this dataset's quota and reservation. The
space used does not include this dataset's
reservation, but does take into account the
reservations of any descendent datasets. The amount
of space that a dataset consumes from its parent, as
well as the amount of space that is freed if this
dataset is recursively destroyed, is the greater of
its space used and its reservation.

The used space of a snapshot (see the Snapshots
section) is space that is referenced exclusively by
this snapshot. If this snapshot is destroyed, the
amount of used space will be freed. Space that is
shared by multiple snapshots isn't accounted for in
this metric. When a snapshot is destroyed, space
that was previously shared with this snapshot can
become unique to snapshots adjacent to it, thus
changing the used space of those snapshots. The used
space of the latest snapshot can also be affected by
changes in the file system. Note that the used space
of a snapshot is a subset of the written space of the
snapshot.

The amount of space used, available, or referenced
does not take into account pending changes. Pending
changes are generally accounted for within a few
seconds. Committing a change to a disk using
fsync(3C) or O_SYNC does not necessarily guarantee
that the space usage information is updated
immediately.

usedby* The usedby* properties decompose the used properties
into the various reasons that space is used.
Specifically, used = usedbychildren + usedbydataset +
usedbyrefreservation + usedbysnapshots. These
properties are only available for datasets created on
zpool "version 13" pools.

usedbychildren The amount of space used by children of this dataset,
which would be freed if all the dataset's children
were destroyed.

usedbydataset The amount of space used by this dataset itself,
which would be freed if the dataset were destroyed
(after first removing any refreservation and
destroying any necessary snapshots or descendents).

usedbyrefreservation The amount of space used by a refreservation set on
this dataset, which would be freed if the
refreservation was removed.

usedbysnapshots The amount of space consumed by snapshots of this
dataset. In particular, it is the amount of space
that would be freed if all of this dataset's
snapshots were destroyed. Note that this is not
simply the sum of the snapshots' used properties
because space can be shared by multiple snapshots.

userused@user The amount of space consumed by the specified user in
this dataset. Space is charged to the owner of each
file, as displayed by ls -l. The amount of space
charged is displayed by du and ls -s. See the zfs
userspace subcommand for more information.

Unprivileged users can access only their own space
usage. The root user, or a user who has been granted
the userused privilege with zfs allow, can access
everyone's usage.

The userused@... properties are not displayed by zfs
get all. The user's name must be appended after the
@ symbol, using one of the following forms:

+o POSIX name (for example, joe)

+o POSIX numeric ID (for example, 789)

+o SID name (for example, joe.smith@mydomain)

+o SID numeric ID (for example, S-1-123-456-789)

userobjused@user The userobjused property is similar to userused but
instead it counts the number of objects consumed by a
user. This property counts all objects allocated on
behalf of the user, it may differ from the results of
system tools such as df -i.

When the property xattr=on is set on a file system
additional objects will be created per-file to store
extended attributes. These additional objects are
reflected in the userobjused value and are counted
against the user's userobjquota.

userrefs This property is set to the number of user holds on
this snapshot. User holds are set by using the zfs
hold command.

groupused@group The amount of space consumed by the specified group
in this dataset. Space is charged to the group of
each file, as displayed by ls -l. See the
userused@user property for more information.

Unprivileged users can only access their own groups'
space usage. The root user, or a user who has been
granted the groupused privilege with zfs allow, can
access all groups' usage.

groupobjused@group The number of objects consumed by the specified group
in this dataset. Multiple objects may be charged to
the group for each file when extended attributes are
in use. See the userobjused@user property for more
information.

Unprivileged users can only access their own groups'
space usage. The root user, or a user who has been
granted the groupobjused privilege with zfs allow,
can access all groups' usage.

projectused@project The amount of space consumed by the specified project
in this dataset. Project is identified via the
project identifier (ID) that is object-based numeral
attribute. An object can inherit the project ID from
its parent object (if the parent has the flag of
inherit project ID that can be set and changed via
zfs project -s) when being created. The privileged
user can set and change object's project ID via zfs
project -s anytime. Space is charged to the project
of each file, as displayed by zfs project. See the
userused@user property for more information.

The root user, or a user who has been granted the
projectused privilege with zfs allow, can access all
projects' usage.

projectobjused@project
The projectobjused is similar to projectused but
instead it counts the number of objects consumed by
project. When the property xattr=on is set on a
fileset, ZFS will create additional objects per-file
to store extended attributes. These additional
objects are reflected in the projectobjused value and
are counted against the project's projectobjquota.
See the userobjused@user property for more
information.

The root user, or a user who has been granted the
projectobjused privilege with zfs allow, can access
all projects' objects usage.

volblocksize For volumes, specifies the block size of the volume.
The blocksize cannot be changed once the volume has
been written, so it should be set at volume creation
time. The default blocksize for volumes is 8 Kbytes.
Any power of 2 from 512 bytes to 128 Kbytes is valid.

This property can also be referred to by its
shortened column name, volblock.

written The amount of space referenced by this dataset, that
was written since the previous snapshot (i.e. that is
not referenced by the previous snapshot).

written@snapshot The amount of referenced space written to this
dataset since the specified snapshot. This is the
space that is referenced by this dataset but was not
referenced by the specified snapshot.

The snapshot may be specified as a short snapshot
name (just the part after the @), in which case it
will be interpreted as a snapshot in the same
filesystem as this dataset. The snapshot may be a
full snapshot name (filesystem@snapshot), which for
clones may be a snapshot in the origin's filesystem
(or the origin of the origin's filesystem, etc.)

The following native properties can be used to change the behavior of a ZFS
dataset.

aclinherit=discard|noallow|restricted|passthrough|passthrough-x
Controls how ACEs are inherited when files and directories are created.

discard does not inherit any ACEs.

noallow only inherits inheritable ACEs that specify "deny"
permissions.

restricted default, removes the write_acl and write_owner permissions
when the ACE is inherited.

passthrough inherits all inheritable ACEs without any modifications.

passthrough-x same meaning as passthrough, except that the owner@,
group@, and everyone@ ACEs inherit the execute permission
only if the file creation mode also requests the execute
bit.

When the property value is set to passthrough, files are created with a
mode determined by the inheritable ACEs. If no inheritable ACEs exist
that affect the mode, then the mode is set in accordance to the requested
mode from the application.

aclmode=discard|groupmask|passthrough|restricted
Controls how an ACL is modified during chmod(2) and how inherited ACEs
are modified by the file creation mode.

discard default, deletes all ACEs except for those representing the
mode of the file or directory requested by chmod(2).

groupmask reduces permissions granted by all ALLOW entries found in
the ACL such that they are no greater than the group
permissions specified by the mode.

passthrough indicates that no changes are made to the ACL other than
creating or updating the necessary ACEs to represent the new
mode of the file or directory.

restricted causes the chmod(2) operation to return an error when used
on any file or directory which has a non-trivial ACL, with
entries in addition to those that represent the mode.

chmod(2) is required to change the set user ID, set group ID, or sticky
bit on a file or directory, as they do not have equivalent ACEs. In
order to use chmod(2) on a file or directory with a non-trivial ACL when
aclmode is set to restricted, you must first remove all ACEs except for
those that represent the current mode.

aclimplicit=on|off
Controls whether the owner of an object has "implicit owner rights". If
this property is set to on, then the owner of an object can always
chmod(2) as is expected with traditional POSIX file permissions. If this
property is set to off, then the owner may only chmod(2) an object where
the ACL grants write_acl to the user attempting the action. The default
value is on. Note that aclimplicit=off is only fully effective with
aclmode=passthrough and aclinherit=passthrough because in other
configurations, objects can end up having write_acl granted to the object
owner.

atime=on|off
Controls whether the access time for files is updated when they are read.
Turning this property off avoids producing write traffic when reading
files and can result in significant performance gains, though it might
confuse mailers and other similar utilities. The default value is on.

canmount=on|off|noauto
If this property is set to off, the file system cannot be mounted, and is
ignored by zfs mount -a. Setting this property to off is similar to
setting the mountpoint property to none, except that the dataset still
has a normal mountpoint property, which can be inherited. Setting this
property to off allows datasets to be used solely as a mechanism to
inherit properties. One example of setting canmount=off is to have two
datasets with the same mountpoint, so that the children of both datasets
appear in the same directory, but might have different inherited
characteristics.

When set to noauto, a dataset can only be mounted and unmounted
explicitly. The dataset is not mounted automatically when the dataset is
created or imported, nor is it mounted by the zfs mount -a command or
unmounted by the zfs unmount -a command.

This property is not inherited.

checksum=on|off|fletcher2|fletcher4|sha256|noparity|sha512|skein|edonr
Controls the checksum used to verify data integrity. The default value
is on, which automatically selects an appropriate algorithm (currently,
fletcher4, but this may change in future releases). The value off
disables integrity checking on user data. The value noparity not only
disables integrity but also disables maintaining parity for user data.
This setting is used internally by a dump device residing on a RAID-Z
pool and should not be used by any other dataset. Disabling checksums is
NOT a recommended practice.

The sha512, skein, and edonr checksum algorithms require enabling the
appropriate features on the pool. Please see zpool-features(7) for more
information on these algorithms.

Changing this property affects only newly-written data.

compression=on|off|gzip|gzip-N|lz4|lzjb|zle
Controls the compression algorithm used for this dataset.

Setting compression to on indicates that the current default compression
algorithm should be used. The default balances compression and
decompression speed, with compression ratio and is expected to work well
on a wide variety of workloads. Unlike all other settings for this
property, on does not select a fixed compression type. As new
compression algorithms are added to ZFS and enabled on a pool, the
default compression algorithm may change. The current default
compression algorithm is either lzjb or, if the lz4_compress feature is
enabled, lz4.

The lz4 compression algorithm is a high-performance replacement for the
lzjb algorithm. It features significantly faster compression and
decompression, as well as a moderately higher compression ratio than
lzjb, but can only be used on pools with the lz4_compress feature set to
enabled. See zpool-features(7) for details on ZFS feature flags and the
lz4_compress feature.

The lzjb compression algorithm is optimized for performance while
providing decent data compression.

The gzip compression algorithm uses the same compression as the gzip(1)
command. You can specify the gzip level by using the value gzip-N, where
N is an integer from 1 (fastest) to 9 (best compression ratio).
Currently, gzip is equivalent to gzip-6 (which is also the default for
gzip(1)).

The zle compression algorithm compresses runs of zeros.

This property can also be referred to by its shortened column name
compress. Changing this property affects only newly-written data.

copies=1|2|3
Controls the number of copies of data stored for this dataset. These
copies are in addition to any redundancy provided by the pool, for
example, mirroring or RAID-Z. The copies are stored on different disks,
if possible. The space used by multiple copies is charged to the
associated file and dataset, changing the used property and counting
against quotas and reservations.

Changing this property only affects newly-written data. Therefore, set
this property at file system creation time by using the -o copies=N
option.

devices=on|off
Controls whether device nodes can be opened on this file system. The
default value is on.

encryption=on|off|aes-128-ccm|aes-192-ccm|aes-256-ccm|aes-128-gcm|aes-192-gcm|aes-256-gcm
Controls the encryption cipher suite (block cipher, key length, and mode)
used for this dataset. Requires the encryption feature to be enabled on
the pool. Requires a keyformat to be set at dataset creation time.

