Hi Rick,
ADSM/TSM *does* have roll-forward capability, provided that
the recovery log is intact at the time of the failure. The
information necessary for roll-forward recovery is contained
in the recovery log when the ADSM server log mode is set to
ROLLFORWARD (default is NORMAL, which does not afford the
roll-forward capability).
If the recovery log is in roll-forward mode, and it is
intact at the time of the failure, then you should be able
to restore the database up to the time of the failure. The
restore operation will start with the last full backup of
the database, followed by any subsequent incremental
database backups, and finally apply the changes from the
recovery log.
As a general rule of thumb, if you are in a position where
you need to restore the database, the DSMSERV RESTORE DB
operation is the preferred method. In order to be able to
perform this operation, you should be using the BACKUP DB
command on a regular basis to take full and incremental
database backups. This by itself allows you to restore the
database up to the time of the last BACKUP DB operation.
With the recovery log mode set to ROLLFORWARD, you can
restore the database up to the time of failure (again,
provided that the recovery log is intact).
DUMPDB/LOADDB should be used only as a last resort. In
this case, I would recommend contacting IBM support
*before* attempting this operation just to be sure that
you have no other options.
Historical note: Back in ADSM V1, DUMPDB/LOADDB was the
only means of backing up and restoring the database. In
addition, an AUDITDB was often required. These processes
were/are painfully slow, and should only be used when
absolutely necessary, which is why I recommend contacting
IBM support first. ADSM V2 introduced the BACKUP DB and
RESTORE DB commands, which run much faster and provide
more comprehensive protection.
Please refer to the ADSM (or TSM) Administrator's Guide for
further information on this topic. The Admin Guide contains
information on protecting the server, including discussions
on the roll-forward capability, backing up the database,
mirroring the database and recovery log, etc.
Best regards,
Andy
Andy Raibeck
IBM Storage Systems Division
ADSM Client Development
e-mail: storman AT us.ibm DOT com
"The only dumb question is the one that goes unasked."
As we've been evaluating ADSM I guess I've been making a serious
error in understanding backup/recovery.
From reading the post below from another thread, do I now understand
correctly that ADSM has NO ROLL-FORWARD recovery procedure? In other
words, if you put down a full backup and incrementals, there is no
way to roll forward to the point in time when the db was lost?
Maybe my terminology is wrong - posting incrementals to a full may be
"rolling-forward". But, the point is that the recovery log at the
time of a crash is unusable when you must must do a restore from
full/incremental backups.
Is this correct?
Thanks
Rick
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