For those who have not yet recovered any of your Informix databases via
ON-Bar/ADSM please note:


Problems that can occur with OnBar:
1.  Restoring  one dbspace.

If you issue the command "onbar -r <dbspace name>" to restore
a single dbspace, onbar will restore that dbspace then backup the logs
that had not been backed up, then start replaying all logs.  In this
case,
you cannot specify via onbar to not replay the logs that contain the
unwanted transactions. For example, if you dropped a table
that was in its own dbspace and you restored only that dbspace, onbar
will restore the dbspace and replay the logs.  The end result is
exactly what you started with before you started the restore.

The only other thing you could do would be a FULL system restore up to a
point in time.

2.  Restoring to a point in time.

If you issue the command "onbar -r -t 1998-01-30 06:00:00".  OnBar
should
restore up to this date and time or as close as it can and
stop the restore.   Informix OnBar has issues (Informix would not say
directly that it was a known bug) in trying to restore to a point in
time.  Sorry I have no more information on this.

3.  Restoring up to a given log number.

If you issue the command "onbar -r -n 4796".  OnBar should
restore all logs up to and including that log number, stop the
restore, and roll back all uncommitted transactions.  Onbar will
accomplish this and stop after the specified log number but... you get
errors in the onbar activity log and the Informix online log.  The
following errors are the result:

Onbar activity log:
1998-01-30 14:53:32 7122  5750 Completed restore logical log 4796.
1998-01-30 14:59:14 7122  5750 ERROR: Unable to commit the restore:
buc_fe.c : Archive API processing failed at line 867.
1998-01-30 14:59:14 7122  5750 ERROR: Unable to commit the restore:
Archive API error: not yet open.

Informix Online Log:
14:52:07  Checkpoint Completed:  duration was 0 seconds.
14:59:13  Assert Failed: Physical log file overflow
14:59:13   Who: Session(44, informix@fingfgl1, 7122, -1240295152)
                Thread(112, ontape, b61094d8, 1)
14:59:13   Results: OnLine must abort
14:59:13   Action: Reinitialize shared memory
14:59:13   See Also: /tmp/af.703f21
14:59:14  rsbuff.c, line 2659, thread 112, proc id 7136, OnLine must
abort.
14:59:14  Message 16501 not found.


The problem then becomes trying to bring up Informix: it fails. Since
the last log recovered did not have a checkpoint, there is the
possibility of having
inconsistent data.

Informix Tech. Support suggests locating the last log that was recovered
and did occur in a Checkpoint and restore up to that log.  For example,
rerun the backup with the command "onbar -r -n 4793".  The restore will
work and will stop after applying log 4793,  but the error will still
occur.  Since log 4793 was restored before the last Checkpoint occurred
the instance will come up and run.  After this, Informix recommends
running "oncheck -cDIn <instance>" to check the consisity of the data.

In talking with the tech support they said that it sounded like bug
72562
which is fixed in Informix 7.23.UC5 and 7.24.UC1.  Tech Support also
said that if you decide to upgrade, then they recommend getting
either 7.23.UC9 or 7.24.UC4.

You might like to check your current Informix Levels.  Note that no
problems were related to the ADSM client or server.

David Hendrix
dmhendri AT fedex DOT com