Device Names

Device Names

Device names for disks are filenames that are constructed so that they indicate the type of hardware (disk), type of device access (block or character), type of device, controller number, drive address, and partition number. For example, the block device name for the root partition of a SCSI system disk is /dev/dsk/dks0d1s0. Table 1-4 lists each component of this filename, describes its meaning, and lists other possible values.

Device Name Construction
Device Name Component Purpose Possible Values
dev device files directory dev
dsk subdirectory for hard disk files (think "disk" to remember it) dsk (block device files)
rdsk (character device files; the r stands for "raw," another name for the character device)
dks disk device type dks (SCSI device)
fd (floppy disk)
jag (VME SCSI device, also known as Jaguar disk)
raid (SCSI RAID device)
0 controller number for SCSI: 0-n, where n is system dependent
for VME SCSI (Jaguar): 0-5
for SCSI RAID: 0-14
d1 drive address for SCSI: d1-d7 or d1-d15 (depending upon controller type)
for VME SCSI (Jaguar): d0-d13
for SCSI RAID: dn where n is in the range 0-147 and doesn't end in 8 or 9
s0 partition number (slice number) s0 (root, for the Root filesystem)
s1 (swap)
s2
s3
s4
s5
s6 (usr, for the Usr filesystem)
s7 (entire usable portion of disk, excludes the volume header)
s8, vh (volume header)
s9 (non-SCSI bad block list)
s10, vol (entire disk)
s11
s12
s13
s14
s15 (XFS log)

Device Name Construction
Device Name Component	Purpose	Possible Values
dev	device files directory	dev
dsk	subdirectory for hard disk files (think "disk" to remember it)	dsk (block device files) rdsk (character device files; the r stands for "raw," another name for the character device)
dks	disk device type	dks (SCSI device) fd (floppy disk) jag (VME SCSI device, also known as Jaguar disk) raid (SCSI RAID device)
0	controller number	for SCSI: 0-n, where n is system dependent for VME SCSI (Jaguar): 0-5 for SCSI RAID: 0-14
d1	drive address	for SCSI: d1-d7 or d1-d15 (depending upon controller type) for VME SCSI (Jaguar): d0-d13 for SCSI RAID: dn where n is in the range 0-147 and doesn't end in 8 or 9
s0	partition number (slice number)	s0 (root, for the Root filesystem) s1 (swap) s2 s3 s4 s5 s6 (usr, for the Usr filesystem) s7 (entire usable portion of disk, excludes the volume header) s8, vh (volume header) s9 (non-SCSI bad block list) s10, vol (entire disk) s11 s12 s13 s14 s15 (XFS log)

Some examples of device names and their meanings are:

/dev/dsk/dks0d1s0: The block device file for partition (slice) 0 of the SCSI disk on controller 0 at drive address 1.
/dev/dsk/jag5d13s7: The block device file for partition 7 (the entire disk except volume header) of the Jaguar disk on controller 5 at drive address 13.
/dev/rdsk/dks0d2vh: The character (raw) device for the volume header (partition 8) of the SCSI disk on controller 0 at drive address 2.