Selecting encryption=on when creating a dataset indicates that the
default encryption suite will be selected, which is currently
aes-256-ccm. In order to provide consistent data protection, encryption
must be specified at dataset creation time and it cannot be changed
afterwards.

For more details and caveats about encryption see the Encryption section.

keyformat=raw|hex|passphrase
Controls what format the user's encryption key will be provided as. This
property is only set for encrypted datasets which are encryption roots.

Raw keys and hex keys must be 32 bytes long (regardless of the chosen
encryption suite) and must be randomly generated. A raw key can be
generated with the following command:

# dd if=/dev/urandom of=/path/to/output/key bs=32 count=1

Passphrases must be between 8 and 512 bytes long and will be processed
through PBKDF2 before being used (see the pbkdf2iters property). Even
though the encryption suite cannot be changed after dataset creation, the
keyformat can be with zfs change-key.

keylocation=prompt|file://<absolute file path>
Controls where the user's encryption key will be loaded from by default
for commands such as zfs load-key and zfs mount -l. This property is
only set for encrypted datasets which are encryption roots. If
unspecified, the default is prompt.

Even though the encryption suite cannot be changed after dataset
creation, the keylocation can be with either zfs set or zfs change-key.
If prompt is selected ZFS will ask for the key at the command prompt when
it is required to access the encrypted data (see zfs load-key). This
setting will also allow the key to be passed in via STDIN, but users
should be careful not to place keys which should be kept secret on the
command line. If a file URI is selected, the key will be loaded from the
specified absolute file path.

exec=on|off
Controls whether processes can be executed from within this file system.
The default value is on.

filesystem_limit=count|none
Limits the number of filesystems and volumes that can exist under this
point in the dataset tree. The limit is not enforced if the user is
allowed to change the limit. Setting a filesystem_limit to on a
descendent of a filesystem that already has a filesystem_limit does not
override the ancestor's filesystem_limit, but rather imposes an
additional limit. This feature must be enabled to be used (see
zpool-features(7)).

special_small_blocks=size
This value represents the threshold block size for including small file
blocks into the special allocation class. Blocks smaller than or equal
to this value will be assigned to the special allocation class while
greater blocks will be assigned to the regular class. Valid values are
zero or a power of two from 512B up to 128K. The default size is 0 which
means no small file blocks will be allocated in the special class.

Before setting this property, a special class vdev must be added to the
pool. See zpool(8) for more details on the special allocation class.

mountpoint=path|none|legacy
Controls the mount point used for this file system. See the Mount Points
section for more information on how this property is used.

When the mountpoint property is changed for a file system, the file
system and any children that inherit the mount point are unmounted. If
the new value is legacy, then they remain unmounted. Otherwise, they are
automatically remounted in the new location if the property was
previously legacy or none, or if they were mounted before the property
was changed. In addition, any shared file systems are unshared and
shared in the new location.

nbmand=on|off
Controls whether the file system should be mounted with nbmand (Non
Blocking mandatory locks). This is used for SMB clients. Changes to
this property only take effect when the file system is umounted and
remounted. See mount(8) for more information on nbmand mounts.

pbkdf2iters=iterations
Controls the number of PBKDF2 iterations that a passphrase encryption key
should be run through when processing it into an encryption key. This
property is only defined when encryption is enabled and a keyformat of
passphrase is selected. The goal of PBKDF2 is to significantly increase
the computational difficulty needed to brute force a user's passphrase.
This is accomplished by forcing the attacker to run each passphrase
through a computationally expensive hashing function many times before
they arrive at the resulting key. A user who actually knows the
passphrase will only have to pay this cost once. As CPUs become better
at processing, this number should be raised to ensure that a brute force
attack is still not possible. The current default is 350000 and the
minimum is 100000. This property may be changed with zfs change-key.

primarycache=all|none|metadata
Controls what is cached in the primary cache (ARC). If this property is
set to all, then both user data and metadata is cached. If this property
is set to none, then neither user data nor metadata is cached. If this
property is set to metadata, then only metadata is cached. The default
value is all.

quota=size|none
Limits the amount of space a dataset and its descendents can consume.
This property enforces a hard limit on the amount of space used. This
includes all space consumed by descendents, including file systems and
snapshots. Setting a quota on a descendent of a dataset that already has
a quota does not override the ancestor's quota, but rather imposes an
additional limit.

Quotas cannot be set on volumes, as the volsize property acts as an
implicit quota.

snapshot_limit=count|none
Limits the number of snapshots that can be created on a dataset and its
descendents. Setting a snapshot_limit on a descendent of a dataset that
already has a snapshot_limit does not override the ancestor's
snapshot_limit, but rather imposes an additional limit. The limit is not
enforced if the user is allowed to change the limit. For example, this
means that recursive snapshots taken from the global zone are counted
against each delegated dataset within a zone. This feature must be
enabled to be used (see zpool-features(7)).

userquota@user=size|none
Limits the amount of space consumed by the specified user. User space
consumption is identified by the userspace@user property.

Enforcement of user quotas may be delayed by several seconds. This delay
means that a user might exceed their quota before the system notices that
they are over quota and begins to refuse additional writes with the
EDQUOT error message. See the zfs userspace subcommand for more
information.

Unprivileged users can only access their own groups' space usage. The
root user, or a user who has been granted the userquota privilege with
zfs allow, can get and set everyone's quota.

This property is not available on volumes, on file systems before version
4, or on pools before version 15. The userquota@... properties are not
displayed by zfs get all. The user's name must be appended after the @
symbol, using one of the following forms:

+o POSIX name (for example, joe)

+o POSIX numeric ID (for example, 789)

+o SID name (for example, joe.smith@mydomain)

+o SID numeric ID (for example, S-1-123-456-789)

userobjquota@user=size|none
The userobjquota is similar to userquota but it limits the number of
objects a user can create. Please refer to userobjused for more
information about how objects are counted.

groupquota@group=size|none
Limits the amount of space consumed by the specified group. Group space
consumption is identified by the groupused@group property.

Unprivileged users can access only their own groups' space usage. The
root user, or a user who has been granted the groupquota privilege with
zfs allow, can get and set all groups' quotas.

groupobjquota@group=size|none
The groupobjquota is similar to groupquota but it limits the number of
objects a group can consume. Please refer to userobjused for more
information about how objects are counted.

projectquota@project=size|none
Limits the amount of space consumed by the specified project. Project
space consumption is identified by the projectused@project property.
Please refer to projectused for more information about how project is
identified and set or changed.

The root user, or a user who has been granted the projectquota privilege
with zfs allow, can access all projects' quotas.

projectobjquota@project=size|none
The projectobjquota is similar to projectquota but it limits the number
of objects a project can consume. Please refer to userobjused for more
information about how objects are counted.

readonly=on|off
Controls whether this dataset can be modified. The default value is off.

This property can also be referred to by its shortened column name,
rdonly.

recordsize=size
Specifies a suggested block size for files in the file system. This
property is designed solely for use with database workloads that access
files in fixed-size records. ZFS automatically tunes block sizes
according to internal algorithms optimized for typical access patterns.

For databases that create very large files but access them in small
random chunks, these algorithms may be suboptimal. Specifying a
recordsize greater than or equal to the record size of the database can
result in significant performance gains. Use of this property for
general purpose file systems is strongly discouraged, and may adversely
affect performance.

The size specified must be a power of two greater than or equal to 512
and less than or equal to 128 Kbytes. If the large_blocks feature is
enabled on the pool, the size may be up to 1 Mbyte. See
zpool-features(7) for details on ZFS feature flags.

Changing the file system's recordsize affects only files created
afterward; existing files are unaffected.

This property can also be referred to by its shortened column name,
recsize.

redundant_metadata=all|most
Controls what types of metadata are stored redundantly. ZFS stores an
extra copy of metadata, so that if a single block is corrupted, the
amount of user data lost is limited. This extra copy is in addition to
any redundancy provided at the pool level (e.g. by mirroring or RAID-Z),
and is in addition to an extra copy specified by the copies property (up
to a total of 3 copies). For example if the pool is mirrored, copies=2,
and redundant_metadata=most, then ZFS stores 6 copies of most metadata,
and 4 copies of data and some metadata.

When set to all, ZFS stores an extra copy of all metadata. If a single
on-disk block is corrupt, at worst a single block of user data (which is
recordsize bytes long) can be lost.

When set to most, ZFS stores an extra copy of most types of metadata.
This can improve performance of random writes, because less metadata must
be written. In practice, at worst about 100 blocks (of recordsize bytes
each) of user data can be lost if a single on-disk block is corrupt. The
exact behavior of which metadata blocks are stored redundantly may change
in future releases.

The default value is all.

refquota=size|none
Limits the amount of space a dataset can consume. This property enforces
a hard limit on the amount of space used. This hard limit does not
include space used by descendents, including file systems and snapshots.

refreservation=size|none|auto
The minimum amount of space guaranteed to a dataset, not including its
descendents. When the amount of space used is below this value, the
dataset is treated as if it were taking up the amount of space specified
by refreservation. The refreservation reservation is accounted for in
the parent datasets' space used, and counts against the parent datasets'
quotas and reservations.

If refreservation is set, a snapshot is only allowed if there is enough
free pool space outside of this reservation to accommodate the current
number of "referenced" bytes in the dataset.

If refreservation is set to auto, a volume is thick provisioned (or "not
sparse"). refreservation=auto is only supported on volumes. See volsize
in the Native Properties section for more information about sparse
volumes.

This property can also be referred to by its shortened column name,
refreserv.

reservation=size|none
The minimum amount of space guaranteed to a dataset and its descendants.
When the amount of space used is below this value, the dataset is treated
as if it were taking up the amount of space specified by its reservation.
Reservations are accounted for in the parent datasets' space used, and
count against the parent datasets' quotas and reservations.

This property can also be referred to by its shortened column name,
reserv.

secondarycache=all|none|metadata
Controls what is cached in the secondary cache (L2ARC). If this property
is set to all, then both user data and metadata is cached. If this
property is set to none, then neither user data nor metadata is cached.
If this property is set to metadata, then only metadata is cached. The
default value is all.

setuid=on|off
Controls whether the setuid bit is respected for the file system. The
default value is on.

sharesmb=on|off|opts
Controls whether the file system is shared via SMB, and what options are
to be used. A file system with the sharesmb property set to off is
managed through traditional tools such as sharemgr(8). Otherwise, the
file system is automatically shared and unshared with the zfs share and
zfs unshare commands. If the property is set to on, the sharemgr(8)
command is invoked with no options. Otherwise, the sharemgr(8) command
is invoked with options equivalent to the contents of this property.

