I've had a VPS running Ubuntu 9.10 x64 server, hosting 3 websites of mine for a few months now. This problem has been happening for a while.

Every once in a while, probably every 2 or 3 days, I'll wake up in the morning, and apache won't be responding, no web pages will load.

/etc/init.d/apache2 status, reports that apache is functioning properly. Every time I simply have to restart the daemon and things run fine for another few days.

I thought maybe it was a memory issue, so I lowered the MaxClients in the prefork module from 50 to 30 a few days ago, but the same thing is still happening. My VPS has 512MB of ram, burstable to 1GB, and according to Virtuozzo, there was only one night of high traffic where I even came close to that soft limit.

I've checked my syslog, and there's absolutely nothing in there about apache. I've checked apache's error.log as well, and there's nothing in there that would indicate a problem either.

I know the description of this problem is pretty vague, but whatever info may help diagnose this problem, please, ask me and I'll get the info. I'm lost here... no clue where to look.