I have this machine set up as a Postfix/Spamassassin mail relay server for our LAN (125 users). When it works, it kicks serious *ss. The problem is it crashes (completely) every couple of days under load. The error message in /var/log/messages reads

[Kernel] Unable to handle page request.
and then a whole bunch of gibberish.

The machine specs are as follows

p-II 266, 256mb ram, 10Gb hdd, two nics (one 3com, one lynksys isa), and a slim installation of Redhat 9 running only Postfix, Spamassassin, and Iptables as services.

Is this indicative of a memory issue? Or is the machine just too old to serve in this capacity?

How large is your swap partition? It almost sounds like the kernel was trying to read a page from memory, but an error occured in the read/write process. I'm not sure what kind of requirements the apps that your running need, but I would think that 256 MB would be a wee bit on the small side for any app that is serving 125 users. Any chance you can post what the bunch of gibberish is under the error message?

slight

My swap partition (created automatically) is 512mb, approximatly twice the size of the physical ram. It does scream memory problem.

Try running Memtest86 on it and maybe you'll find a memory issue. Another diagnostic tool I would suggest is Gkrellm. Even if you are not running X on the server box I think you can run Gkrellm on it and then connect to it using another machine running X.... at least this would give you a real time look at memory usage and swap usage.

slight

I will give that a shot right now. Thanks a lot for the advice and the link. Hope this works. Spamassassin is really cool.