Greg,

     FWIW... I use VSTORE to validate our full backup each weekend. I have
     3 DAT drives and use the parallel option in TurboStore to write to all
     drives at the same time. Since I'm in an operatorLESS environment, I
     do the VSTORE on the same drives that the tapes were created on. It
     may not be 100%, but it's sure better than nothing!!!


     Bob Mueller                [log in to unmask]
     Datascope Corp.            201-967-3680


______________________________ Reply Separator _________________________________
Subject: Request for comment on backup procedures
Author:  "Stigers  Greg ~ AND" <[log in to unmask]> at INTERNET
Date:    6/17/98 2:10 PM


Sorry for the waste of bandwidth, but I am in a win-lose situation,
where the loser is liking to have their competancy questioned. Also, I
imagine that in this context, our proposals raise questions of liability
if these changes are made for us, but not for others. I am interested in
just criticisms of the following, both any inadequacies in what I
propose, and in the current procedures as described.

I have requested that our data center verify our weekly full backups,
which are performed on Sundays. They are questioning this, and
suggesting that if we question DAT integrity, we move to a technology
that we do trust. I am also told that no one else regularly verifies
backups along these lines.

The details of the request are to split the backup across our three
available DAT / DDS drives, along the lines of how we have split the
daily backups, in the interest of backup up and adding verification in a
smaller window of down time. I have specifically requested that we not
'strip' the backup in parallel across the three tapes, because in that
scenario, if one tape ever has problems, then the entire backup (with
the possible exception of files so small as to fit on one strip on one
tape) is unusable. This contrasts with three seperate backups that
backup all files; then, if one tape goes bad, only that tape is lost.

I have asked that the VSTORE version of the STORE software be used
against the weekly full backups to confirm that what is on the tape is
what is on disc.

Also, I have asked that due to well-known issues with DAT calibration,
the tapes be rotated among the three drives before the VSTORE, so that
we are reasonably sure that a tape made on one drive is readable on
another. This does leave us suceptible to drift over time, where an
older tape can no longer be read due to drives drifting out of
calibration. Perhaps the rotation should alternate direction (A->B,
B->C, C->A one time, then A<-B, B<-C, C<-A the next), to reduce the
likelihood of this.

While moving to DLT is probably well advised, doing so would almost
certainly take longer than our data center requesting that their tape
library provide three tapes for full backup and implementing a
procedural change. In any case, we would merely want variations of these
procedures using a more robust technology.