So I've learned a valuable RAID 0 lesson, and it fortunately was not a major catastrophy. I got lucky, and had a workable-enough backup on tape to make the user who needed some data happy. Now, from the OS side, LVM is an option. Say the RAID controller only allows hardware striping or mirroring for logical volumes, but I want to use more than two disks, and I don't want the RAID 0 problem again. When I get a replacement disk and build the system from the ground up again, I could, conceivably, use hardware RAID 1 for the OS on two disks, and CentOS 5 64-bit's LVM for software RAID 5 (or maybe 1+0 if available) on the remaining for 4 disks, maybe 3 disks as active and the 4th as a hot spare? I've never had much faith in software raid, since it is not hardware-based, and there would be a performance hit, but in this case, it could be an option. Insights from the OS-created RAID experience welcome. Thanks again. Scott