Nancy,

The Volume History file is updated any time a  tape volume changes
status.
The STGNEW volumes are any sequential (normally tape) volumes that get
added to a storage pool.
A STGDELETE entry is made any time a storage pool tape is emptied and
returned to scratch.
DBBACKUP volumes are recorded in the VOLHISTORY file as well.
DBBACKUP volumes are retained as long as they exist in the VOLHISTORY
file.

The Volume History file is USED when you are doing a system recovery.
ADSM uses it to find tape information that it needs if it cannot access
the data base because of a data base failure.

If you run the log in roll-forward mode and your data base crashes, you
can restart adsm and it will use the VOLHISTORY file to find and mount
the most recent data base backup tape and restore your data base from
the point of failure.

I don't think the Volume History file is required for any other reasons.

I can't think of any reason you need to keep ANY ENTRIES in the
VOLHISTORY file that are OLDER than the OLDEST data base backup you
would use in a recovery situation.

Okey Dokey, can somebody counter that argument?


===============================================================
Wanda Prather
Johns Hopkins Applied Physics Lab
wanda_prather AT jhuapl DOT edu

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









        ----------
        From:   Nancy Stevens[SMTP:Nancy_C_Stevens AT csc DOT com]
        Sent:   Friday, February 06, 1998 1:36 PM
        To:     ADSM-L AT vm.marist DOT edu
        Subject:        Re: Parameters for delete volhist

        Thanks, for your reply.  Like you, I think it would be okay to
delete many
        of these volumes.  But, my real question is:  What do these
different
        "type" parameters mean (stgnew, stgdelete, stgreuse, dbbackup)?
These are
        parameters you can add to the DELETE VOLHIST command.  The Admin
Ref says
        that by adding "type=stgnew" to the command it "specifies to
delete only
        recoreds that both contain information about new sequential
access storage
        volumes and meet the date and time criteria you specify".  What
volumes are
        these?  Like I said, when I do a "query volhist", I see volumes
of
        type=stgnew going back to 1995.  These obviously aren't "new"
anymore.  If
        someone could explain this to me, I would really appreciate it.

        Thanks,
        Nancy