I do not believe that TSM starts a separate thread for each DB volume created. That is how disk stg pool volumes work, but not the DB. The DB is read sequentially from what I understand.
-- Joshua S. Bassi Independent IT Consultant IBM Certified - AIX/HACMP, SAN, Shark Tivoli Certified Consultant- ADSM/TSM Cell (408)&(831) 332-4006 [EMAIL PROTECTED] -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED]] On Behalf Of Salak Juraj Sent: Monday, November 12, 2001 2:06 AM To: [EMAIL PROTECTED] Subject: Re: Best Database Performance Hi, this has been discussed very often, you may ant to have a look into forums history on http://msgs.adsm.org. Database performace is all about random access times, not about speed of streaming. Basically, TSM will start one I/O in each database volume, so having 4 database volumes spread over 4 physical disk may be a good solutions. If your disk controller has sigificant amount of cache and good optimising alghoritm, enabling much more I/O on one disk could be helpfull. If you have almost no cache on controller and on your disks, this may slow down your DB significantly. There are few parameters in OPT file which affect the performance (parallel write, read with verify), there you can gain some speed at the costs of security. Do allow as much software disk cache as possible, it usually helps a lot. Berst Regards Juraj Šalak Asamer Familienholding G M B H EDV Unterthalhamstraße 2 A-4694 Ohlsdorf Österreich www.asamer.at Büro: +43 7612 799 529 Mobil: +43 664 528 6474 e-mail: [EMAIL PROTECTED] -----Original Message----- From: Andy Carlson [mailto:[EMAIL PROTECTED]] Sent: Friday, November 09, 2001 4:16 PM To: [EMAIL PROTECTED] Subject: Best Database Performance Does anyone have a feeling about what is best for database performance? I have, since we moved to AIX, taken the 4 physical drives (actually 8 with ADSM mirroring), and striped it into one large volume. I saw a post the other day that suggested that maybe splitting it to 4 individual volumes might be better, as ADSM can schedule across these volumes. What I am seeing leads me to believe that ADSM is hitting one volume, and it's mirror predominately. Was I better off striped? Any suggestions? Thanks for any info. Andy Carlson |\ _,,,---,,_ [EMAIL PROTECTED] ZZZzz /,`.-'`' -. ;-;;,_ BJC Health System |,4- ) )-,_. ,\ ( `'-' St. Louis, Missouri '---''(_/--' `-'\_) Cat Pics: http://andyc.dyndns.org/animal.html
