ADSM-L

Re: Database backup performance

2001-06-27 12:37:41
Subject: Re: Database backup performance
From: John Naylor <John.Naylor AT SCOTTISH-SOUTHERN.CO DOT UK>
Date: Wed, 27 Jun 2001 17:36:47 +0100
Zoltan,

We are OS390 too.
Last full backup of 3.7.20.0 database took
1 hour 45 minutes   (4464417 pages)  to STK 9840 cartridge
So you definitely should be faster

John





"Zoltan Forray/AC/VCU" <zforray AT VCU DOT EDU> on 06/27/2001 05:04:04 PM

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

To:   ADSM-L AT VM.MARIST DOT EDU
cc:    (bcc: John Naylor/HAV/SSEG)
Subject:  Re: Database backup performance



I guess I should have clarified that the server is on OS/390, not *NIX !!

Thanks for all the responses on how long it takes. Now, how about ways to
improve the speed ?

I am trying a backup to 3590 drives, to see how much of a difference it
makes. So far, there does seem to be a speed difference.

I also went through the ADSM job log and collected some statistics.

The last FULL DB backup took more than 5-hours for 3665050 pages !!!

*******************************************************************************
>>> Hello, we full backup our 22.3 GB DB (assigned, used 92%)
in 39 minutes, using Magstar 3590E cartridges in the 3494 robotic.
Th DB is laying on mirrowed ssa-disks (7133) using 18GB-disks
(ibm7133-8518)
Processor in RS600/H50, OS/AIX 4.3.3 , TSM4.1.3.0

...mabe you should first check the capability of the disks where your db
is located - what you would get there by reading on unix for example
a simple test would be done using dd for example
( if you have your server on unix)
Example:
# time dd if=/some_data_located_on_the_db_disk of=/dev/null bs=1024k
count=100
100+0 records in.
100+0 records out.

real    0m8.396s
user    0m0.010s
sys     0m1.890s
#
... would get the time to just read 100MB ( just at the time of the test )
running the example -dd- test again can to unrealistic low times when
data is cached, so a new test should be done with new data ( if=...)








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