Re: Diagnosing performance problems

From: Vikas Agnihotri (fornewsgroups_at_vikas.mailshell.com)
Date: 12/04/03 

Date: Thu, 04 Dec 2003 10:38:30 -0500

On Thu, 04 Dec 2003 10:08:00 +0200, Toomas Soome
<Toomas.Soome@microlink.ee> wrote:

> pmap. you should not worry about this too mutch -- it's reserved space
> most likely and since you have plenty of free RAM (as you can see from
> top), it seems to be no problem here.

Well, not really.

load averages: 0.97, 1.10, 1.29
286 processes: 283 sleeping, 1 stopped, 2 on cpu
CPU states: 38.6% idle, 15.0% user, 4.9% kernel, 41.5% iowait, 0.0% swap
Memory: 1024M real, 63.0M free, 911M swap in use, 1.7G swap free

swap -l:
swapfile dev swaplo blocks free
/dev/dsk/c0t0d0s7 32,7 16 2049696 1809472
/dev/dsk/c0t1d0s7 32,15 16 2049696 1810976

swap -s:
total: 875520k bytes allocated + 73872k reserved = 949392k used, 1793496k
available

Only 63M free out of 1G RAM is a little worrying, no?

When I run this on other machines, which are basically idle, I get more
than 300M free. Who is using so much memory? As I said in another post,
since I am using Oracle which uses a large 250M shm segment and all
processes attach to it, the usual tools to answer this question are
failing me since each Oracle connection shows as using 250M for a grand
total of some meaningless number.

Questions:
1. Is the 911M swap really in use? I doubt it. But then why is so much
swap space show as "used" in both top and 'swap -s'?
2. Why is so little memory free? Could that cause the high iowait % seen
in top?

> my suggestion -- download SE toolkit and run virtual_adrian, it will
> tell you loud and clear whats wrong:)

Where can I get the latest version of virtual_adrian? There seem to be
many copies floating on the net

Thanks