The following hints, tips, ideas and unsubstantiated rumors may help you with this quest. IDE disks can fail in such a way that the failed disk on an IDE ribbon can also prevent the good disk on the same ribbon from responding, thus making it look as if two disks have failed. Since RAID does not protect against two-disk failures, one should either put only one disk on an IDE cable, or if there are two disks, they should belong to different RAID sets. SCSI disks can fail in such a way that the failed disk on a SCSI chain can prevent any device on the chain from being accessed. Thus, no two disks on the same SCSI chain should belong to the same RAID array.
Similar remarks apply to the disk controllers.
Don't use the same brand or model number for all of the disks. It is not uncommon for severe electrical storms to take out two or more disks. Cheap disks often run hot. If anyone gets this working, let me know. Always use an UPS, and perform clean shutdowns.