>Issue:  We unfortunately lost two disks on a RAID 5 array that contained
>the database, recovery log, and primary diskpools.  Compounding the
>problem the volhist.bak and devconfig.bak files were stored on the same
>disk array (we had a nightly script in place to copy to an AFS location
>but it had been disabled due to maintenance previously).  So, my
>question is, how can I determine which tape volume my database backup
>from yesterday is on?  Is there a way using the interface on the 3494?
>Any other thoughts or suggestions?  I'm currently configuring the
>storage array for use and will need to execute a restore db command
>fairly soon.  Many thanks in advance - I never thought I could have two
>simultaneous disk failures in a RAID 5 array as well as our DR script
>disabled at the same time...

A classic DR procedures failure.
Without the files which definitively record volume usage, you will have
to grope in the dark.  (More on that below.)
In that two disks "failed", might this actually be not a disk failure but
something simpler like a power supply issue which, if itself resolved,
could restore access to intact drives?  Check into just what really is
broken there.

As for working in the dark...  If you know the approximate time period of
when your dbbackup was taken, you can narrow it down to a few tape volumes
and then try each in a db restore: only one tape in a given time period
can be a dbbackup, and the others ordinary data, which db restore should
spit out.
Go to your 3494 operator panel.  Activate Service Mode.  In the Utilities
menu, choose View Logs.  Go into the candidate TRN (transactions) log.
Look for MOUNT_COMPLETE, DEMOUNT_COMPLETE entries in your time period.
The volser is in angle brackets, like <001646001646>, wherein the volser
is 001646.

  Richard Sims, BU