Because SMB shares requires a resource name, a unique resource name is
constructed from the dataset name. The constructed name is a copy of the
dataset name except that the characters in the dataset name, which would
be invalid in the resource name, are replaced with underscore (_)
characters. A pseudo property "name" is also supported that allows you
to replace the data set name with a specified name. The specified name
is then used to replace the prefix dataset in the case of inheritance.
For example, if the dataset data/home/john is set to name=john, then
data/home/john has a resource name of john. If a child dataset
data/home/john/backups is shared, it has a resource name of john_backups.

When SMB shares are created, the SMB share name appears as an entry in
the .zfs/shares directory. You can use the ls or chmod command to
display the share-level ACLs on the entries in this directory.

When the sharesmb property is changed for a dataset, the dataset and any
children inheriting the property are re-shared with the new options, only
if the property was previously set to off, or if they were shared before
the property was changed. If the new property is set to off, the file
systems are unshared.

sharenfs=on|off|opts
Controls whether the file system is shared via NFS, and what options are
to be used. A file system with a sharenfs property of off is managed
through traditional tools such as share(8), unshare(8), and dfstab(5).
Otherwise, the file system is automatically shared and unshared with the
zfs share and zfs unshare commands. If the property is set to on,
share(8) command is invoked with no options. Otherwise, the share(8)
command is invoked with options equivalent to the contents of this
property.

When the sharenfs property is changed for a dataset, the dataset and any
children inheriting the property are re-shared with the new options, only
if the property was previously off, or if they were shared before the
property was changed. If the new property is off, the file systems are
unshared.

logbias=latency|throughput
Provide a hint to ZFS about handling of synchronous requests in this
dataset. If logbias is set to latency (the default), ZFS will use pool
log devices (if configured) to handle the requests at low latency. If
logbias is set to throughput, ZFS will not use configured pool log
devices. ZFS will instead optimize synchronous operations for global
pool throughput and efficient use of resources.

snapdir=hidden|visible
Controls whether the .zfs directory is hidden or visible in the root of
the file system as discussed in the Snapshots section. The default value
is hidden.

sync=standard|always|disabled
Controls the behavior of synchronous requests (e.g. fsync, O_DSYNC).
standard is the POSIX specified behavior of ensuring all synchronous
requests are written to stable storage and all devices are flushed to
ensure data is not cached by device controllers (this is the default).
always causes every file system transaction to be written and flushed
before its system call returns. This has a large performance penalty.
disabled disables synchronous requests. File system transactions are
only committed to stable storage periodically. This option will give the
highest performance. However, it is very dangerous as ZFS would be
ignoring the synchronous transaction demands of applications such as
databases or NFS. Administrators should only use this option when the
risks are understood.

version=N|current
The on-disk version of this file system, which is independent of the pool
version. This property can only be set to later supported versions. See
the zfs upgrade command.

volsize=size
For volumes, specifies the logical size of the volume. By default,
creating a volume establishes a reservation of equal size. For storage
pools with a version number of 9 or higher, a refreservation is set
instead. Any changes to volsize are reflected in an equivalent change to
the reservation (or refreservation). The volsize can only be set to a
multiple of volblocksize, and cannot be zero.

The reservation is kept equal to the volume's logical size to prevent
unexpected behavior for consumers. Without the reservation, the volume
could run out of space, resulting in undefined behavior or data
corruption, depending on how the volume is used. These effects can also
occur when the volume size is changed while it is in use (particularly
when shrinking the size). Extreme care should be used when adjusting the
volume size.

Though not recommended, a "sparse volume" (also known as "thin
provisioned") can be created by specifying the -s option to the zfs
create -V command, or by changing the value of the refreservation
property (or reservation property on pool version 8 or earlier) after the
volume has been created. A "sparse volume" is a volume where the value
of refreservation is less than the size of the volume plus the space
required to store its metadata. Consequently, writes to a sparse volume
can fail with ENOSPC when the pool is low on space. For a sparse volume,
changes to volsize are not reflected in the refreservation. A volume
that is not sparse is said to be "thick provisioned". A sparse volume
can become thick provisioned by setting refreservation to auto.

vscan=on|off
Controls whether regular files should be scanned for viruses when a file
is opened and closed. In addition to enabling this property, the virus
scan service must also be enabled for virus scanning to occur. The
default value is off.

xattr=on|off
Controls whether extended attributes are enabled for this file system.
The default value is on.

zoned=on|off
Controls whether the dataset is managed from a non-global zone. See the
Zones section for more information. The default value is off.

The following three properties cannot be changed after the file system is
created, and therefore, should be set when the file system is created. If
the properties are not set with the zfs create or zpool create commands,
these properties are inherited from the parent dataset. If the parent
dataset lacks these properties due to having been created prior to these
features being supported, the new file system will have the default values
for these properties.

casesensitivity=sensitive|insensitive|mixed
Indicates whether the file name matching algorithm used by the file
system should be case-sensitive, case-insensitive, or allow a combination
of both styles of matching. The default value for the casesensitivity
property is sensitive. Traditionally, UNIX and POSIX file systems have
case-sensitive file names.

The mixed value for the casesensitivity property indicates that the file
system can support requests for both case-sensitive and case-insensitive
matching behavior. Currently, case-insensitive matching behavior on a
file system that supports mixed behavior is limited to the SMB server
product. For more information about the mixed value behavior, see the
"ZFS Administration Guide".

normalization=none|formC|formD|formKC|formKD
Indicates whether the file system should perform a unicode normalization
of file names whenever two file names are compared, and which
normalization algorithm should be used. File names are always stored
unmodified, names are normalized as part of any comparison process. If
this property is set to a legal value other than none, and the utf8only
property was left unspecified, the utf8only property is automatically set
to on. The default value of the normalization property is none. This
property cannot be changed after the file system is created.

utf8only=on|off
Indicates whether the file system should reject file names that include
characters that are not present in the UTF-8 character code set. If this
property is explicitly set to off, the normalization property must either
not be explicitly set or be set to none. The default value for the
utf8only property is off. This property cannot be changed after the file
system is created.

The casesensitivity, normalization, and utf8only properties are also new
permissions that can be assigned to non-privileged users by using the ZFS
delegated administration feature.

Temporary Mount Point Properties

When a file system is mounted, either through mount(8) for legacy mounts or
the zfs mount command for normal file systems, its mount options are set
according to its properties. The correlation between properties and mount
options is as follows:

PROPERTY MOUNT OPTION
devices devices/nodevices
exec exec/noexec
readonly ro/rw
setuid setuid/nosetuid
xattr xattr/noxattr

In addition, these options can be set on a per-mount basis using the -o
option, without affecting the property that is stored on disk. The values
specified on the command line override the values stored in the dataset.
The nosuid option is an alias for nodevices,nosetuid. These properties are
reported as "temporary" by the zfs get command. If the properties are
changed while the dataset is mounted, the new setting overrides any
temporary settings.

User Properties

In addition to the standard native properties, ZFS supports arbitrary user
properties. User properties have no effect on ZFS behavior, but
applications or administrators can use them to annotate datasets (file
systems, volumes, and snapshots).

User property names must contain a colon (":") character to distinguish
them from native properties. They may contain lowercase letters, numbers,
and the following punctuation characters: colon (":"), dash ("-"), period
("."), and underscore ("_"). The expected convention is that the property
name is divided into two portions such as module:property, but this
namespace is not enforced by ZFS. User property names can be at most 256
characters, and cannot begin with a dash ("-").

When making programmatic use of user properties, it is strongly suggested
to use a reversed DNS domain name for the module component of property
names to reduce the chance that two independently-developed packages use
the same property name for different purposes.

The values of user properties are arbitrary strings, are always inherited,
and are never validated. All of the commands that operate on properties
(zfs list, zfs get, zfs set, and so forth) can be used to manipulate both
native properties and user properties. Use the zfs inherit command to
clear a user property. If the property is not defined in any parent
dataset, it is removed entirely. Property values are limited to 8192
bytes.

ZFS Volumes as Swap or Dump Devices

During an initial installation a swap device and dump device are created on
ZFS volumes in the ZFS root pool. By default, the swap area size is based
on 1/2 the size of physical memory up to 2 Gbytes. The size of the dump
device depends on the kernel's requirements at installation time. Separate
ZFS volumes must be used for the swap area and dump devices. Do not swap
to a file on a ZFS file system. A ZFS swap file configuration is not
supported.

If you need to change your swap area or dump device after the system is
installed or upgraded, use the swap(8) and dumpadm(8) commands.

Encryption

Enabling the encryption feature allows for the creation of encrypted
filesystems and volumes. ZFS will encrypt all user data including file and
zvol data, file attributes, ACLs, permission bits, directory listings, FUID
mappings, and userused/groupused data. ZFS will not encrypt metadata
related to the pool structure, including dataset names, dataset hierarchy,
file size, file holes, and dedup tables. Key rotation is managed
internally by the ZFS kernel module and changing the user's key does not
require re-encrypting the entire dataset. Datasets can be scrubbed,
resilvered, renamed, and deleted without the encryption keys being loaded
(see the zfs load-key subcommand for more info on key loading).

Creating an encrypted dataset requires specifying the encryption and
keyformat properties at creation time, along with an optional keylocation
and pbkdf2iters. After entering an encryption key, the created dataset
will become an encryption root. Any descendant datasets will inherit their
encryption key from the encryption root by default, meaning that loading,
unloading, or changing the key for the encryption root will implicitly do
the same for all inheriting datasets. If this inheritance is not desired,
simply supply a keyformat when creating the child dataset or use zfs
change-key to break an existing relationship, creating a new encryption
root on the child. Note that the child's keyformat may match that of the
parent while still creating a new encryption root, and that changing the
encryption property alone does not create a new encryption root; this would
simply use a different cipher suite with the same key as its encryption
root. The one exception is that clones will always use their origin's
encryption key. As a result of this exception, some encryption-related
properties (namely keystatus, keyformat, keylocation, and pbkdf2iters) do
not inherit like other ZFS properties and instead use the value determined
by their encryption root. Encryption root inheritance can be tracked via
the read-only encryptionroot property.

Encryption changes the behavior of a few ZFS operations. Encryption is
applied after compression so compression ratios are preserved. Normally
checksums in ZFS are 256 bits long, but for encrypted data the checksum is
128 bits of the user-chosen checksum and 128 bits of MAC from the
encryption suite, which provides additional protection against maliciously
altered data. Deduplication is still possible with encryption enabled but
for security, datasets will only dedup against themselves, their snapshots,
and their clones.

There are a few limitations on encrypted datasets. Encrypted data cannot
be embedded via the embedded_data feature. Encrypted datasets may not have
copies=3 since the implementation stores some encryption metadata where the
third copy would normally be. Since compression is applied before
encryption datasets may be vulnerable to a CRIME-like attack if
applications accessing the data allow for it. Deduplication with
encryption will leak information about which blocks are equivalent in a
dataset and will incur an extra CPU cost per block written.

SUBCOMMANDS

All subcommands that modify state are logged persistently to the pool in
their original form.

zfs -?
Displays a help message.

zfs create [-Pnpv] [-o property=value]... filesystem
Creates a new ZFS file system. The file system is automatically mounted
according to the mountpoint property inherited from the parent.

