ADSM-L

Re: Slow backup from Netware of small files

2004-04-28 01:51:23
Subject: Re: Slow backup from Netware of small files
From: Christo Heuer <christoh AT ABSA.CO DOT ZA>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 28 Apr 2004 07:48:25 +0200
Hi Eric,

You will not get better performance than that - although, like Richard says,
it is common on all platforms it is worse on Netware.
You should definately switch off compression if you had it on - the reason
you are getting worse performance(this is my opinion anyhow), is because
Netware uses the
1st CPU in a multiple CPU box all tasks will queue for this processor - even
like in our case where we have 4 processor Netware boxes.
The Netware TSA's are all single threaded to the 1st CPU - inlcuding the
TSA's TSM uses to talk to the file system to read the data.

I've played with all the different tuning parameters you can use in TSM and
some woked better and others much worse - the best was not to use
compression at all.
We eventually settled on using flashcopy to another LUN on the SAN -
mounting that volume on another box - that was not running any workload -
and then running the backups from there.

Let me know if you need more info on the actuall parameters we played with
and what effect it had on the throughput.

Cheers
Christo

----- Original Message -----
From: "Eric Winters" <ewinters AT AU1.IBM DOT COM>
To: <ADSM-L AT VM.MARIST DOT EDU>
Sent: Tuesday, April 27, 2004 10:46 AM
Subject: Slow backup from Netware of small files


> Dear All,
>
> ENVIRONMENT
> ==============
> TSM Server 5.2 on AIX 5.1
> TXNGROUPMAX                     256
> TCPWINDOWSIZE                  64
>
>
> TSM Backup/Archive Client 5.2 on Netware 5
> TSANDS.NLM ver 10110.95
> TSA500.NLM ver 5.05d
> SMDR.NLM ver 6.50c
> TCPWINDOWSIZE                      64
> TCPBUFSIZE                                 32
> LARGECOMMBUFFERS           NO
> TXNBYTELIMIT                            25600
> PROCESSORUTILIZATION    10
> RESOURCEUTILIZATION         5
>
> Gigabit Network
>
> PROBLEM
> =========
> Whilst backup performance of large files is very good (approx 16 MB/s) the
> backup performance of small files (50 KB to 300KB) is extremely poor (300
> KB/s).
> Backups are straight to a diskpool.
> I'd be interested in hearing from anyone with any experience of successful
> backup of small files in a Netware environment, or anyone who has any
ideas
> as to what might be done to improve the situation.
>
> Thanks as always,
>
>
> Eric Winters
> Sydney
> Australia

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