[Info-vax] Unpleasant Disk Shadowing Surprise

[Kenneth Fairfield]

On Tuesday, October 11, 2011 11:53:12 AM UTC-7, tadamsmar wrote:
[...]
> Here is what I find in the error log:
> 
> I had two errors on the pka0: (adaptec aic-7899) at times 7:58:14 and
> 7:58:21

I was more interested in what SHOW DEVICE DK shows
for the members of the shadow set in question.  Errors
on the PK device are not terribly interesting most of
the time (they tend to come in ones and twos at boot
time, etc.).

Of course once you've done a dismount on bad disk,
the count gets reset.

But as others have noted, having both shadow members
on the same scsi bus is problematic.  A single "bad"
error on the one disk can hang the whole bus...

    -Ken