About 10 seconds after I started this thread, I remembered a long discussion about RAID, SATA, etc., 2 or 3 months ago. I think that Feizhou (?) strongly recommended going with Software RAID in CentOS. I will search for that and do a lot of reading. RAID 1 for mirroring is what I want. Lanny
Whoa there!
Hardware raid + battery backed up memory cache in raid 1,10 mode is hard to beat with software raid and hardware raid offers data integrity guarantee beyond software raid.
If you were planning a huge array especially a raid5 array, then software raid may be better. Hardware RAID cards all come with memory caches now so their throughput is no longer limited.
Another route you can go is getting a PCI/PCIe/PCI-X BBU RAM/NVRAM card to put an external journal on to speed up fsync performance for filesystems like ext3 over software raid since these cards can go beyond 1GB of memory unlike hardware raid cards that usually max out at 256MB.
Software RAID is also good if you need to be able to transfer the disks to another box that does not have a hardware raid controller or the same controller.
Weigh these in your decision. :-)