Re: Disaster Recovery - how good are your plans?

["Henrik Krebs" <hkrebs@xxxxxxxxx>]

I've never done a _disaster_ recovery  (knock knock), but that very
fact once led the auditor to demand a full scale test. It was way back
on an model B35, so the exact timing has no interest any longer.
Beeing unable to get a spare AS/400 to do the test on, I was forced to
initialize all disks and do it on the production machine. Not that I
was very motivated! I trusted the backup and found no reason to waste
time testing (X-ref of save times vs modifications and testing a
restore of different objects was done all the time). But I _did_ learn
something from the test and changed my backup: We did not save access
paths (neither before nor after the test), so even with a slow tape
there were waiting time. What I learned was, that a careful planning
of the save sequence and a well prepared plan for the restore sequence
was essential in order to be 'up and running' with the key systems
much earlier.

At the test I could release the key systems for users after about 80%
of the restore time has passed.

After adding a field 'sequence' to the backup table and redoing the
recovery instruction my estimate was that the users could start using
a slow but running system after maybe 60% of the time. This difference
might mean one whole production day! Review the object sizes and the
files's RECOVER() parameter,

So option 21 on 'GO SAVE' is far from optimal. Review the object sizes
and the files's RECOVER() parameter, differentiate the save commands
taking the restore in consideration, split objects in libraries
depending of where and when used etc.

Henrik
http://hkrebs.dk


--------------------------------

From: oliver.wenzel@cibavision.novartis.com
To: MIDRANGE-L@midrange.com
Subject: Disaster Recovery - how good are your plans?
Date: Sun, 12 Aug 2001 13:03:59 +0200
Reply-To: midrange-l@midrange.com

Hello,

as I'm sitting here waiting for the PTFs to install I'm wondering how
good
everybody's disaster recovery plans are?

We had to do a complete system reload on monday due to the crash of a
mirrored disk pair. The call to IBM went
out on monday morning 7am and were finished with the reload on
wednesday
morning 2am.

Have you ever had to do a complete reload? How did it go? What kind of
backup do you do? Journalling?

We were very lucky that the crash happened on a sunday evening. Friday
night
backup had gone well and no jobs
were running on the weekend (except some reorgs). So we had a clean
database...

Good luck

Oliver