Ruddy,

In a test that I did on a client site, average file size can account for
huge performance differentials when using LAN-Free. In one case, I ran a
test that compared transfer times of a 276480 byte file to a 2146435072 byte
file, the resultant transfer rate was .032 MB/sec. for the small file and
32.978 MB/sec. for the large file. The apparent reason for this difference
is that while file size differs greatly, each backup only required 1 DB
transaction. In this case, the DB transaction was the piece that was taking
the extra time and "degrading" the transfer rate of the small file.

Basically, it all boils down to how much data you can move within the TXN
limit. The more, the better the performance. If there are certain parts of
your file system where larger files are stored, you might want to try and
run a LAN-Free backup against them just to get a comparative baseline. If
you find performance improves, it might make sense to transfer the small
files over the LAN and the larger files over the SAN by establishing a new
management class that points to disk for small files and then modifying your
incl/excl file.

Hope this helps...

- Christopher Young

-----Original Message-----
From: Ruddy STOUDER [mailto:Ruddy.Stouder AT IRISLINK DOT COM]
Sent: Thursday, March 06, 2003 2:31 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Poor TSM Performances


Thanks ! But ... I have done all of them ... The reason why I am looking
here for info.

As I wrote, nothing is running on the 2 involved servers (so, no virus
protection software).
As I wrote, network cards are 10% used => no network settings involved.

                        Ruddy Stouder
                        Senior Technical Consultant
                        TSM Certified Consultant
                        I.R.I.S.
                        Rue du Bosquet 10 - Parc Scientifique de
Louvain-La-Neuve
                        B-1348 Mont-Saint-Guibert
                        ruddy.stouder AT irislink DOT com
                        <http://www.irislink.com>
                        Tel: +32 (0)10 48 75 09  -  Fax: +32 (0)10 48 75 40




-----Original Message-----
From: Richard Sims [mailto:rbs AT BU DOT EDU]
Sent: jeudi 6 mars 2003 15:25
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Poor TSM Performances


>I am quite disappointed by the TSM software performance. ...

Have you looked at the suggestions under "Backup performance" in
http://people.bu.edu/rbs/ADSM.QuickFacts ? Two classic causes of performance
problems are misconfigured networking and virus protection software.  File
system topology and network loading are also substantial factors.  How long
does it take a native W2000 file system scanning utility to traverse the
file system?  (File systems with thousands of files in one directory are A
Bad Idea.)  How long does it take a client running on the TSM server to
perform a backup without networking?  Have you pursued the items in the
Performance Tuning Guide? You have to break down the factors and examine
each. Blame TSM only if you ultimately find the sluggisness to be caused by
TSM.  But you have to do the basic systems analysis to isolate performance
factors in your mix.

   Richard Sims, BU