[Info-vax] Unpleasant Disk Shadowing Surprise

[VAXman- at SendSpamHere.ORG]

In article <168e7442-2c78-4dda-8942-6f831d954343 at d28g2000vby.googlegroups.com>, tadamsmar <tadamsmar at yahoo.com> writes:
>On Oct 11, 4:16=A0pm, Kenneth Fairfield <ken.fairfi... at gmail.com> wrote:
>> 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. =A0Errors
>> 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. =A0A single "bad"
>> error on the one disk can hang the whole bus...
>>
>> =A0 =A0 -Ken
>
>I looked at SHOW DEVICE DK.  I now see that I did not read it
>correctly earlier, and I have been confused about some things.
>
>The real sequence of events is that DKA100 went offline and DKA0
>logged an error at almost exactly the same time! Those are my shadow
>set. Hopefully that was a soft error on DKA0 so that my data is not
>compromised, I need to double check that.
>
>I rebooted just before I left work and DKA100 did not even show up
>after the reboot.
>
>I am now thinking that I probably have a bad SCSI cable.  I will
>replace that tomorrow, I think I have one in storage.
>
>We have a single pass HVAC system in our building so the ozone levels
>are close to outdoor levels and this tends to eat the insulation on
>cables.

Where in the world are you that you have cable eating ozone levels?

-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

All your spirit rack abuses, come to haunt you back by day.
All your Byzantine excuses, given time, given you away.