RE: Reducing downtime for backups

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

-----Original Message-----
From: jt [mailto:jt@ee.net]
Sent: Friday, November 30, 2001 7:25 AM
To: midrange-l@midrange.com
Subject: RE: Reducing downtime for backups


Phil,

My experience is that saving to *SAVF is SLOWER than going directly to
tape...  I don't understand this, at all, but that has consistently been my
experience.  (However, that was 5 years ago.. ***things change***.. plus I
didn't try going to a *SAVF in a different ASP...)  I assumed there was a
bottleneck in the I/O controllers involved...

Easiest solution...: throw money at the problem (fastest tape drive you can
afford)...