"Checkin" is sort of a primitive brain stem function that isn't well
integrated into the other tape management parts of ADSM.  It isn't
multi-threaded, only uses one drive at a time.  I think if you dig around in
the manuals, the Label Libvolume (which is also doing a checkin) doc even
says that it won't work unless there is a tape drive free.

Why, I don't know.  Maybe with enough complaints, we could get the
developers to consider improving this function in future releases....


===============================================================
Wanda Prather
Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think."
              - Scott Adams/Dilbert
===============================================================

> ----------
> From:         Weeks, Debbie[SMTP:debbie AT admin.usf DOT edu]
> Sent:         Tuesday, July 14, 1998 1:04 PM
> To:   ADSM-L AT vm.marist DOT edu
> Subject:      Tape Questions - 3575 Library
>
> ADSM/AIX 3.1.1.2, AIX 4.2.1, 3575 Library
>
> Does anyone know why ADSM will dismount idle tapes (in a 3575 tape
> library) for some processes, but not for others?  It seems if a DB
> backup, migration, or a restore needs a drive it will dismount an idle
> volume.  Yet if I need to check in a volume to satisfy a mount request
> for reclaim, restore, etc. there has to be a drive empty for the task or
> it will fail.  Then I manually (via dismount volume command) dismount
> the volume, and have to run the checkin again.
>
> Also, while we are on the subject of tapes, if ADSM tries to mount a
> tape that has been checked in as scratch, and for some reason the tape
> volume cannot be written to (like maybe an operator checked it in with
> write protect on), why does it continue to attempt the mount of that
> same tape over and over again.  Processes fail even though there are
> other scratch volumes in the library.  So I guess the question would be
>
> 1) How does ADSM select a scratch tape from the library?
> 2) Why does it give a very deceiving error message "unable to open
> drive".
>
> And lastly, ADSM is very smart in some respects, but when it comes to
> tapes it seems the right hand doesn't know what the left is doing.  When
> checking in a tape to satisfy a mount request, why does ADSM have to
> mount the tape, verify the label, put the tape away, then mount the tape
> again for use? (answer for this is probably "because that's how it
> works")
>
> Debbie Weeks
> University of South Florida
> Information Technologies/Technical Support
> *********
> *Debbie AT admin.usf DOT edu
> *(813) 974-6926   *  S/C 574-6926
> Fax(813) 974-3054
>