On Thu, 10 Apr 2003 14:12:28 -0400
Guillaume Gilbert <guillaume.gilbert AT DESJARDINS DOT COM> wrote:


> This is at 2:00pm today. I don't really have a performance problem
> (atleast I hope not...).  Expiration runs between 1 and 2 hours
> examining over 4 million files, deleting between 100,000 and 500,000.
>

see above for a hint....

> I also have a smaller TSM server running on the same machine.The
> database is just under 1 gb and the bufpoolsize is at 256000 and I
> can't get the cache hit percentage over 97.
>
> So, are the vmtune settings really that bad? I am not a AIX sysadmin
> and haven't quite understood all this vmtune thingy.
>
> Any help or recommendation will be appreciated.
>
> Thanks in advance
>
> Guillaume Gilbert
> Storage Administrater
> CGI Montreal
>


So why bother, cache hit % such or so, vmtune this and that?

TSM seems to be doing fine, you get expiration done, no backups lasting
longer than acceptable...

I wouldn't think of tuning a system that is doing the work that needs to
be done in the time it needs to be done in, not a second. There's no
use, the work is getting done. You're not running behind on backups or
expiration.

Now _IF_ you were having problems with performance, the cache hit %
_might_ give you a hint. It's just that, a tool to see if that is the
problem. Anyway 99% hits is very high, nobody with a reasonable busy
server gets that high, and with db disks as fast as yours, you don't
need to, it's a complete waist of time and money to even try.

So my advice is, don't bother. Check to see if any backups run longer
that acceptable on a regular basis, check to see if you get your job
done. _IF_ you ever see eg. expiration or backup time growing towards
unacceptable values, then is the time to worry, but only then, for now,
time is probably spent better on other things...

--

Remco