ADSM-L

ADSM Technical Support Bulletin

1995-06-28 21:00:37
Subject: ADSM Technical Support Bulletin
From: "Jacquelyn B. Reith" <jreith AT VNET.IBM DOT COM>
Date: Wed, 28 Jun 1995 18:00:37 PDT
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=====          AdStar Distributed Storage Manager          =====
=====                Technical Support Team                =====
=====                                                      =====
=====          *******  B U L L E T I N  *******           =====
=====                                                      =====
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ABSTRACT

Problem in the ADSM FORCE BACKUP command

DETAIL

IMPORTANT NOTICE FOR ALL ADSM CUSTOMERS USING COMPRESSION UTILITIES

On March 7, 1995, IBM posted a bulletin discussing a problem in the
ADSM compression buffering algorithm.  Since that time, the algorithm
has been fixed, and PTFs have been made available for all client
platforms.  In addition, IBM provided ADSM server utilities to help
detect and manage files that may have been affected by this problem.
These utilities have been made available in PTFs for the various
server platforms.

A problem has been discovered in one of these utilities: the
FORCE BACKUP command.  This problem only affects forcing backup of
files that were backed up from UNIX client platform.  The FORCE BACKUP
command is used to mark a set of files to be backed up again during
the client's next incremental backup of the file space containing the
file.  However, for client files residing on UNIX platforms, this
backup was NOT taking place after the FORCE BACKUP command was issued
for these files.  A fix for this problem is being provided with the
applicable APAR for your server platform:

MVS:       PN72367
VM:        PN72909
AIX:       IC10622
OS/2:      IC10621

When using the compression utilities, a candidate list of files is
created using the AUDIT COMPRESSION command.  This list is displayed
using the QUERY COMPRESSION command.  The output of this command shows
which files are "active" backup or archive files, and the detailed
format of this output also indicates whether or not the file has been
"forced."  The FORCE BACKUP command can be used to mark for backup
any "Active Backup" file included in this candidate list.  In doing
so, files that may have been affected by the compression
buffering algorithm problem and still reside on the client's
workstation are backed up again during the client's next incremental
backup, using the corrected client compression code, or backed up
without compression if the new client code is not yet installed.
Again, for files residing on UNIX platforms, this backup was not
taking place.

IT IS IMPORTANT that an entry identified as "active" is not removed
from the compression candidate list until it has been verified that
either:  (1) the candidate file was not affected by the compression
problem or (2) the file has been successfully re-backed up or
re-archived.  You can tell if a candidate file that was "forced" has
been backed up again if its status displayed in the output of the
QUERY COMPRESS command now shows the entry as an "Inactive Backup"
entry.  Entries that are "Marked for Forced Backup" and are still
of type "Active Backup" have not yet been backed up again.

If you think you may have removed an "active" UNIX platform entry
(using the REMOVE COMPRESSION command or CLEANUP COMPRESSION command),
before it was verified to have been re-backed up and you no longer
have a record of these suspect files, you will need to again perform
the AUDIT COMPRESSION procedure.  This is needed to re-identify these
files, so they can be marked to be backed up, using the corrected
FORCE BACKUP command.  Please refer to the closing text of one of the
APARs listed above, for more details regarding procedures to use after
receiving the corrected code.
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