-o property=value
Sets the specified property as if the command zfs set property=value
was invoked at the same time the dataset was created. Any editable
ZFS property can also be set at creation time. Multiple -o options
can be specified. An error results if the same property is specified
in multiple -o options.

-p Creates all the non-existing parent datasets. Datasets created in
this manner are automatically mounted according to the mountpoint
property inherited from their parent. Any property specified on the
command line using the -o option is ignored. If the target
filesystem already exists, the operation completes successfully.

-n Do a dry-run ("No-op") creation. No datasets will be created. This
is useful in conjunction with the -v or -P flags to validate
properties that are passed via -o options and those implied by other
options. The actual dataset creation can still fail due to
insufficient privileges or available capacity.

-P Print machine-parsable verbose information about the created dataset.
Each line of output contains a key and one or two values, all
separated by tabs. The create_ancestors and create keys have
filesystem as their only value. The create_ancestors key only
appears if the -p option is used. The property key has two values, a
property's name and that property's value. The property key may
appear zero or more times, once for each property that will be set
local to filesystem due to the use of the -o option.

-v Print verbose information about the created dataset.

zfs create [-ps] [-b blocksize] [-o property=value]... -V size volume
Creates a volume of the given size. The volume is exported as a block
device in /dev/zvol/{dsk,rdsk}/path, where path is the name of the volume
in the ZFS namespace. The size represents the logical size as exported
by the device. By default, a reservation of equal size is created.

size is automatically rounded up to the nearest 128 Kbytes to ensure that
the volume has an integral number of blocks regardless of blocksize.

-b blocksize
Equivalent to -o volblocksize=blocksize. If this option is specified
in conjunction with -o volblocksize, the resulting behavior is
undefined.

-o property=value
Sets the specified property as if the zfs set property=value command
was invoked at the same time the dataset was created. Any editable
ZFS property can also be set at creation time. Multiple -o options
can be specified. An error results if the same property is specified
in multiple -o options.

-p Creates all the non-existing parent datasets. Datasets created in
this manner are automatically mounted according to the mountpoint
property inherited from their parent. Any property specified on the
command line using the -o option is ignored. If the target
filesystem already exists, the operation completes successfully.

-s Creates a sparse volume with no reservation. See volsize in the
Native Properties section for more information about sparse volumes.

-n Do a dry-run ("No-op") creation. No datasets will be created. This
is useful in conjunction with the -v or -P flags to validate
properties that are passed via -o options and those implied by other
options. The actual dataset creation can still fail due to
insufficient privileges or available capacity.

-P Print machine-parsable verbose information about the created dataset.
Each line of output contains a key and one or two values, all
separated by tabs. The create_ancestors and create keys have volume
as their only value. The create_ancestors key only appears if the -p
option is used. The property key has two values, a property's name
and that property's value. The property key may appear zero or more
times, once for each property that will be set local to volume due to
the use of the -b or -o options, as well as refreservation if the
volume is not sparse.

-v Print verbose information about the created dataset.

zfs destroy [-Rfnprv] filesystem|volume
Destroys the given dataset. By default, the command unshares any file
systems that are currently shared, unmounts any file systems that are
currently mounted, and refuses to destroy a dataset that has active
dependents (children or clones).

-R Recursively destroy all dependents, including cloned file systems
outside the target hierarchy.

-f Force an unmount of any file systems using the unmount -f command.
This option has no effect on non-file systems or unmounted file
systems.

-n Do a dry-run ("No-op") deletion. No data will be deleted. This is
useful in conjunction with the -v or -p flags to determine what data
would be deleted.

-p Print machine-parsable verbose information about the deleted data.

-r Recursively destroy all children.

-v Print verbose information about the deleted data.

Extreme care should be taken when applying either the -r or the -R
options, as they can destroy large portions of a pool and cause
unexpected behavior for mounted file systems in use.

zfs destroy [-Rdnprv] filesystem|volume@snap[%snap[,snap[%snap]]]...
The given snapshots are destroyed immediately if and only if the zfs
destroy command without the -d option would have destroyed it. Such
immediate destruction would occur, for example, if the snapshot had no
clones and the user-initiated reference count were zero.

If a snapshot does not qualify for immediate destruction, it is marked
for deferred deletion. In this state, it exists as a usable, visible
snapshot until both of the preconditions listed above are met, at which
point it is destroyed.

An inclusive range of snapshots may be specified by separating the first
and last snapshots with a percent sign. The first and/or last snapshots
may be left blank, in which case the filesystem's oldest or newest
snapshot will be implied.

Multiple snapshots (or ranges of snapshots) of the same filesystem or
volume may be specified in a comma-separated list of snapshots. Only the
snapshot's short name (the part after the @) should be specified when
using a range or comma-separated list to identify multiple snapshots.

-R Recursively destroy all clones of these snapshots, including the
clones, snapshots, and children. If this flag is specified, the -d
flag will have no effect.

-d Defer snapshot deletion.

-n Do a dry-run ("No-op") deletion. No data will be deleted. This is
useful in conjunction with the -p or -v flags to determine what data
would be deleted.

-p Print machine-parsable verbose information about the deleted data.

-r Destroy (or mark for deferred deletion) all snapshots with this name
in descendent file systems.

-v Print verbose information about the deleted data.

Extreme care should be taken when applying either the -r or the -R
options, as they can destroy large portions of a pool and cause
unexpected behavior for mounted file systems in use.

zfs destroy filesystem|volume#bookmark
The given bookmark is destroyed.

zfs snapshot [-r] [-o property=value]...
filesystem@snapname|volume@snapname...
Creates snapshots with the given names. All previous modifications by
successful system calls to the file system are part of the snapshots.
Snapshots are taken atomically, so that all snapshots correspond to the
same moment in time. See the Snapshots section for details.

-o property=value
Sets the specified property; see zfs create for details.

-r Recursively create snapshots of all descendent datasets

zfs rollback [-Rfr] snapshot
Roll back the given dataset to a previous snapshot. When a dataset is
rolled back, all data that has changed since the snapshot is discarded,
and the dataset reverts to the state at the time of the snapshot. By
default, the command refuses to roll back to a snapshot other than the
most recent one. In order to do so, all intermediate snapshots and
bookmarks must be destroyed by specifying the -r option.

The -rR options do not recursively destroy the child snapshots of a
recursive snapshot. Only direct snapshots of the specified filesystem
are destroyed by either of these options. To completely roll back a
recursive snapshot, you must rollback the individual child snapshots.

-R Destroy any more recent snapshots and bookmarks, as well as any
clones of those snapshots.

-f Used with the -R option to force an unmount of any clone file systems
that are to be destroyed.

-r Destroy any snapshots and bookmarks more recent than the one
specified.

zfs clone [-p] [-o property=value]... snapshot filesystem|volume
Creates a clone of the given snapshot. See the Clones section for
details. The target dataset can be located anywhere in the ZFS
hierarchy, and is created as the same type as the original.

-o property=value
Sets the specified property; see zfs create for details.

-p Creates all the non-existing parent datasets. Datasets created in
this manner are automatically mounted according to the mountpoint
property inherited from their parent. If the target filesystem or
volume already exists, the operation completes successfully.

zfs promote clone-filesystem
Promotes a clone file system to no longer be dependent on its "origin"
snapshot. This makes it possible to destroy the file system that the
clone was created from. The clone parent-child dependency relationship
is reversed, so that the origin file system becomes a clone of the
specified file system.

The snapshot that was cloned, and any snapshots previous to this
snapshot, are now owned by the promoted clone. The space they use moves
from the origin file system to the promoted clone, so enough space must
be available to accommodate these snapshots. No new space is consumed by
this operation, but the space accounting is adjusted. The promoted clone
must not have any conflicting snapshot names of its own. The rename
subcommand can be used to rename any conflicting snapshots.

zfs rename [-f] filesystem|volume|snapshot filesystem|volume|snapshot

zfs rename [-fp] filesystem|volume filesystem|volume
Renames the given dataset. The new target can be located anywhere in the
ZFS hierarchy, with the exception of snapshots. Snapshots can only be
renamed within the parent file system or volume. When renaming a
snapshot, the parent file system of the snapshot does not need to be
specified as part of the second argument. Renamed file systems can
inherit new mount points, in which case they are unmounted and remounted
at the new mount point.

-f Force unmount any filesystems that need to be unmounted in the
process.

-p Creates all the nonexistent parent datasets. Datasets created in
this manner are automatically mounted according to the mountpoint
property inherited from their parent.

zfs rename -r snapshot snapshot
Recursively rename the snapshots of all descendent datasets. Snapshots
are the only dataset that can be renamed recursively.

zfs list [-r|-d depth] [-Hp] [-o property[,property]...] [-s property]...
[-S property]... [-t type[,type]...] [filesystem|volume|snapshot]...
Lists the property information for the given datasets in tabular form.
If specified, you can list property information by the absolute pathname
or the relative pathname. By default, all file systems and volumes are
displayed. Snapshots are displayed if the listsnaps property is on (the
default is off). The following fields are displayed,
name,used,available,referenced,mountpoint.

-H Used for scripting mode. Do not print headers and separate fields by
a single tab instead of arbitrary white space.

-S property
Same as the -s option, but sorts by property in descending order.

-d depth
Recursively display any children of the dataset, limiting the
recursion to depth. A depth of 1 will display only the dataset and
its direct children.

-o property
A comma-separated list of properties to display. The property must
be:

+o One of the properties described in the Native Properties section

+o A user property

+o The value name to display the dataset name

+o The value space to display space usage properties on file systems
and volumes. This is a shortcut for specifying -o
name,avail,used,usedsnap,usedds,usedrefreserv,usedchild -t
filesystem,volume syntax.

-p Display numbers in parsable (exact) values.

-r Recursively display any children of the dataset on the command line.

-s property
A property for sorting the output by column in ascending order based
on the value of the property. The property must be one of the
properties described in the Properties section, or the special value
name to sort by the dataset name. Multiple properties can be
specified at one time using multiple -s property options. Multiple
-s options are evaluated from left to right in decreasing order of
importance. The following is a list of sorting criteria:

+o Numeric types sort in numeric order.

+o String types sort in alphabetical order.

+o Types inappropriate for a row sort that row to the literal
bottom, regardless of the specified ordering.

If no sorting options are specified the existing behavior of zfs list
is preserved.

-t type
A comma-separated list of types to display, where type is one of
filesystem, snapshot, volume, bookmark, or all. For example,
specifying -t snapshot displays only snapshots.

zfs set property=value [property=value]... filesystem|volume|snapshot...
Sets the property or list of properties to the given value(s) for each
dataset. Only some properties can be edited. See the Properties section
for more information on what properties can be set and acceptable values.
Numeric values can be specified as exact values, or in a human-readable
form with a suffix of B, K, M, G, T, P, E, Z (for bytes, kilobytes,
megabytes, gigabytes, terabytes, petabytes, exabytes, or zettabytes,
respectively). User properties can be set on snapshots. For more
information, see the User Properties section.

zfs get [-r|-d depth] [-Hp] [-o field[,field]...] [-s source[,source]...]
[-t type[,type]...] all | property[,property]...
filesystem|volume|snapshot|bookmark...
Displays properties for the given datasets. If no datasets are
specified, then the command displays properties for all datasets on the
system. For each property, the following columns are displayed:

name Dataset name
property Property name
value Property value
source Property source. Can either be local, default,
temporary, inherited, or none (-).

