==> On Wed, 30 Nov 2005 11:52:24 -0500, Thomas Denier <Thomas.Denier AT 
JEFFERSONHOSPITAL DOT ORG> said:


> I am working on plans for disaster recovery at a hot site that will not
> necessarily have the same number and size disks as our primary site. I know
> that a TSM database restore does not require matching volume sizes, as long
> as the aggregate size of the replacement volumes is sufficient. However, I
> am not sure of the criterium for sufficiently. Experience at previous
> disaster recovery tests indicates that it is not sufficient to have room for
> the used pages. Is it neccessary to equal or exceed the available space in
> the original configuration, or only to equal or exceed the allocated space
> in the original configuration?


I think that assigned_capacity might be your minimum; I assigned_capacity -
maximum reduction might do it, but would suggest using just plain
assigned_capacity.

My "generate a shell script which will restore this TSM server" script does
the following math:


    my @lines = &tsm_query($s,'select capacity_mb from db');
    $dbsize = shift (@lines);

[...]

    ndb=`expr \\` expr \$dbsize / \$ppsize \\` + 1`


ppsize is the Physical Partition size of the volume group in question.  I add
one to it to keep me from having to worry about rounding. :)


This calculation works, so you can use it as a ceiling for your own
experiments.  Here's an example of the output of that script.  If you're
dealing with storage primitives other than AIX volume groups, then the details
will be different, but the principles should remain the same.


- Allen S. Rout


"restore-me.sh" for my "TEST" tsm server.

#!/bin/sh

. /var/tsm/test/dsmserv.env

vg=tsmvg
dbsize=1024
lgsize=256
ppsize=64


ndb=`expr \` expr $dbsize / $ppsize \` + 1`
nlg=`expr \` expr $lgsize / $ppsize \` + 1`

echo Making DB volume in $vg: $dbsize MB, $ndb PPs
mklv -y ttestdblv_01a $vg ${ndb}

echo Making DB volume in $vg: $lgsize MB, $nlg PPs
mklv -y ttestlglv_01a $vg ${nlg}

echo dsmserv format 1 /dev/rttestlglv_01a 1 /dev/rttestdblv_01a
dsmserv format 1 /dev/rttestlglv_01a 1 /dev/rttestdblv_01a

echo dsmserv restore db TOD=TODAY TOT=NOW
dsmserv restore db TOD=TODAY TOT=NOW