[Info-vax] Unpleasant Disk Shadowing Surprise

[tadamsmar]

On Oct 11, 10:53 am, tadamsmar <tadams... at yahoo.com> wrote:
> This is VMS 7.3-2 on a DS10.  I am at V19.0 on patch updates (applied
> in July 2009)
>
> Our real-time application halted for more than 3 minutes.
>
> After the incident I found here was a disk error on one member of the
> shadow set.
>
> The first indication was whe the application watchdog alarm went off.
>
> According to the console log, more than 30 seconds after the watchdog
> sounded, the shadow set changed state, the offending disk went
> offline, a mount verification started and completed.
>
> Immediately after the mount verification completed, VMS started
> working again.
>
> Looks like the disk system was inaccessible for about 3 minutes and
> any process that tried to use it got
> halted somehow.
>
> Is this to be expected?  We have had VMS and disk shadowing running
> the application for 20 years or so, but I don't know that we have ever
> had a disk error while the watchdog was configured to sound, so we
> might not have noticed the halting and recovery.

Well, I just reseated the SCSI cable on DKA100 an now it all works.

The DS10 SCSI cable does not click in.

If you ever watched a DEC service technician work, the last thing he
does before he puts the cover back on a DS10 is he reaches around
inside and pushes on things.  I use to wonder what he was doing....