RE: Reducing downtime for backups

[Chris Bipes <chris.bipes@xxxxxxxxxxxxxxx>]

But as you increase disk arms, i.e. drives, you get higher through put.  As
your through put goes up, your IOP, CPU and Main ASP Disk load will go up.
Now if those do NOT become a bottle neck, you will still see 90+% disk
utilization on your secondary ASP BUT your run time will go down.

Any body want to back me up on this?

And I do not take any offense to you or anyone on this list questioning what
I post.

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: prumschlag@phdinc.com [mailto:prumschlag@phdinc.com]
Sent: Friday, November 30, 2001 1:22 PM
To: midrange-l@midrange.com
Subject: RE: Reducing downtime for backups




Chris,

Don't take this wrong, but I have trouble swallowing that.  I have to go
back to
basics on this and in my (admittedly simplistic) view it goes like this:
CPU -
Fast;   Disk - Not So Fast,   Tape - Really Slow.  For this job, the CPU has
nothing else to do, so it will always be waiting on the disks, so no matter
how
many I throw at it the disk busy percentage will always be high.  If my
lousy
memory serves me correctly, IBM invented *SAVF files for the express purpose
of
reducing downtime for backups.  Has tape processing improved so much that
one
tape drive can record data faster than 6 read/write heads on disk?  Or is it
possible that the RAID processing on these disks is causing so much
thrashing
that the whole system is bouncing up and down in the computer room?

Phil