disk(7)

disk -- disk device file

Description

For hardware-related files, the names of the entries are generally derived from names for the hardware, as opposed to the names of the special files themselves. Characteristics of both the hardware device and the corresponding device driver are discussed where applicable.

SCSI and non-SCSI disks

Disk device filenames have either of the two following forms:

/dev/[r]dsk/cCbBtTdDsS

/dev/[r]dsk/cCbBtTdDpP

[r]dsk: /rdsk denotes a raw (character) device; /dsk indicates a block device.
cC: C is the occurrence of the host adapter board or IDE controller in the system (that is, card number). C can range from 0 to 31.
bB: B is the HBA bus number, ranging from 0 to 7 (dependent on the add-on adapter). This is always 0 for IDE disks.
tT: T is the SCSI target controller number (ID). The value of T can range from 0 to 31. The first IDE disk is target 0, and the second is target 1.
dD: D is the logical unit number of the disk device, ranging from 0 to 31. This is always 0 for IDE disks.
sS: S is the disk slice number, ranging from 0 to b7 (hex).
pP: P is the fdisk(1M) partition number. P can range from 0 to 4, to specify an entry in the fdisk partition table. The p0 node corresponds to the whole disk, the p1 to p4 nodes correspond to partitions as they are displayed by the fdisk command.

References

fdisk(1M), sdi(7)