FORMAT(8) Maintenance Commands and Procedures FORMAT(8)
NAME
format - disk partitioning and maintenance utility
SYNOPSIS
format [
-f command-file] [
-l log-file] [
-x data-file]
[
-d disk-name] [
-t disk-type] [
-p partition-name]
[
-s] [
-m] [
-M] [
-e] [
disk-list]
DESCRIPTION
format enables you to format, label, repair, and analyze disks on your
system. Unlike previous disk maintenance programs,
format runs under
SunOS. Because there are limitations to what can be done to the system
disk while the system is running,
format is also supported within the
memory-resident system environment. For most applications, however,
running
format under SunOS is the more convenient approach.
format first uses the disk list defined in
data-file if the
-x option is
used.
format then checks for the
FORMAT_PATH environment variable, a
colon-separated list of filenames and/or directories. In the case of a
directory,
format searches for a file named
format.dat in that directory;
a filename should be an absolute pathname, and is used without change.
format adds all disk and partition definitions in each specified file to
the working set. Multiple identical definitions are silently ignored. If
FORMAT_PATH is not set, the path defaults to
/etc/format.dat.
disk-list is a list of disks in the form
c?t?d? or
/dev/rdsk/c?t?d?s?.
With the latter form, shell wildcard specifications are supported. For
example, specifying
/dev/rdsk/c2* causes
format to work on all drives
connected to controller
c2 only. If no
disk-list is specified,
format lists all the disks present in the system that can be administered by
format.
Removable media devices are listed only when users execute
format in
expert mode (option
-e). This feature is provided for backward
compatibility. Use
rmformat(1) for rewritable removable media devices.
OPTIONS
The following options are supported:
-d disk-name Specify which disk should be made current upon entry
into the program. The disk is specified by its
logical name (for instance,
-d c0t1d0). This can
also be accomplished by specifying a single disk in
the disk list.
-e Enable
SCSI expert menu. Note this option is not
recommended for casual use.
-f command-file Take command input from
command-file rather than the
standard input. The file must contain commands that
appear just as they would if they had been entered
from the keyboard. With this option,
format does not
issue
continue? prompts; there is no need to specify
y(es) or n(o) answers in the
command-file. In non-
interactive mode,
format does not initially expect
the input of a disk selection number. The user must
specify the current working disk with the
-d disk- name option when format is invoked, or specify
disk and the disk selection number in the
command-file.
-l log-file Log a transcript of the
format session to the
indicated
log-file, including the standard input,
the standard output and the standard error.
-m Enable extended messages. Provides more detailed
information in the event of an error.
-M Enable extended and diagnostic messages. Provides
extensive information on the state of a
SCSI device's mode pages, during formatting.
-p partition-name Specify the partition table for the disk which is
current upon entry into the program. The table is
specified by its name as defined in the data file.
This option can be used only if a disk is being made
current, and its type is either specified or
available from the disk label.
-s Silent. Suppress all of the standard output. Error
messages are still displayed. This is generally used
in conjunction with the
-f option.
-t disk-type Specify the type of disk which is current upon entry
into the program. A disk's type is specified by name
in the data file. This option can only be used if a
disk is being made current as described above.
-x data-file Use the list of disks contained in
data-file.
USAGE
When you invoke format with no options or with the
-e,
-l,
-m,
-M, or
-s options, the program displays a numbered list of available disks and
prompts you to specify a disk by list number. If the machine has more
than 10 disks, press SPACE to see the next screenful of disks.
You can specify a disk by list number even if the disk is not displayed
in the current screenful. For example, if the current screen shows disks
11-20, you can enter
25 to specify the twenty-fifth disk on the list. If
you enter a number for a disk that is not currently displayed,
format prompts you to verify your selection. If you enter a number from the
displayed list,
format silently accepts your selection.
After you specify a disk,
format displays its main menu. This menu
enables you to perform the following tasks:
analyze Run read, write, compare tests, and data purge. The data
purge function implements the National Computer Security
Center Guide to Understanding Data Remnance (
NCSC-TG-025 version 2) Overwriting Algorithm. See NOTES.
backup Search for backup labels.
cache Enable, disable, and query the state of the write cache and
read cache. This menu item only appears when
format is
invoked with the
-e option, and is only supported on
SCSI devices.
current Display the device name, the disk geometry, and the pathname
to the disk device.
defect Retrieve and print defect lists. This option is supported
only on
SCSI devices.
IDE disks perform automatic defect
management. Upon using the
defect option on an
IDE disk, you
receive the message:
Controller does not support defect management
or disk supports automatic defect management.
disk Choose the disk that will be used in subsequent operations
(known as the current disk.)
fdisk Run the
fdisk(8) program to create a
fdisk partition for
Solaris software (x86 based systems only).
format Format and verify the current disk. This option is supported
only on
SCSI devices.
IDE disks are pre-formatted by the
manufacturer. Upon using the
format option on an
IDE disk,
you receive the message:
Cannot format this drive. Please use your
manufacturer-supplied formatting utility.
inquiry Display the vendor, product name, and revision level of the
current drive.
label Write a new label to the current disk.
partition Create and modify slices.
quit Exit the format menu.
repair Repair a specific block on the disk.
save Save new disk and slice information.
type Select (define) a disk type.
verify Read and display labels. Print information such as the
number of cylinders, alternate cylinders, heads, sectors,
and the partition table.
volname Label the disk with a new eight character volume name.
ENVIRONMENT VARIABLES
FORMAT_PATH a colon-separated list of filenames and/or directories of
disk and partition definitions. If a directory is
specified,
format searches for the file
format.dat in that
directory.
FILES
/etc/format.dat default data file
SEE ALSO
rmformat(1),
sd(4D),
format.dat(5),
attributes(7),
fmthard(8),
prtvtoc(8) x86 Only fdisk(8)WARNINGS
When the
format function is selected to format the Maxtor 207MB disk, the
following message displays:
Mode sense
page(4) reports rpm value as 0, adjusting it to 3600
This is a drive bug that may also occur with older third party drives.
The above message is not an error; the drive will still function
correctly.
Cylinder 0 contains the partition table (disk label), which can be
overwritten if used in a raw disk partition by third party software.
format supports writing
EFI-compliant disk labels in order to support
disks or
LUNs with capacities greater than one terabyte. However, care
should be exercised since many software components, such as filesystems
and volume managers, are still restricted to capacities of one terabyte
or less. See the
System Administration Guide: Basic Administration for
additional information.
By default, on an unlabeled disk, EFI labels will be written on disks
larger than 2 TB. When
format is invoked with the
-e option, on writing
the label, the label type can be chosen. Booting is not currently
supported on a disk with an EFI label.
NOTES
format provides a help facility you can use whenever format is expecting
input. You can request help about what information is expected by simply
entering a question mark (
?) and
format prints a brief description of
what type of input is needed. If you enter a
? at the menu prompt, a list
of available commands is displayed.
For
SCSI disks, formatting is done with both Primary and Grown defects
list by default. However, if only Primary list is extracted in defect
menu before formatting, formatting will be done with Primary list only.
Changing the state of the caches is only supported on
SCSI devices, and
not all
SCSI devices support changing or saving the state of the caches.
The
NCSC-TG-025 algorithm for overwriting meets the
DoD 5200.28-M (
ADP Security Manual) Eraser Procedures specification. The
NIST Guidelines for
Media Sanitization (
NIST SP 800-88) also reference this algorithm.
August 29, 2021
FORMAT(8)