All columns are displayed by default, though this can be controlled by
using the -o option. This command takes a comma-separated list of
properties as described in the Native Properties and User Properties
sections.

The special value all can be used to display all properties that apply to
the given dataset's type (filesystem, volume, snapshot, or bookmark).

-H Display output in a form more easily parsed by scripts. Any headers
are omitted, and fields are explicitly separated by a single tab
instead of an arbitrary amount of space.

-d depth
Recursively display any children of the dataset, limiting the
recursion to depth. A depth of 1 will display only the dataset and
its direct children.

-o field
A comma-separated list of columns to display.
name,property,value,source is the default value.

-p Display numbers in parsable (exact) values.

-r Recursively display properties for any children.

-s source
A comma-separated list of sources to display. Those properties
coming from a source other than those in this list are ignored. Each
source must be one of the following: local, default, inherited,
temporary, and none. The default value is all sources.

-t type
A comma-separated list of types to display, where type is one of
filesystem, snapshot, volume, bookmark, or all.

zfs inherit [-rS] property filesystem|volume|snapshot...
Clears the specified property, causing it to be inherited from an
ancestor, restored to default if no ancestor has the property set, or
with the -S option reverted to the received value if one exists. See the
Properties section for a listing of default values, and details on which
properties can be inherited.

-r Recursively inherit the given property for all children.

-S Revert the property to the received value if one exists; otherwise
operate as if the -S option was not specified.

zfs remap filesystem|volume
Remap the indirect blocks in the given filesystem or volume so that they
no longer reference blocks on previously removed vdevs and we can
eventually shrink the size of the indirect mapping objects for the
previously removed vdevs. Note that remapping all blocks might not be
possible and that references from snapshots will still exist and cannot
be remapped.

zfs upgrade
Displays a list of file systems that are not the most recent version.

zfs upgrade -v
Displays a list of currently supported file system versions.

zfs upgrade [-r] [-V version] -a | filesystem
Upgrades file systems to a new on-disk version. Once this is done, the
file systems will no longer be accessible on systems running older
versions of the software. zfs send streams generated from new snapshots
of these file systems cannot be accessed on systems running older
versions of the software.

In general, the file system version is independent of the pool version.
See zpool(8) for information on the zpool upgrade command.

In some cases, the file system version and the pool version are
interrelated and the pool version must be upgraded before the file system
version can be upgraded.

-V version
Upgrade to the specified version. If the -V flag is not specified,
this command upgrades to the most recent version. This option can
only be used to increase the version number, and only up to the most
recent version supported by this software.

-a Upgrade all file systems on all imported pools.

filesystem
Upgrade the specified file system.

-r Upgrade the specified file system and all descendent file systems.

zfs userspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]... [-t
type[,type]...] filesystem|snapshot
Displays space consumed by, and quotas on, each user in the specified
filesystem or snapshot. This corresponds to the userused@user,
userobjused@user, userquota@user, and userobjquota@user properties.

-H Do not print headers, use tab-delimited output.

-S field
Sort by this field in reverse order. See -s.

-i Translate SID to POSIX ID. The POSIX ID may be ephemeral if no
mapping exists. Normal POSIX interfaces (for example, stat(2), ls
-l) perform this translation, so the -i option allows the output from
zfs userspace to be compared directly with those utilities. However,
-i may lead to confusion if some files were created by an SMB user
before a SMB-to-POSIX name mapping was established. In such a case,
some files will be owned by the SMB entity and some by the POSIX
entity. However, the -i option will report that the POSIX entity has
the total usage and quota for both.

-n Print numeric ID instead of user/group name.

-o field[,field]...
Display only the specified fields from the following set: type, name,
used, quota. The default is to display all fields.

-p Use exact (parsable) numeric output.

-s field
Sort output by this field. The -s and -S flags may be specified
multiple times to sort first by one field, then by another. The
default is -s type -s name.

-t type[,type]...
Print only the specified types from the following set: all,
posixuser, smbuser, posixgroup, smbgroup. The default is -t
posixuser,smbuser. The default can be changed to include group
types.

zfs groupspace [-Hinp] [-o field[,field]...] [-s field]... [-S field]...
[-t type[,type]...] filesystem|snapshot
Displays space consumed by, and quotas on, each group in the specified
filesystem or snapshot. This subcommand is identical to zfs userspace,
except that the default types to display are -t posixgroup,smbgroup.

zfs projectspace [-Hp] [-o field[,field]...] [-s field]... [-S field]...
filesystem|snapshot
Displays space consumed by, and quotas on, each project in the specified
filesystem or snapshot. This subcommand is identical to zfs userspace,
except that the project identifier is numeral, not name. So need neither
the option -i for SID to POSIX ID nor -n for numeric ID, nor -t for
types.

zfs project [-d|-r] file|directory...
List project identifier (ID) and inherit flag of files or directories.

-d Show the directory project ID and inherit flag, not its children. It
will overwrite the former specified -r option.

-r Show on subdirectories recursively. It will overwrite the former
specified -d option.

zfs project -C [-kr] file|directory...
Clear project inherit flag and/or ID on the files or directories.

-k Keep the project ID unchanged. If not specified, the project ID will
be reset as zero.

-r Clear on subdirectories recursively.

zfs project -c [-0] [-d|-r] [-p id] file|directory...
Check project ID and inherit flag on the files or directories, report the
entries without project inherit flag or with different project IDs from
the specified (via -p option) value or the target directory's project ID.

-0 Print file name with a trailing NUL instead of newline (by default),
like "find -print0".

-d Check the directory project ID and inherit flag, not its children.
It will overwrite the former specified -r option.

-p Specify the referenced ID for comparing with the target files or
directories' project IDs. If not specified, the target (top)
directory's project ID will be used as the referenced one.

-r Check on subdirectories recursively. It will overwrite the former
specified -d option.

zfs project [-p id] [-rs] file|directory...
Set project ID and/or inherit flag on the files or directories.

-p Set the files' or directories' project ID with the given value.

-r Set on subdirectories recursively.

-s Set project inherit flag on the given files or directories. It is
usually used for setup tree quota on the directory target with -r
option specified together. When setup tree quota, by default the
directory's project ID will be set to all its descendants unless you
specify the project ID via -p option explicitly.

zfs mount
Displays all ZFS file systems currently mounted.

zfs mount [-Olv] [-o options] -a | filesystem
Mounts ZFS file systems.

-O Perform an overlay mount. See mount(8) for more information.

-a Mount all available ZFS file systems. Invoked automatically as part
of the boot process.

-l Load keys for encrypted filesystems as they are being mounted. This
is equivalent to executing zfs load-key on each encryption root
before mounting it. Note that if a filesystem has a keylocation of
prompt this will cause the terminal to interactively block after
asking for the key.

filesystem
Mount the specified filesystem.

-o options
An optional, comma-separated list of mount options to use temporarily
for the duration of the mount. See the Temporary Mount Point
Properties section for details.

-v Report mount progress.

zfs unmount [-f] -a | filesystem|mountpoint
Unmounts currently mounted ZFS file systems.

-a Unmount all available ZFS file systems. Invoked automatically as
part of the shutdown process.

filesystem|mountpoint
Unmount the specified filesystem. The command can also be given a
path to a ZFS file system mount point on the system.

-f Forcefully unmount the file system, even if it is currently in use.

zfs share -a | filesystem
Shares available ZFS file systems.

-a Share all available ZFS file systems. Invoked automatically as part
of the boot process.

filesystem
Share the specified filesystem according to the sharenfs and sharesmb
properties. File systems are shared when the sharenfs or sharesmb
property is set.

zfs unshare -a | filesystem|mountpoint
Unshares currently shared ZFS file systems.

-a Unshare all available ZFS file systems. Invoked automatically as
part of the shutdown process.

filesystem|mountpoint
Unshare the specified filesystem. The command can also be given a
path to a ZFS file system shared on the system.

zfs bookmark snapshot bookmark
Creates a bookmark of the given snapshot. Bookmarks mark the point in
time when the snapshot was created, and can be used as the incremental
source for a zfs send command.

This feature must be enabled to be used. See zpool-features(7) for
details on ZFS feature flags and the bookmarks feature.

zfs send [-DLPRbcehnpvw] [[-I|-i] snapshot] snapshot
Creates a stream representation of the second snapshot, which is written
to standard output. The output can be redirected to a file or to a
different system (for example, using ssh(1)). By default, a full stream
is generated.

-D, --dedup
Generate a deduplicated stream. Blocks which would have been sent
multiple times in the send stream will only be sent once. The
receiving system must also support this feature to receive a
deduplicated stream. This flag can be used regardless of the
dataset's dedup property, but performance will be much better if the
filesystem uses a dedup-capable checksum (for example, sha256).

-I snapshot
Generate a stream package that sends all intermediary snapshots from
the first snapshot to the second snapshot. For example, -I @a fs@d
is similar to -i @a fs@b; -i @b fs@c; -i @c fs@d. The incremental
source may be specified as with the -i option.

-L, --large-block
Generate a stream which may contain blocks larger than 128KB. This
flag has no effect if the large_blocks pool feature is disabled, or
if the recordsize property of this filesystem has never been set
above 128KB. The receiving system must have the large_blocks pool
feature enabled as well. See zpool-features(7) for details on ZFS
feature flags and the large_blocks feature.

-P, --parsable
Print machine-parsable verbose information about the stream package
generated.

-R, --replicate
Generate a replication stream package, which will replicate the
specified file system, and all descendent file systems, up to the
named snapshot. When received, all properties, snapshots, descendent
file systems, and clones are preserved.

If the -i or -I flags are used in conjunction with the -R flag, an
incremental replication stream is generated. The current values of
properties, and current snapshot and file system names are set when
the stream is received. If the -F flag is specified when this stream
is received, snapshots and file systems that do not exist on the
sending side are destroyed. If the -R flag is used to send encrypted
datasets, then -w must also be specified.

-e, --embed
Generate a more compact stream by using WRITE_EMBEDDED records for
blocks which are stored more compactly on disk by the embedded_data
pool feature. This flag has no effect if the embedded_data feature
is disabled. The receiving system must have the embedded_data
feature enabled. If the lz4_compress feature is active on the
sending system, then the receiving system must have that feature
enabled as well. Datasets that are sent with this flag may not be
received as an encrypted dataset, since encrypted datasets cannot use
the embedded_data feature. See zpool-features(7) for details on ZFS
feature flags and the embedded_data feature.

-b, --backup
Sends only received property values whether or not they are
overridden by local settings, but only if the dataset has ever been
received. Use this option when you want zfs receive to restore
received properties backed up on the sent dataset and to avoid
sending local settings that may have nothing to do with the source
dataset, but only with how the data is backed up.

