HP-UX System Administrator's Guide: Overview

/dev/disk/disk15_p3
/dev/rdisk/disk7_p1
The following directories still exist in HP-UX 11i version 3 for backwards compatibility.
They contain the legacy device special files defining the physical drives on a server (the
legacy form):
/dev/dsk
Contains legacy device special files for block mode access to physical
disk devices on a server.
/dev/rdsk
Contains legacy device special files for character mode access to physical
disk devices on a server.
Within these directories, files have names in the format “c#t#d#” (where c# represents
the controller instance number, t# represents the SCSI target number, and d# represents
the SCSI LUN number).
Examples:
/dev/dsk/c3t7d0
/dev/rdsk/c3t15d5
With legacy device special files that are associated with disks an optional part of the
filename can represent disk partition numbers. By convention, in the absence of this
optional part of the device file name the name represents an entire disk. This optional
part expands the format of the name to be c#t#d#s# (where s# represents the partition
number, tape density, or other information).
Examples:
/dev/dsk/c3t7d0s3
/dev/rdsk/c3t15d7s1
NOTE: You can use both legacy and persistent device special files simultaneously
but to gain the many benefits of persistent device special files, you need to use those.
For example, using legacy device special files you can only define and address up to
256 external buses on a server. If you have more than 256 you will need to use persistent
device special files to access the devices beyond the 256 address boundary.
For Additional Information on Naming Device Special Files
Additional information on naming device special files is located in the following
manpages:
• autochanger(7)
• disk(7)
• intro(7)
• mt(7)
Storage on HP-UX 65