RE: Tape speed comparisons

["Ingvaldson, Scott" <SIngvaldson@xxxxxxxxxxxx>]

Changing the topic slightly, sorry Rob :)

The Search400 Administrator Tip of the day today is called "Want to speed up
your nightly backups? Use save files"
http://search400.techtarget.com/tip/0,289483,sid3_gci957211,00.html?track=NL
-176&ad=479313

Has anyone done any comparison testing on this?  It is my understanding that
after disk arm contention is taken into consideration that a save to SAVF
can actually be slower than a save to tape in many cases. 

My test results using a 42GB Library on an 810 were:

Save to SAVF (in system ASP) = 32 minutes
Save to 7208-342 = 93 minutes
Save to 3590-B1A = 26 minutes
Save to SAVF in separate ASP = 17 minutes
Save to one of Rob's fiber attached 3582's = estimated 12 minutes

We now have all of our backups using Save-While-Active.  The SWA time to
sync this 42GB library (706 objects) was about 20 seconds.

A friend used to run a Domino backup on a 170 with only one disk controller
to a SAVF.  They found that this backup ran twice as fast directly to a
3590.

Regards,

Scott Ingvaldson
AS/400 System Administrator
GuideOne Insurance Group

-----Original Message-----
date: Wed, 31 Mar 2004 08:56:55 -0500
from: rob@xxxxxxxxx
subject: Tape speed comparisons

Last night we changed several tape drives.

Our Domino backup used to run on a 3590E attached via 2749 to our 840. Now
it runs on a 3582 fiber attached to a 5704.
The time went from 4 tapes running  between 18:45-23:02 to 1 tape running
between 21:00 to 22:54.

Our DB2 backup used to run on a 3590E attached via 2749 to our 840.  Now it
runs on a 3582 fiber attached to a 5704.
The time went from 1 tape running from 00:16-05:00 to 1 tape running from
00:01-03:51.

Our TSM backup (which saves huge individual objects using SAVOBJ in one
library) used to run on TWO 3581's attached via 2749, reading the object
names individually off of a data queue from two separate backup jobs (one
for each tape drive) from our 840.  Now it runs on ONE 3582 fiber attached
via 5704. The time went from 10-12 tapes running from 22:00-08:14 to 5 tapes
running from 22:00-06:58.

Our 270 used to used to use a 25GB cartridge to save itself.  Now it runs on
a 3580 attached via 2749 card.  That save used to run on 1 tape from
00:01-01:46.  Now it runs from 00:01-00:46.

In summary,  the 3582 fiber attached via 5704 blows the doors off of the
3590E attached via 2749. And the 3582 fiber attached via 5704 blows the
doors off of the 3581 attached via 2749. And the older 3581 attached via
2749 card blows the doors off of the 25GB cartridge. Soon as we finish
duping tapes from our 3590E to the 3582, and get that new hardware for our
820, the 3590's are out the door.

Rob Berendt
-- 
Group Dekko Services, LLC
Dept 01.073
PO Box 2000
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com



   
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