Initially purchased with an 80GB ATA hard drive it was upgraded to a 250GB ATA drive and will be upgraded to an ATA mirroring controller with second hard drive.
The motherboard is a Supermicro P4SCE. BIOS version is Phoenix Technologies, LTD.6.PG.12/21/2003.
On February, 13th 2006 the server broke down and led to a breakdown of Wikimedia services for several hours.
The RAID controller is a 3ware 8006-2LP half-length, half-height SATA RAID controller with two ports for two drives total, supporting RAID levels 0, 1, JBOD. Manuals are here, see the 8000 series. Drivers are here.
Notes from a phone call with 3ware resemble: look for lib/modules/klernel/drivers/scsi for the 3ware 3x.xxxx.0 (3w.80006.0 or perhaps 3w.8000.0 if no 8006-specific version) driver and use insmod. Should be similar for all Linux flavors. Get the latest driver from the web site.