Re: Strange System Behaviour

From: Bill (bverzal_at_komatsuna.com)
Date: 05/27/04 

Date: 27 May 2004 10:45:03 -0700

colingresty@yahoo.co.uk (ColinG) wrote in message news:<8fe85d6d.0405270151.3b07063e@posting.google.com>...
> We have a system that is exhibiting strange behaviour.
> I don't know a lot about IBM systems, so appologies for the woolly
> identification.
> The machine is an IBM and has been variously described as an RS6000, P
> series and H80.
> It is running AIX 4.3, has the latest microcode updates, latest
> firmware updates.
> It is dual processor, has 4Gb memory, around 400Gb of disk attached to
> SSA Cards.
> Typical user count during the day is 750 telnet users running an ISAM
> based application.
>
> The problem is that three times in the past year the system has slowed
> to a point where all telnet sessions die, and even the console cannot
> be logged into.
> Interaction has stopped completely, yet the machine will respond to
> pings.
>
> No error logs of any kind are generated, and the system doesn't even
> log the fact that the power switch has been pressed (the only way
> out.)
>
> If anyone has seen this before, I would be extremely interested in
> hearing their experiences.
> Our support vendors have absolutely no idea what is going on since
> there is no diagnostic trace left.
>
> thanks
> Colin

As much as you have provided many details, the possibilities are quite
endless. Do you resolve the problem with a reboot ?

It could be many things from a I/O bittleneck, a memory leak in the
application, a true kernel panic/hang ... ... ...

Honestly, without some good forensic investigation and evidence, you
might be hard pressed to determine the cause.

BV