-c, --compressed
Generate a more compact stream by using compressed WRITE records for
blocks which are compressed on disk and in memory (see the
compression property for details). If the lz4_compress feature is
active on the sending system, then the receiving system must have
that feature enabled as well. If the large_blocks feature is enabled
on the sending system but the -L option is not supplied in
conjunction with -c, then the data will be decompressed before
sending so it can be split into smaller block sizes.

-h, --holds
Generate a stream package that includes any snapshot holds (created
with the zfs hold command), and indicating to zfs receive that the
holds be applied to the dataset on the receiving system.

-i snapshot
Generate an incremental stream from the first snapshot (the
incremental source) to the second snapshot (the incremental target).
The incremental source can be specified as the last component of the
snapshot name (the @ character and following) and it is assumed to be
from the same file system as the incremental target.

If the destination is a clone, the source may be the origin snapshot,
which must be fully specified (for example, pool/fs@origin, not just
@origin).

-n, --dryrun
Do a dry-run ("No-op") send. Do not generate any actual send data.
This is useful in conjunction with the -v or -P flags to determine
what data will be sent. In this case, the verbose output will be
written to standard output (contrast with a non-dry-run, where the
stream is written to standard output and the verbose output goes to
standard error).

-p, --props
Include the dataset's properties in the stream. This flag is
implicit when -R is specified. The receiving system must also
support this feature. Sends of encrypted datasets must use -w when
using this flag.

-w, --raw
For encrypted datasets, send data exactly as it exists on disk. This
allows backups to be taken even if encryption keys are not currently
loaded. The backup may then be received on an untrusted machine
since that machine will not have the encryption keys to read the
protected data or alter it without being detected. Upon being
received, the dataset will have the same encryption keys as it did on
the send side, although the keylocation property will be defaulted to
prompt if not otherwise provided. For unencrypted datasets, this
flag will be equivalent to -Lec. Note that if you do not use this
flag for sending encrypted datasets, data will be sent unencrypted
and may be re-encrypted with a different encryption key on the
receiving system, which will disable the ability to do a raw send to
that system for incrementals.

-v, --verbose
Print verbose information about the stream package generated. This
information includes a per-second report of how much data has been
sent.

The format of the stream is committed. You will be able to receive
your streams on future versions of ZFS .

zfs send [-Lcew] [-i snapshot|bookmark] filesystem|volume|snapshot
Generate a send stream, which may be of a filesystem, and may be
incremental from a bookmark. If the destination is a filesystem or
volume, the pool must be read-only, or the filesystem must not be
mounted. When the stream generated from a filesystem or volume is
received, the default snapshot name will be "--head--".

-L, --large-block
Generate a stream which may contain blocks larger than 128KB. This
flag has no effect if the large_blocks pool feature is disabled, or
if the recordsize property of this filesystem has never been set
above 128KB. The receiving system must have the large_blocks pool
feature enabled as well. See zpool-features(7) for details on ZFS
feature flags and the large_blocks feature.

-c, --compressed
Generate a more compact stream by using compressed WRITE records for
blocks which are compressed on disk and in memory (see the
compression property for details). If the lz4_compress feature is
active on the sending system, then the receiving system must have
that feature enabled as well. If the large_blocks feature is enabled
on the sending system but the -L option is not supplied in
conjunction with -c, then the data will be decompressed before
sending so it can be split into smaller block sizes.

-e, --embed
Generate a more compact stream by using WRITE_EMBEDDED records for
blocks which are stored more compactly on disk by the embedded_data
pool feature. This flag has no effect if the embedded_data feature
is disabled. The receiving system must have the embedded_data
feature enabled. If the lz4_compress feature is active on the
sending system, then the receiving system must have that feature
enabled as well. Datasets that are sent with this flag may not be
received as an encrypted dataset, since encrypted datasets cannot use
the embedded_data feature. See zpool-features(7) for details on ZFS
feature flags and the embedded_data feature.

-i snapshot|bookmark
Generate an incremental send stream. The incremental source must be
an earlier snapshot in the destination's history. It will commonly
be an earlier snapshot in the destination's file system, in which
case it can be specified as the last component of the name (the # or
@ character and following).

If the incremental target is a clone, the incremental source can be
the origin snapshot, or an earlier snapshot in the origin's
filesystem, or the origin's origin, etc.

-w, --raw
For encrypted datasets, send data exactly as it exists on disk. This
allows backups to be taken even if encryption keys are not currently
loaded. The backup may then be received on an untrusted machine
since that machine will not have the encryption keys to read the
protected data or alter it without being detected. Upon being
received, the dataset will have the same encryption keys as it did on
the send side, although the keylocation property will be defaulted to
prompt if not otherwise provided. For unencrypted datasets, this
flag will be equivalent to -Lec. Note that if you do not use this
flag for sending encrypted datasets, data will be sent unencrypted
and may be re-encrypted with a different encryption key on the
receiving system, which will disable the ability to do a raw send to
that system for incrementals.

zfs send [-Penv] -t receive_resume_token
Creates a send stream which resumes an interrupted receive. The
receive_resume_token is the value of this property on the filesystem or
volume that was being received into. See the documentation for zfs
receive -s for more details.

zfs receive [-Fhnsuv] [-o origin=snapshot] [-o property=value] [-x
property] filesystem|volume|snapshot

zfs receive [-Fhnsuv] [-d|-e] [-o origin=snapshot] [-o property=value] [-x
property] filesystem
Creates a snapshot whose contents are as specified in the stream provided
on standard input. If a full stream is received, then a new file system
is created as well. Streams are created using the zfs send subcommand,
which by default creates a full stream. zfs recv can be used as an alias
for zfs receive.

If an incremental stream is received, then the destination file system
must already exist, and its most recent snapshot must match the
incremental stream's source. For zvols, the destination device link is
destroyed and recreated, which means the zvol cannot be accessed during
the receive operation.

When a snapshot replication package stream that is generated by using the
zfs send -R command is received, any snapshots that do not exist on the
sending location are destroyed by using the zfs destroy -d command.

If -o property=value or -x property is specified, it applies to the
effective value of the property throughout the entire subtree of
replicated datasets. Effective property values will be set ( -o ) or
inherited ( -x ) on the topmost in the replicated subtree. In descendant
datasets, if the property is set by the send stream, it will be
overridden by forcing the property to be inherited from the top-most file
system. Received properties are retained in spite of being overridden
and may be restored with zfs inherit -S. Specifying -o origin=snapshot
is a special case because, even if origin is a read-only property and
cannot be set, it's allowed to receive the send stream as a clone of the
given snapshot.

Raw encrypted send streams (created with zfs send -w ) may only be
received as is, and cannot be re-encrypted, decrypted, or recompressed by
the receive process. Unencrypted streams can be received as encrypted
datasets, either through inheritance or by specifying encryption
parameters with the -o options. Note that the keylocation property
cannot be overridden to prompt during a receive. This is because the
receive process itself is already using stdin for the send stream.
Instead, the property can be overridden after the receive completes.

The added security provided by raw sends adds some restrictions to the
send and receive process. ZFS will not allow a mix of raw receives and
non-raw receives. Specifically, any raw incremental receives that are
attempted after a non-raw receive will fail. Non-raw receives do not
have this restriction and, therefore, are always possible. Because of
this, it is best practice to always use either raw sends for their
security benefits or non-raw sends for their flexibility when working
with encrypted datasets, but not a combination.

The reason for this restriction stems from the inherent restrictions of
the AEAD ciphers that ZFS uses to encrypt data. When using ZFS native
encryption, each block of data is encrypted against a randomly generated
number known as the "initialization vector" (IV), which is stored in the
filesystem metadata. This number is required by the encryption
algorithms whenever the data is to be decrypted. Together, all of the
IVs provided for all of the blocks in a given snapshot are collectively
called an "IV set". When ZFS performs a raw send, the IV set is
transferred from the source to the destination in the send stream. When
ZFS performs a non-raw send, the data is decrypted by the source system
and re-encrypted by the destination system, creating a snapshot with
effectively the same data, but a different IV set. In order for
decryption to work after a raw send, ZFS must ensure that the IV set used
on both the source and destination side match. When an incremental raw
receive is performed on top of an existing snapshot, ZFS will check to
confirm that the "from" snapshot on both the source and destination were
using the same IV set, ensuring the new IV set is consistent.

The name of the snapshot (and file system, if a full stream is received)
that this subcommand creates depends on the argument type and the use of
the -d or -e options.

If the argument is a snapshot name, the specified snapshot is created.
If the argument is a file system or volume name, a snapshot with the same
name as the sent snapshot is created within the specified filesystem or
volume. If neither of the -d or -e options are specified, the provided
target snapshot name is used exactly as provided.

The -d and -e options cause the file system name of the target snapshot
to be determined by appending a portion of the sent snapshot's name to
the specified target filesystem. If the -d option is specified, all but
the first element of the sent snapshot's file system path (usually the
pool name) is used and any required intermediate file systems within the
specified one are created. If the -e option is specified, then only the
last element of the sent snapshot's file system name (i.e. the name of
the source file system itself) is used as the target file system name.

-F Force a rollback of the file system to the most recent snapshot
before performing the receive operation. If receiving an incremental
replication stream (for example, one generated by zfs send -R
[-i|-I]), destroy snapshots and file systems that do not exist on the
sending side.

-d Discard the first element of the sent snapshot's file system name,
using the remaining elements to determine the name of the target file
system for the new snapshot as described in the paragraph above.

-e Discard all but the last element of the sent snapshot's file system
name, using that element to determine the name of the target file
system for the new snapshot as described in the paragraph above.

-h Skip the receive of holds. There is no effect if holds are not sent.

-n Do not actually receive the stream. This can be useful in
conjunction with the -v option to verify the name the receive
operation would use.

-o origin=snapshot
Forces the stream to be received as a clone of the given snapshot.
If the stream is a full send stream, this will create the filesystem
described by the stream as a clone of the specified snapshot. Which
snapshot was specified will not affect the success or failure of the
receive, as long as the snapshot does exist. If the stream is an
incremental send stream, all the normal verification will be
performed.

-o property=value
Sets the specified property as if the command zfs set property=value
was invoked immediately before the receive. When receiving a stream
from zfs send -R, causes the property to be inherited by all
descendant datasets, as though zfs inherit property was run on any
descendant datasets that have this property set on the sending
system.

Any editable property can be set at receive time. Set-once
properties bound to the received data, such as normalization and
casesensitivity, cannot be set at receive time even when the datasets
are newly created by zfs receive. Additionally both settable
properties version and volsize cannot be set at receive time.

The -o option may be specified multiple times, for different
properties. An error results if the same property is specified in
multiple -o or -x options.

The -o option may also be used to override encryption properties upon
initial receive. This allows unencrypted streams to be received as
encrypted datasets. To cause the received dataset (or root dataset
of a recursive stream) to be received as an encryption root, specify
encryption properties in the same manner as is required for zfs
create. For instance:

# zfs send tank/test@snap1 | zfs recv -o encryption=on -o keyformat=passphrase -o keylocation=file:///path/to/keyfile

Note that [-o keylocation=prompt] may not be specified here, since
stdin is already being utilized for the send stream. Once the
receive has completed, you can use zfs set to change this setting
after the fact. Similarly, you can receive a dataset as an encrypted
child by specifying [-x encryption] to force the property to be
inherited. Overriding encryption properties (except for keylocation)
is not possible with raw send streams.

