RE: Reducing downtime for backups

[prumschlag@xxxxxxxxxx]

Chris,

I can't dedicate one of the IOP's we have to the *SAVF ASP, but if I read the
statistics correctly, the IOP is not the bottleneck.  PM400 is showing that the
disks (six 10k RPM drives) in this ASP are running 90-95 percent busy while the
backup is running.  The drives in the System ASP are running about 10 percent
busy.  The CPU is running about 35% (dual processor).  I could throw money at
the problem (more disks in the *SAVF ASP) but I'm not convinced that would help
much.

Phil

     Message: 6
     From: Chris Bipes <chris.bipes@cross-check.com>
     To: "'midrange-l@midrange.com'" <midrange-l@midrange.com>
     Subject: RE: Reducing downtime for backups
     Date: Fri, 30 Nov 2001 10:55:46 -0800
     Reply-To: midrange-l@midrange.com

     Once upon a time I had old drives and new drives.  They were on separate
     IOP's/controllers.  I set the old drive into a user ASP.  Saving to save
     file in that ASP was FAST.  No I/O contention or IOP overload.  If the ASPs
     are on the same IOP you may get IOP overload.  If the save files are in the
     same ASP, you will get disk/arm contention.  Tapes will out perform that.
     Put your secondary ASP onto a different Buss and you will get excellent
     performance.

     You may only need a faster IOP for your tape drive to improve performance,
     or move your tape controller to a different IOP than your disk
     controller(s).


     Christopher K. Bipes       mailto:ChrisB@Cross-Check.com
     Operations & Network Mgr  mailto:Chris_Bipes@Yahoo.com
     CrossCheck, Inc.           http://www.cross-check.com
     6119 State Farm Drive      Phone: 707 586-0551 x 1102
     Rohnert Park CA  94928     Fax: 707 586-1884