CMDK(4D) Devices CMDK(4D)
NAME
cmdk - common disk driver
SYNOPSIS
cmdk@
target,
lun : [
partition | slice ]
DESCRIPTION
The
cmdk device driver is a common interface to various disk devices. The
driver supports magnetic fixed disks and magnetic removable disks.
The
cmdk device driver supports three different disk labels: fdisk
partition table, Solaris x86 VTOC and EFI/GPT.
The block-files access the disk using the system's normal buffering
mechanism and are read and written without regard to physical disk
records. There is also a "raw" interface that provides for direct
transmission between the disk and the user's read or write buffer. A
single read or write call usually results in one I/O operation; raw I/O
is therefore considerably more efficient when many bytes are transmitted.
The names of the block files are found in
/dev/dsk. Raw file names are
found in
/dev/rdsk.
I/O requests to the magnetic disk must have an offset and transfer length
that is a multiple of 512 bytes or the driver returns an
EINVAL error.
Slice 0 is normally used for the root file system on a disk, slice 1 as a
paging area (for example, swap), and slice 2 for backing up the entire
fdisk partition for Solaris software. Other slices may be used for
usr file systems or system reserved area.
The fdisk partition 0 is to access the entire disk and is generally used
by the
fdisk(8) program.
FILES
/dev/dsk/cndn[
s|
p]
n block device (IDE)
/dev/rdsk/cndn[
s|
p]
n raw device (IDE)
where:
cn controller
n.
dn lun
n (0-1).
sn UNIX system slice
n (0-15). pn fdisk partition (0-36).
/kernel/drv/cmdk 32-bit kernel module.
/kernel/drv/amd64/cmdk 64-bit kernel module.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|Architecture | x86 |
+---------------+-----------------+
SEE ALSO
lseek(2),
read(2),
write(2),
readdir(3C),
dkio(4I),
scsi(5),
vfstab(5),
attributes(7),
fdisk(8),
mount(8) November 4, 2008
CMDK(4D)