-s If the receive is interrupted, save the partially received state,
rather than deleting it. Interruption may be due to premature
termination of the stream (e.g. due to network failure or failure of
the remote system if the stream is being read over a network
connection), a checksum error in the stream, termination of the zfs
receive process, or unclean shutdown of the system.

The receive can be resumed with a stream generated by zfs send -t
token, where the token is the value of the receive_resume_token
property of the filesystem or volume which is received into.

To use this flag, the storage pool must have the extensible_dataset
feature enabled. See zpool-features(7) for details on ZFS feature
flags.

-u File system that is associated with the received stream is not
mounted.

-v Print verbose information about the stream and the time required to
perform the receive operation.

-x property
Ensures that the effective value of the specified property after the
receive is unaffected by the value of that property in the send
stream (if any), as if the property had been excluded from the send
stream.

If the specified property is not present in the send stream, this
option does nothing.

If a received property needs to be overridden, the effective value
will be set or inherited, depending on whether the property is
inheritable or not.

In the case of an incremental update, -x leaves any existing local
setting or explicit inheritance unchanged.

All -o restrictions (e.g. set-once) apply equally to -x.

zfs receive -A filesystem|volume
Abort an interrupted zfs receive -s, deleting its saved partially
received state.

zfs allow filesystem|volume
Displays permissions that have been delegated on the specified filesystem
or volume. See the other forms of zfs allow for more information.

zfs allow [-dglu] user|group[,user|group]...
perm|@setname[,perm|@setname]... filesystem|volume

zfs allow [-dl] -e|everyone perm|@setname[,perm|@setname]...
filesystem|volume
Delegates ZFS administration permission for the file systems to non-
privileged users.

-d Allow only for the descendent file systems.

-e|everyone
Specifies that the permissions be delegated to everyone.

-g group[,group]...
Explicitly specify that permissions are delegated to the group.

-l Allow "locally" only for the specified file system.

-u user[,user]...
Explicitly specify that permissions are delegated to the user.

user|group[,user|group]...
Specifies to whom the permissions are delegated. Multiple entities
can be specified as a comma-separated list. If neither of the -gu
options are specified, then the argument is interpreted
preferentially as the keyword everyone, then as a user name, and
lastly as a group name. To specify a user or group named "everyone",
use the -g or -u options. To specify a group with the same name as a
user, use the -g options.

perm|@setname[,perm|@setname]...
The permissions to delegate. Multiple permissions may be specified
as a comma-separated list. Permission names are the same as ZFS
subcommand and property names. See the property list below.
Property set names, which begin with @, may be specified. See the -s
form below for details.

If neither of the -dl options are specified, or both are, then the
permissions are allowed for the file system or volume, and all of its
descendents.

Permissions are generally the ability to use a ZFS subcommand or change a
ZFS property. The following permissions are available:

NAME TYPE NOTES
allow subcommand Must also have the permission that is
being allowed
clone subcommand Must also have the 'create' ability and
'mount' ability in the origin file system
create subcommand Must also have the 'mount' ability
destroy subcommand Must also have the 'mount' ability
diff subcommand Allows lookup of paths within a dataset
given an object number, and the ability
to create snapshots necessary to
'zfs diff'.
load-key subcommand Allows loading and unloading of encryption key
(see 'zfs load-key' and 'zfs unload-key').
change-key subcommand Allows changing an encryption key via
'zfs change-key'.
mount subcommand Allows mount/umount of ZFS datasets
promote subcommand Must also have the 'mount' and 'promote'
ability in the origin file system
receive subcommand Must also have the 'mount' and 'create'
ability
rename subcommand Must also have the 'mount' and 'create'
ability in the new parent
rollback subcommand Must also have the 'mount' ability
send subcommand
share subcommand Allows sharing file systems over NFS
or SMB protocols
snapshot subcommand Must also have the 'mount' ability

groupquota other Allows accessing any groupquota@...
property
groupused other Allows reading any groupused@... property
userprop other Allows changing any user property
userquota other Allows accessing any userquota@...
property
userused other Allows reading any userused@... property
projectobjquota other Allows accessing any projectobjquota@...
property
projectquota other Allows accessing any projectquota@... property
projectobjused other Allows reading any projectobjused@... property
projectused other Allows reading any projectused@... property

aclinherit property
aclmode property
atime property
canmount property
casesensitivity property
checksum property
compression property
copies property
devices property
exec property
filesystem_limit property
mountpoint property
nbmand property
normalization property
primarycache property
quota property
readonly property
recordsize property
refquota property
refreservation property
reservation property
secondarycache property
setuid property
sharenfs property
sharesmb property
snapdir property
snapshot_limit property
utf8only property
version property
volblocksize property
volsize property
vscan property
xattr property
zoned property

zfs allow -c perm|@setname[,perm|@setname]... filesystem|volume
Sets "create time" permissions. These permissions are granted (locally)
to the creator of any newly-created descendent file system.

zfs allow -s @setname perm|@setname[,perm|@setname]... filesystem|volume
Defines or adds permissions to a permission set. The set can be used by
other zfs allow commands for the specified file system and its
descendents. Sets are evaluated dynamically, so changes to a set are
immediately reflected. Permission sets follow the same naming
restrictions as ZFS file systems, but the name must begin with @, and can
be no more than 64 characters long.

zfs unallow [-dglru] user|group[,user|group]...
[perm|@setname[,perm|@setname]...] filesystem|volume

zfs unallow [-dlr] -e|everyone [perm|@setname[,perm|@setname]...]
filesystem|volume

zfs unallow [-r] -c [perm|@setname[,perm|@setname]...] filesystem|volume
Removes permissions that were granted with the zfs allow command. No
permissions are explicitly denied, so other permissions granted are still
in effect. For example, if the permission is granted by an ancestor. If
no permissions are specified, then all permissions for the specified
user, group, or everyone are removed. Specifying everyone (or using the
-e option) only removes the permissions that were granted to everyone,
not all permissions for every user and group. See the zfs allow command
for a description of the -ldugec options.

-r Recursively remove the permissions from this file system and all
descendents.

zfs unallow [-r] -s @setname [perm|@setname[,perm|@setname]...]
filesystem|volume
Removes permissions from a permission set. If no permissions are
specified, then all permissions are removed, thus removing the set
entirely.

zfs hold [-r] tag snapshot...
Adds a single reference, named with the tag argument, to the specified
snapshot or snapshots. Each snapshot has its own tag namespace, and tags
must be unique within that space.

If a hold exists on a snapshot, attempts to destroy that snapshot by
using the zfs destroy command return EBUSY.

-r Specifies that a hold with the given tag is applied recursively to
the snapshots of all descendent file systems.

zfs holds [-r] snapshot...
Lists all existing user references for the given snapshot or snapshots.

-r Lists the holds that are set on the named descendent snapshots, in
addition to listing the holds on the named snapshot.

zfs release [-r] tag snapshot...
Removes a single reference, named with the tag argument, from the
specified snapshot or snapshots. The tag must already exist for each
snapshot. If a hold exists on a snapshot, attempts to destroy that
snapshot by using the zfs destroy command return EBUSY.

-r Recursively releases a hold with the given tag on the snapshots of
all descendent file systems.

zfs diff [-FHt] snapshot snapshot|filesystem
Display the difference between a snapshot of a given filesystem and
another snapshot of that filesystem from a later time or the current
contents of the filesystem. The first column is a character indicating
the type of change, the other columns indicate pathname, new pathname (in
case of rename), change in link count, and optionally file type and/or
change time. The types of change are:

- The path has been removed
+ The path has been created
M The path has been modified
R The path has been renamed

-F Display an indication of the type of file, in a manner similar to the
- option of ls(1).

B Block device
C Character device
/ Directory
> Door
| Named pipe
@ Symbolic link
P Event port
= Socket
F Regular file

-H Give more parsable tab-separated output, without header lines and
without arrows.

-t Display the path's inode change time as the first column of output.

zfs program [-jn] [-t timeout] [-m memory_limit] pool script [arg1 ...]
Executes script as a ZFS channel program on pool. The ZFS channel
program interface allows ZFS administrative operations to be run
programmatically via a Lua script. The entire script is executed
atomically, with no other administrative operations taking effect
concurrently. A library of ZFS calls is made available to channel
program scripts. Channel programs may only be run with root privileges.

For full documentation of the ZFS channel program interface, see the
manual page for zfs-program(8).

-j
Display channel program output in JSON format. When this flag is
specified and standard output is empty - channel program encountered an
error. The details of such an error will be printed to standard error
in plain text.

-n
Executes a read-only channel program, which runs faster. The program
cannot change on-disk state by calling functions from the zfs.sync
submodule. The program can be used to gather information such as
properties and determining if changes would succeed (zfs.check.*).
Without this flag, all pending changes must be synced to disk before a
channel program can complete.

-t timeout
Execution time limit, in milliseconds. If a channel program executes
for longer than the provided timeout, it will be stopped and an error
will be returned. The default timeout is 1000 ms, and can be set to a
maximum of 10000 ms.

-m memory-limit
Memory limit, in bytes. If a channel program attempts to allocate more
memory than the given limit, it will be stopped and an error returned.
The default memory limit is 10 MB, and can be set to a maximum of 100
MB.

All remaining argument strings are passed directly to the channel
program as arguments. See zfs-program(8) for more information.

zfs load-key [-nr] [-L keylocation] -a|filesystem
Use keylocation instead of the keylocation property. This will not
change the value of the property on the dataset. Note that if used with
either -r or -a keylocation may only be given as prompt.

-a Loads the keys for all encryption roots in all imported pools.

-n Do a dry-run load-key. This will cause zfs to simply check that
the provided key is correct. This command may be run even if the
key is already loaded.

-r Recursively loads the keys for the specified filesystem and all
descendent encryption roots.

zfs unload-key [-r] -a|filesystem
Unloads a key from ZFS, removing the ability to access the dataset and
all of its children that inherit the encryption property. This requires
that the dataset is not currently open or mounted. Once the key is
unloaded the keystatus property will be set to unavailable.

-a Unloads the keys for all encryption roots in all imported pools.

-r Recursively unloads the keys for the specified filesystem and all
descendent encryption roots.

zfs change-key [-il] [-o keylocation=value] [-o keyformat=value] [-o
pbkdf2iters=value] filesystem
Allows a user to change the encryption key used to access a dataset.
This command requires that the existing key for the dataset is already
loaded into ZFS. This command may also be used to change the
keylocation, keyformat, and pbkdf2iters properties as needed. If the
dataset was not previously an encryption root it will become one.
Alternatively, the -i flag may be provided to cause an encryption root to
inherit the parent's key instead.

-i Indicates that ZFS should make filesystem inherit the key of its
parent. Note that this command can only be run on an encryption
root that has an encrypted parent.

