On 3/7/08, Scott Silva <ssilva at sgvwater.com> wrote: > on 3-6-2008 3:58 PM Scott R. Ehrlich spake the following: > > 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? Hi there, Minor point: Rather than go for a RAID 5 with a hot spare you are better off going for a RAID 6 array using the 4 discs if your hardware supports it. If your RAID 5 has a disk failure then has another whilst it is rebuilding using the hot spare then your data is b0rked whereas with RAID 6 you can tolerate 2 disk failures and still access the data. You lose the same amount of capacity that you would have with the RAID 5 + hot spare set up that you are considering. mike