Re: Help - I can't create device files.

From: Tim Bradshaw (tfb_at_cley.com)
Date: 10/27/03 

Date: Mon, 27 Oct 2003 11:20:25 +0000

* David Kirkby wrote:

> The original (small) problem was the external disks would not mount.
> For reasons I can't work out, following a boot -r, the /dev/dsk/c3*
> device files had been removed and in their place were files which
> appeared to be on controller #5 (/dev/dsk/c5*) - which is a bit odd
> given I only have 4 SCSI controllers - two on the motherboard, plus a
> dual SCSI card.

There is magic here which is very fiddly to get
right. /etc/path_to_inst is part of it, but not all. Somewhere, and I
forget where, the system remembers something about all the
controllers it thinks its ever seen, in order that it doesn't reuse
a number when a controller is temporarily unavailable.

The particular problem we had was that we have a SSA which we use for
developing VxVM courses. I changed the unique ID of it to be
something `more suitable', and when I did a boot -r (or devfsadm), the
system ended up such that there was c0 (internal scsi), c1 (the `old'
SSA) and c2 (the `new' one). I spent really a very long time trying
to find out where it cached the information about the existence of the
old one so I could make it forget about it, and I wish I could
remember where it was! I'm fairly sure (very sure in fact) that it's
not /etc/path_to_inst, or not only that, and I don't think it's
existing device files either. I did, eventually, work out what the
problem was, but I stupidly didn't record it anywhere I can now find
it.

--tim