ADSM-L

Re: Server Tools

2000-07-06 18:51:11
Subject: Re: Server Tools
From: Tab Trepagnier <Tab.Trepagnier AT LAITRAM DOT COM>
Date: Thu, 6 Jul 2000 17:51:11 -0500
Gill,

I'm no guru, but I've been experimenting with AIX/ADSM tuning for several
months.  Here's where I am...

ADSM 3.1.2.55;  AIX 4.3.2
Our server is a 7025 F50, dual 332 MHz CPUs, 512 MB RAM (low for an ADSM server
but it started at 128 MB).
Nightly backups are about 110 clients + about 8 archive jobs.
ADSM DB is 21.5 GB; DB buffer pool is 96 MB.
Total data on the system is 5.5 TB.

Our system exhibited the same symptoms as yours: "I've noticed that once things
kick in at 8AM
sometimes it takes up to 5 minutes to get a query or web page back."

It looked to me like the AIX VMM was paging out the DB buffer pool pages.
The critical change I made to our server was to raise the AIX VMTune "minperm"
parameter from its default of just under 20% to 35%.
That allowed the "processes" to lock in 179 MB of memory as "permanent" which is
equal to the DB buffer pool plus 83 MB.
Disk paging (in and out) dropped from plateaus of 250 / sec to as few as 5 /
minute.  Response is almost instantaneous.

I made some other changes such as shrinking the size of the individual ADSM disk
volumes and increasing the read-ahead caching, but their benefit has been minor.
I'm still experimenting with the "maxperm" parameter, but have nothing yet to
report.

Hope this helps but please understand that I'm self-taught in AIX so don't treat
any of this as the final word.

Tab








"Gill, Geoffrey L." <GEOFFREY.L.GILL AT SAIC DOT COM> on 07/06/2000 03:10:56 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: Tab Trepagnier/Corporation/Laitram/US)
Subject:  Server Tools




This is for all you AIX guru's out there,

I have no experience with AIX, but learning. I'd like to know if there are
any "built in" tools or other tools I can use to monitor the H50 we have.
We're running 4.3.3 with ADSM 3.1.2.55. I'm curious how memory and CPU are
being hit on performance. I've noticed that once things kick in at 8AM
sometimes it takes up to 5 minutes to get a query or web page back.

I'd also like to know if there is any documentation out there that gives
information as to what kind of load ADSM can handle, when and what kind of
upgrades they recommend based on the number of clients or ADSM capacity.

Thanks for the help,
Geoff Gill
NT Systems Support Engineer
Computer Systems Group
E-Mail:   gillg AT saic DOT com
Phone:  (858) 826-4062
Pager:   (888) 997-9614
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