I have an interesting problem. I am trying to build a new server that uses RAID 5. Here is a break down on components:

Tyan 2505T Mobo
1Ghz P3 in socket 0(only running single processor right now)
512 MB
Adaptec AAA-131U2 RAID Controller
3x Seagate 18.2GB 10K Rpm SCSI drives (for data)
Western Digital 20GB IDE (for OS)
Intel 10/100 Pro NIC
LG IDE CDROM
400W Power supply
Windows 2000 Server

Well this is what is happening. When I configure and write zeros to the array no problem. Everything works great. The array is the correct size and functions fine. If I reboot however whatever SCSI drive has the lowest ID # drops off the Array. So, once ID 0 is gone the array goes critical because only 2 drives are functioning on the array and there is no redundancy. The drive with the lowest ID now appears as a drive separate from the array.

Here is what I have tried. I have tried to change the ID # on the drives to see if it was a faulty drive but it is always the lowest ID # and not a particular drive. I replaced the SCSI cable with another cable that I have on another functioning server. I have replaced the AAA-131U2 with another AAA-131U2 from another server. The other server is identical with the exception that it has dual 1.13 P3, 1GB RAM and runs RAID 0 with no problem. I have tried to run RAID 0 rather than RAID 5 just to see if it would work. I have flashed the motherboard BIOS. I have delayed the start of ID 2 in case the three drives were trying to draw too much power when they all spin up at once on power on.

Thanks for any additional ideas.