Paul, I read what you wrote up and that is great, but have you ever
tried defining the stgpools on your disk subsystem as RAID 0 to compare
the difference between RAID 0 and RAID 5. It is just curiosity, since
all of mine have always performed better with RAID 0.

It is not clear to me what model of disk subsystem you were using from
the note.

Thanks

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Paul Ripke
Sent: Tuesday, April 15, 2003 7:28 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: FAStT700 RAID 0,1,3,5? for DB and Stgpools.

Check the archives for the recent thread with subject "Limitation of
TSM DB Volumes" - stripes and mirrors are fine for the DB, so long
as you keep the number of DB volumes high enough.

Also, check out <http://msgs2.adsm.org/cgi-bin/get/adsm0303/285/1.html>
for my experience running RAID5 disk storage pool volumes, using
software
RAID5. It is possible, just have to be careful with stripe sizes.
Likewise,
you need to keep the number of volumes high enough to keep the disks
busy.

On Wednesday, Apr 16, 2003, at 05:02 Australia/Sydney, Adolph Kahan
wrote:

> I would not recommend RAID 5 for the stgpools. While backing up data
> TSM
> will only be doing writes to the stgpools and with RAID 5 you pay a
> performance penalty for each write.  I would just make this RAID 0.
> I've
> done some tests with various RAID adapters and in each case I found
> that
> RAID 0 for the stgpools, provided better backup throughput than the
> RAID
> 5 implementation.
>
> Adolph Kahnan
> AK Consulting Inc.
>
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf
> Of
> Talafous, John G.
> Sent: Tuesday, April 15, 2003 2:22 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: FAStT700 RAID 0,1,3,5? for DB and Stgpools.
>
> We're looking seriously at a FAStT700 attached to an AIX machine for
> our
> DB
> and Stgpools.  At present, I am considering 36GB 15K RPM drives for DB
> and
> Log. I am considering 73GB RPM 15K drives for stgpools. (I am open
> further
> to suggestions on this!) My question is in regards to the RAID
> configuration.  Since TSM likes to mirror DB and logs, would RAID-0 be
> best
> there? How about stgpools?  RAID-5?  Any experience in this area?
>
> Any input would be appreciated and TIA,
> John G. Talafous              IS Technical Principal
> The Timken Company            Global Software Support
> P.O. Box 6927                 Data Management
> 1835 Dueber Ave. S.W.         Phone: (330)-471-3390
> Canton, Ohio USA  44706-0927  Fax  : (330)-471-4034
> talafous AT timken DOT com           http://www.timken.com
>
>
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> The Timken Company
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>
--
Paul Ripke
Unix/OpenVMS/TSM/DBA
101 reasons why you can't find your Sysadmin:
68: It's 9AM. He/She is not working that late.
-- Koos van den Hout