I have a client with a SBS 2003 SP2 HP ML350 G5 server that was swing migrated from an older server (which wasn't experiencing problems). It randomly locks up under load (during 9-5 business hours), sometimes 2-3 times a day, sometimes it goes two days without needing reboot. Most of the time, the keyboard and mouse become unresponsive and the machine has to be power cycled via power button.
When the server locks up, client computers can still use the server for DNS resolution for Internet browsing, but they lose access to Exchange. Sometimes upon reboot, the server hangs at "Applying Computer Settings" and it has to be restarted again to fully boot.
The event logs don't indicate anything before the server crashes. I have updated all HP drivers. Antivirus is disabled. There is tons of free space on system partition and partition where Exchange DBs live. I ran CHKDSK on both partitions and they both said they fixed minor inconsistencies. Also, Microsoft has had me upload perfmon and perfwiz logs to them and they can't figure it out. Their suggestion right now is to mount blank databases and see if it still happens. And this is the recommendation of a Senior Engineer. Also, they had me run "isinteg s <exchangeservername> -fix test alltests" on Exchange DBs and everything looks normal to them there.
I'm at a loss and I am hoping one of you might have an answer. You guys have been invaluable thus far. Let me know what details you'd like and I'll provide them as soon as I can.