Based on your last paragraph, I would agree, but in a conservative practice,
I might give it a couple of extra days, just to be sure.

Your second paragraph is not exactly correct....  In a nutshell, here is how
it works....

ADSM will use the volhistory file to keep an audit trail of his tape usage -
not only STGNEW and STGDELETE, but also Import, EXPORT and Backup as well.
** All of this information is also recorded in the Data Base as well. **  The
volume history files are only used in recovery situations as you determined,
but primarily to bring the DB back into synch about what may have been lost.
The thing I am always wary about is a restore of the DB, only to find out
that the last backup was corrupt, or the tape can't be read..... PARANOIA!
That's why I keep 22 days worth of files.

Jerry Lawson
jlawson AT thehartford DOT com


______________________________ Forward Header __________________________________
Subject: Re: Cleaning Up Old VOLHIST Entries
Author:  INTERNET.OWNERAD at SNADGATE
Date:    7/28/97 3:36 AM


This implies that all entries older than "nn" days will be deleted.  I am
just a little unclear on what the purpose of this file is but I think I now
understand.  Please correct me if the following proves me totally
ignorant....

During normal operation ADSM decides certain tapes are no longer required
and records them as STGDELETE in volume history.  It also decides it needs
another tape from the scratch pool and records this as STGNEW in volume
history.  This information (and here is the critical bit!) is not
specifically stored in the database but the current, up to the minute,
status of each tape currently in use is.  Once  a usable database backup
exists, the information in the volume history file from prior to the time
of the backup is redundant because ADSM doesn't look in volhistory to know
the status of a tape except when restoring a database.  This implies that
volhistory is used for forward recovery as well as full database restore.

In my case, I use a daily database backup followed immediately by a backup
of volhistory (and devconfig) to removable disk.  With the database backup
tape and removable disk available, I am now assuming that I can delete all
volhistory entries right up to the time the database backup began.

Murray Nicholas
Systems Specialist
HALTEK PTY LTD