-l Ensures the key is loaded before attempting to change the key.
This is effectively equivalent to "zfs load-key filesystem; zfs
change-key filesystem".

-o property=value
Allows the user to set encryption key properties () keyformat,
keylocation, and pbkdf2iters while changing the key. This is the
only way to alter keyformat and pbkdf2iters after the dataset has
been created.

EXIT STATUS

The zfs utility exits 0 on success, 1 if an error occurs, and 2 if invalid
command line options were specified.

EXAMPLES

Example 1 Creating a ZFS File System Hierarchy
The following commands create a file system named pool/home and a file
system named pool/home/bob. The mount point /export/home is set for the
parent file system, and is automatically inherited by the child file
system.

# zfs create pool/home
# zfs set mountpoint=/export/home pool/home
# zfs create pool/home/bob

Example 2 Creating a ZFS Snapshot
The following command creates a snapshot named yesterday. This snapshot
is mounted on demand in the .zfs/snapshot directory at the root of the
pool/home/bob file system.

# zfs snapshot pool/home/bob@yesterday

Example 3 Creating and Destroying Multiple Snapshots
The following command creates snapshots named yesterday of pool/home and
all of its descendent file systems. Each snapshot is mounted on demand
in the .zfs/snapshot directory at the root of its file system. The
second command destroys the newly created snapshots.

# zfs snapshot -r pool/home@yesterday
# zfs destroy -r pool/home@yesterday

Example 4 Disabling and Enabling File System Compression
The following command disables the compression property for all file
systems under pool/home. The next command explicitly enables compression
for pool/home/anne.

# zfs set compression=off pool/home
# zfs set compression=on pool/home/anne

Example 5 Listing ZFS Datasets
The following command lists all active file systems and volumes in the
system. Snapshots are displayed if the listsnaps property is on. The
default is off. See zpool(8) for more information on pool properties.

# zfs list
NAME USED AVAIL REFER MOUNTPOINT
pool 450K 457G 18K /pool
pool/home 315K 457G 21K /export/home
pool/home/anne 18K 457G 18K /export/home/anne
pool/home/bob 276K 457G 276K /export/home/bob

Example 6 Setting a Quota on a ZFS File System
The following command sets a quota of 50 Gbytes for pool/home/bob.

# zfs set quota=50G pool/home/bob

Example 7 Listing ZFS Properties
The following command lists all properties for pool/home/bob.

# zfs get all pool/home/bob
NAME PROPERTY VALUE SOURCE
pool/home/bob type filesystem -
pool/home/bob creation Tue Jul 21 15:53 2009 -
pool/home/bob used 21K -
pool/home/bob available 20.0G -
pool/home/bob referenced 21K -
pool/home/bob compressratio 1.00x -
pool/home/bob mounted yes -
pool/home/bob quota 20G local
pool/home/bob reservation none default
pool/home/bob recordsize 128K default
pool/home/bob mountpoint /pool/home/bob default
pool/home/bob sharenfs off default
pool/home/bob checksum on default
pool/home/bob compression on local
pool/home/bob atime on default
pool/home/bob devices on default
pool/home/bob exec on default
pool/home/bob setuid on default
pool/home/bob readonly off default
pool/home/bob zoned off default
pool/home/bob snapdir hidden default
pool/home/bob aclmode discard default
pool/home/bob aclinherit restricted default
pool/home/bob canmount on default
pool/home/bob xattr on default
pool/home/bob copies 1 default
pool/home/bob version 4 -
pool/home/bob utf8only off -
pool/home/bob normalization none -
pool/home/bob casesensitivity sensitive -
pool/home/bob vscan off default
pool/home/bob nbmand off default
pool/home/bob sharesmb off default
pool/home/bob refquota none default
pool/home/bob refreservation none default
pool/home/bob primarycache all default
pool/home/bob secondarycache all default
pool/home/bob usedbysnapshots 0 -
pool/home/bob usedbydataset 21K -
pool/home/bob usedbychildren 0 -
pool/home/bob usedbyrefreservation 0 -

The following command gets a single property value.

# zfs get -H -o value compression pool/home/bob
on
The following command lists all properties with local settings for
pool/home/bob.

# zfs get -r -s local -o name,property,value all pool/home/bob
NAME PROPERTY VALUE
pool/home/bob quota 20G
pool/home/bob compression on

Example 8 Rolling Back a ZFS File System
The following command reverts the contents of pool/home/anne to the
snapshot named yesterday, deleting all intermediate snapshots.

# zfs rollback -r pool/home/anne@yesterday

Example 9 Creating a ZFS Clone
The following command creates a writable file system whose initial
contents are the same as pool/home/bob@yesterday.

# zfs clone pool/home/bob@yesterday pool/clone

Example 10 Promoting a ZFS Clone
The following commands illustrate how to test out changes to a file
system, and then replace the original file system with the changed one,
using clones, clone promotion, and renaming:

# zfs create pool/project/production
populate /pool/project/production with data
# zfs snapshot pool/project/production@today
# zfs clone pool/project/production@today pool/project/beta
make changes to /pool/project/beta and test them
# zfs promote pool/project/beta
# zfs rename pool/project/production pool/project/legacy
# zfs rename pool/project/beta pool/project/production
once the legacy version is no longer needed, it can be destroyed
# zfs destroy pool/project/legacy

Example 11 Inheriting ZFS Properties
The following command causes pool/home/bob and pool/home/anne to inherit
the checksum property from their parent.

# zfs inherit checksum pool/home/bob pool/home/anne

Example 12 Remotely Replicating ZFS Data
The following commands send a full stream and then an incremental stream
to a remote machine, restoring them into poolB/received/fs@a and
poolB/received/fs@b, respectively. poolB must contain the file system
poolB/received, and must not initially contain poolB/received/fs.

# zfs send pool/fs@a | \
ssh host zfs receive poolB/received/fs@a
# zfs send -i a pool/fs@b | \
ssh host zfs receive poolB/received/fs

Example 13 Using the zfs receive -d Option
The following command sends a full stream of poolA/fsA/fsB@snap to a
remote machine, receiving it into poolB/received/fsA/fsB@snap. The
fsA/fsB@snap portion of the received snapshot's name is determined from
the name of the sent snapshot. poolB must contain the file system
poolB/received. If poolB/received/fsA does not exist, it is created as
an empty file system.

# zfs send poolA/fsA/fsB@snap | \
ssh host zfs receive -d poolB/received

Example 14 Setting User Properties
The following example sets the user-defined com.example:department
property for a dataset.

# zfs set com.example:department=12345 tank/accounting

Example 15 Performing a Rolling Snapshot
The following example shows how to maintain a history of snapshots with a
consistent naming scheme. To keep a week's worth of snapshots, the user
destroys the oldest snapshot, renames the remaining snapshots, and then
creates a new snapshot, as follows:

# zfs destroy -r pool/users@7daysago
# zfs rename -r pool/users@6daysago @7daysago
# zfs rename -r pool/users@5daysago @6daysago
# zfs rename -r pool/users@4daysago @5daysago
# zfs rename -r pool/users@3daysago @4daysago
# zfs rename -r pool/users@2daysago @3daysago
# zfs rename -r pool/users@yesterday @2daysago
# zfs rename -r pool/users@today @yesterday
# zfs snapshot -r pool/users@today

Example 16 Setting sharenfs Property Options on a ZFS File System
The following commands show how to set sharenfs property options to
enable rw access for a set of IP addresses and to enable root access for
system neo on the tank/home file system.

# zfs set sharenfs='rw=@123.123.0.0/16,root=neo' tank/home

If you are using DNS for host name resolution, specify the fully
qualified hostname.

Example 17 Delegating ZFS Administration Permissions on a ZFS Dataset
The following example shows how to set permissions so that user cindys
can create, destroy, mount, and take snapshots on tank/cindys. The
permissions on tank/cindys are also displayed.

# zfs allow cindys create,destroy,mount,snapshot tank/cindys
# zfs allow tank/cindys
---- Permissions on tank/cindys --------------------------------------
Local+Descendent permissions:
user cindys create,destroy,mount,snapshot

Because the tank/cindys mount point permission is set to 755 by default,
user cindys will be unable to mount file systems under tank/cindys. Add
an ACE similar to the following syntax to provide mount point access:

# chmod A+user:cindys:add_subdirectory:allow /tank/cindys

Example 18 Delegating Create Time Permissions on a ZFS Dataset
The following example shows how to grant anyone in the group staff to
create file systems in tank/users. This syntax also allows staff members
to destroy their own file systems, but not destroy anyone else's file
system. The permissions on tank/users are also displayed.

# zfs allow staff create,mount tank/users
# zfs allow -c destroy tank/users
# zfs allow tank/users
---- Permissions on tank/users ---------------------------------------
Permission sets:
destroy
Local+Descendent permissions:
group staff create,mount

Example 19 Defining and Granting a Permission Set on a ZFS Dataset
The following example shows how to define and grant a permission set on
the tank/users file system. The permissions on tank/users are also
displayed.

# zfs allow -s @pset create,destroy,snapshot,mount tank/users
# zfs allow staff @pset tank/users
# zfs allow tank/users
---- Permissions on tank/users ---------------------------------------
Permission sets:
@pset create,destroy,mount,snapshot
Local+Descendent permissions:
group staff @pset

Example 20 Delegating Property Permissions on a ZFS Dataset
The following example shows to grant the ability to set quotas and
reservations on the users/home file system. The permissions on
users/home are also displayed.

# zfs allow cindys quota,reservation users/home
# zfs allow users/home
---- Permissions on users/home ---------------------------------------
Local+Descendent permissions:
user cindys quota,reservation
cindys% zfs set quota=10G users/home/marks
cindys% zfs get quota users/home/marks
NAME PROPERTY VALUE SOURCE
users/home/marks quota 10G local

Example 21 Removing ZFS Delegated Permissions on a ZFS Dataset
The following example shows how to remove the snapshot permission from
the staff group on the tank/users file system. The permissions on
tank/users are also displayed.

# zfs unallow staff snapshot tank/users
# zfs allow tank/users
---- Permissions on tank/users ---------------------------------------
Permission sets:
@pset create,destroy,mount,snapshot
Local+Descendent permissions:
group staff @pset

Example 22 Showing the differences between a snapshot and a ZFS Dataset
The following example shows how to see what has changed between a prior
snapshot of a ZFS dataset and its current state. The -F option is used
to indicate type information for the files affected.

# zfs diff -F tank/test@before tank/test
M / /tank/test/
M F /tank/test/linked (+1)
R F /tank/test/oldname -> /tank/test/newname
- F /tank/test/deleted
+ F /tank/test/created
M F /tank/test/modified

INTERFACE STABILITY

Committed.

SEE ALSO

gzip(1), ssh(1), chmod(2), stat(2), write(2), fsync(3C), dfstab(5), acl(7),
attributes(7), mount(8), share(8), sharemgr(8), unshare(8), zfs-program(8),
zonecfg(8), zpool(8)

illumos November 3, 2023 illumos