Determine Node Names for Drives and Autochanger

First, we need to determine the unique device “by-id” nodes that udev has assigned to the tape drives and the tape library’s Autochanger device.

In a shell prompt:

# ls -la /dev/tape/by-id
total 0
drwxr-xr-x 2 root root 220 Apr 14 13:00 .
drwxr-xr-x 4 root root  80 Apr 14 13:00 ..
lrwxrwxrwx 1 root root   9 Apr 14 13:00 scsi-350223344ab000100 -> ../../st0
lrwxrwxrwx 1 root root  10 Apr 14 13:00 scsi-350223344ab000100-nst -> ../../nst0  <-----
lrwxrwxrwx 1 root root   9 Apr 14 13:00 scsi-350223344ab000200 -> ../../st1
lrwxrwxrwx 1 root root  10 Apr 14 13:00 scsi-350223344ab000200-nst -> ../../nst1
lrwxrwxrwx 1 root root   9 Apr 14 13:00 scsi-350223344ab000300 -> ../../st2
lrwxrwxrwx 1 root root  10 Apr 14 13:00 scsi-350223344ab000300-nst -> ../../nst2
lrwxrwxrwx 1 root root   9 Apr 14 13:00 scsi-350223344ab000400 -> ../../st3
lrwxrwxrwx 1 root root  10 Apr 14 13:00 scsi-350223344ab000400-nst -> ../../nst3
lrwxrwxrwx 1 root root   9 Apr 14 13:00 scsi-SSTK_L700_XYZZY_A -> ../../sg7       <-----

We are interested in the longer “by-id” device node names which point to our “/dev/nstX” (non-rewind) tape devices.

For the tape drive, we will use the unique “by-id” node name “/dev/tape/by-id/scsi-350223344ab000100-nst” instead of “/dev/nst0” in the configuration.

If the tape library has more than one drive in it, as in the example above, make sure to note the correct “by-id” name of each tape drive, they will be needed later.

In the example output above, there is also a “by-id” device which points to “/dev/sg7”. This is the library’s autochanger device node, and we will use its “by-id” name “/dev/tape/by-id/scsi-SSTK_L700_XYZZY_A” in the configurations.

Throughout the rest of this document, these two “by-id” device node names will be used. Be sure to use the correct device nodes identified on your specific system, and not the device nodes in this document.