I have no experience-based input to offer on the performance benefits of
multiple, smaller db volumes versus fewer, larger db volumes. But
regarding a couple of other points you raised:
- For a database restore, there is no requirement to map the database
volumes one for one. As long as the destination volumes have sufficient
space to contain the restored db, the number of volumes is
inconsequential.
- For volume consolidation, you don't need to do anything so drastic as
unloading and reformatting the db. Rather, just define the new db
volume(s), then use the DELETE DBVOLUME command, which will move the data
from the old volume to other db volumes. You can do this while the TSM
server is running.
Regards,
Andy
Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Development
Internal Notes e-mail: Andrew Raibeck/Tucson/IBM@IBMUS
Internet e-mail: storman AT us.ibm DOT com
The only dumb question is the one that goes unasked.
The command line is your friend.
"Good enough" is the enemy of excellence.
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 12/10/2004
07:43:26:
> Hello List -
>
> TSM 5.2.3
> z/OS 1.5
>
> When I came on board as the TSM Admin eight months ago, my site had
> 46 db volumes of 500MB each. Since that time, I've had to increase
> the DB a few times, so (not knowing otherwise), I've added 4 more
> volumes of 500MB each. I have no complaints about system
> performance, as we are backing up 200 nodes and get through most
> days without problems. But, we are a growing system and I want to
> make sure we are properly positioned for the future.
>
> If I consolidate the database over fewer volumes (say, 10 2500MB
> volumes, rather than 50 500MB volumes), will there be any
> performance gains? So far, the only reason I can see to do it, is
> to have fewer volumes to declare during a database restore at the DR
> site, and I'd like to have more of a reason to undertake the task.
>
> Also, if I do move forward with the volume consolidation, should I
> do a UNLOADDB, LOADFORMAT, LOADDB first? Will that lead to smoother
> database maintenance?
>
> Thanks in advance.
>
> David Moore
> State of LA / DOA / OCS
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