Solaris Transition Guide

Device Naming Conventions

Device naming conventions have changed between the SunOS release 4 and SunOS release 5.7 platforms. In addition, the /dev directory, which contains the special device names, has been changed from a flat directory to a hierarchical one, with a separate subdirectory for each category of device. For example, the location of disk device files is /dev/dsk, while raw disks are located in /dev/rdsk.

SunOS release 5.7 commands that take device names as arguments must use the SunOS release 5.7 device naming conventions. However, you can still use and recognize the SunOS release 4 device names if you install the SunOS/BSD Source Compatibility Package. See Source Compatibility Guide for additional information.

Convention for Disks

The disk partition slice numbers (0 through 7) correspond to partitions a through h of previous SunOS releases.

Note -

Most SCSI disks have embedded controllers. This means that the drive number will always be 0 but the target number varies. For example, if an external disk drive has its rear switch set to 2, the device name for the first slice is /dev/dsk/c0t2d0s0, not /dev/dsk/c0t0d2s0.

Because the names for SCSI targets 0 and 3 were reversed on some sun4c systems, device naming can be confusing. Under the SunOS 4.1.x software, SCSI target 3 was called sd0(), but it is now properly named c0t3d0. SCSI target 0 was called sd3(), but it is now named c0t0d0. Other SCSI disk names translate normally. For example, in the SunOS release 5.7 software, sd2a is c0t2d0s0 and sd2b is c0t2d0s1.

Convention for Tape Drives


Table 7-1 provides some examples that compare the SunOS release 4 and SunOS release 5.7 device naming conventions.

Table 7-1 SunOS release 4 and SunOS Release 5.7 Device Names

Device Description 

SunOS Release 4 Device Name 

SunOS Release 5.7 Device Name

Disk devices









Magnetic tape devices 






CD-ROM device