Encountered a new Dell Poweredge server I hadn't seen before today which was beeping. Turned out to be a failed drive in a RAID 5 array as indicated by amber light by drive tray and corresponding failed disk notifier in Openmanage utilty run from Win 2000 server.
Original Raid Info:
3 Maxtor 10k SCSI ultra320 80 pin drives in a Raid 5, top one (disk 0) was failed
I put in the closest replacement I could find which was a Seagate 10k SCSI ultra320 80 pin in place of disk 0 (hot swapped)
The openmanage utility started to rebuild the array, ceasing the beeping. 2 hours later the server was beeping again, this time reporting the 3rd drive (disk 2) failed.
So.. I replaced that with another Seagate I had. (hot swap) still no problems with the OS running.
2 hours later, the rebuild is complete, all drives are green on the indicator, the Openmanage reports all 3 drives online, gone are the Yellow exclamation points and red X's from before, everything looks ok but as soon as the rebuild was compete, again it's beeping.