On Fri, 2002-11-22 at 08:32, Brian L. Nick wrote:
> We are running TDP for Domino 1.1 on a Domino server 5.08 running on NT.
> TSM server 4.2.1.9 is running on OS/390 2.10. The initial restore process
> is working well, but we are attempting to apply 2 days worth of transaction
> logs and we are moving over 6 Gb of data and then the process appears to
> hang and the restore process does not complete. We archive out Domino
> transaction logs to TDP hourly.
>
>  My Domino group isn't happy with the processing time to recover a single
> mail file.

...and herein lies a future preventative. Is it *really* necessary to
backup log files every hour?

Suppose you do hourly log backups after a weekly full backup on Sunday
at 0100. You have data loss at 1500 on Friday, and start a restore. You
will have to restore the last full backup, and then you have to restore
*134* separate log backups. If you're using, say, DLT tape, and not
collocating, you may get to run 135 separate mounts, spin-forwards,
restores, log replays, rewinds, and dismounts for each file you're
restoring. Each transaction requires a minimum of 2 minutes (if there's
little or no spin-forward/rewind) plus, say, 1 minute of log playback. 3
minutes/transaction times 135 transactions equals 405 minutes, or more
than 6 hours per file. Minimum. If you have to run to the end of a tape
for a log, add 6 to 8 minutes per transaction. Each file restore *could*
run as much as 870 minutes. The real world is, of course, somewhere
inbetween, but an average of 10 hours per file isn't pretty, no matter
how you slice it.

Such is the curse of (necessarily) single-threaded restores. Do yourself
a favor. Cut your log backups to 2 or 3 a day. Your Domino group won't
like it, but do the math for them. They'll like it better then.

--
--
Mark Stapleton (stapleton AT berbee DOT com)
Certified TSM consultant
Certified AIX system engineer
MCSE