Hello all,
I'm
building a new NBU 6.5 environment on RedHat...
[root@<>dev]# uname -a
Linux <>2 2.6.9-55.ELsmp #1 SMP
Fri Apr 20 16:36:54 EDT 2007 x86_64 x86_64 x86_64
GNU/Linux
and
am trying to wrap my head around the FC-SCSI tape device
configuration. I have seen/heard mention that udev rules should be
create to ensure that persistent naming occurs in the event that the server
gets rebooted, SAN changes are made, new devices are added,
etc
The
way I understand things, the following is the method to get things working on
the server side:
1)
Kernel detects tape scsi devices and creates /dev/nst## device files (and
/dev/st## device files)
ie: /dev/nst1
2)
Links are created via the default udevrules , create "tape" device
symlinks.
ie: tape81 -> nst23a
3)
Run "/dev/MAKEDEV sg" to create the sg links that Netbackup needs to
populate the device database
Question here: does the MAKEDEV command look
for /dev/nst devices? Or is it based on the "tape#" symlinks described
above?
If
the answer is that is uses the symlinks, then I think I understand how the
udev rules would be used (scsi_id -g -u -s <nst device> used
to get the scsi inquiry string, create a rules so that the result of that
inquiry always creates the same tape#). If not, could someone enlighten
me?
Cheers,
Jon