Re: Troubleshooting performance issues

2002-11-06 05:22:37
Subject: Re: Troubleshooting performance issues
From: Zlatko Krastev/ACIT <acit AT ATTGLOBAL DOT NET>
Date: Wed, 6 Nov 2002 12:20:36 +0200
---> TCPWindowsize 64512

TSM Reference Manual:
Specifies, in kilobytes, the amount of receive data that can be buffered
at one time on a TCP/IP connection.
3. A window size larger than the buffer space on the network adapter might
degrade throughput due to resending packets that were lost on the adapter.
Try "tcpwindowsize 256" instead

---> 3 IDE drives

Is the DB on separate drive? How many volumes ?!?! What is the drive and
what is the DB cache hit ratio?
IDE drives perform terrible if you issue more than one operation against
them - commands are queued in the device driver or controller but the
drive is executing them one-by-one. If you have master+slave drive on same
IDE channel - one drive have to wait until the other finishes its
operation and frees the IDE bus.
Do yourself a favour - buy one or two SCSI drives. It is a server on the

---> 3 drives.  OS - DB - LOG

Your network is 100 Mb/s (~= 10 MB/s). The drives in 3583 are LTO, right
(15MB/s). You wrote 3 drives (and small diskpool or no at all) - so you
are attempting to backup direct to tape? Thus your network is unable to
feed the beast quickly enough and LTO has to stop-rewind back-start.
Usually under such circumstances you not only are wearing out to drive but
also are getting 1-3 MB/s (or less) tape-write rate.

---> Network data transfer rate:          570.67 KB/sec

It might be worth to check the network (preferably after paying attention
to above remarks). The TSM server is 100+Full+NoAuto but what about the
client nodes, switch(es)?

Zlatko Krastev
IT Consultant

Etienne Brodeur <ebrodeur AT SERTI DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
05.11.2002 16:44
Please respond to "ADSM: Dist Stor Manager"

        Subject:        Troubleshooting performance issues

I have some major performance issues during archive operations.  I also
have bad performance durning backups, but the backup window is large so
they complete without any problems.  I can't seem to put my finger on the
bottleneck and was wondering if someone had a document to recommend when
looking for performance issues?

Here is the scenario:

TSM server on W2K (SP2)
3 IDE drives.  OS - DB - LOG
100 Mbs/Full Duplex (not auto)
LTO 3583 SCSI attached to the server
Server Options:
CommTimeOut 60
IdleTimeOut 30
BufPoolSize 81920
LogPoolSize 512
TxnGroupMax 256
MoveBatchSize 256
MoveSizeThresh 500
UseLargeBuffers Yes
AuditStorage Yes
TCPWindowsize 64512
TCPNoDelay Yes

There are 10 clients running 4.2.2.x (mostly  I have not set any
performance settings in the DSM.OPTs.  The servers have less than 10 GB of
data each.  I have 5 of them archiving to tape at the same time and they
are all running very slowly:

05-11-2002 01:29:29   ANE4952I (Session: 5848, Node: HY-ORAPED-2000) Total

                       number of objects inspected:  102,322
05-11-2002 01:29:29   ANE4953I (Session: 5848, Node: HY-ORAPED-2000) Total

                       number of objects archived:    86,989
05-11-2002 01:29:29   ANE4961I (Session: 5848, Node: HY-ORAPED-2000) Total

                       number of bytes transferred:     6.46 Go
05-11-2002 01:29:29   ANE4963I (Session: 5848, Node: HY-ORAPED-2000)  Data

                       transfer time:                11,875.56 sec
05-11-2002 01:29:29   ANE4966I (Session: 5848, Node: HY-ORAPED-2000)
                       data transfer rate:          570.67 KB/sec
05-11-2002 01:29:29   ANE4967I (Session: 5848, Node: HY-ORAPED-2000)
                       data transfer rate:        511.71 KB/sec
05-11-2002 01:29:29   ANE4968I (Session: 5848, Node: HY-ORAPED-2000)
                       compressed by:                    0%
05-11-2002 01:29:29   ANE4964I (Session: 5848, Node: HY-ORAPED-2000)
                       processing time:            03:40:43

This was the fast one, I also have this W2K client:

05-11-2002 07:25:34   ANE4952I (Session: 5906, Node: HY-OSRV-2000)  Total
                       of objects inspected:    8,424
05-11-2002 07:25:34   ANE4953I (Session: 5906, Node: HY-OSRV-2000)  Total
                       of objects archived:     8,364
05-11-2002 07:25:34   ANE4961I (Session: 5906, Node: HY-OSRV-2000)  Total
                       of bytes transferred:     2.76 Go
05-11-2002 07:25:34   ANE4963I (Session: 5906, Node: HY-OSRV-2000)  Data

                       transfer time:                2,871.55 sec
05-11-2002 07:25:34   ANE4966I (Session: 5906, Node: HY-OSRV-2000) Network
                       transfer rate:        1,008.95 KB/sec
05-11-2002 07:25:34   ANE4967I (Session: 5906, Node: HY-OSRV-2000)
                       data transfer rate:         97.15 KB/sec
05-11-2002 07:25:34   ANE4968I (Session: 5906, Node: HY-OSRV-2000) Objects

                       compressed by:                    0%
05-11-2002 07:25:34   ANE4964I (Session: 5906, Node: HY-OSRV-2000) Elapsed

                       processing time:            08:17:01

Please help me!  I don't know where to look anymore.


Etienne Brodeur

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