Do most RAID 5 adapters that allow hot swap of drives build an array automatically? The reason I ask is because I have a Dell Poweredge 6450 server that is configured with a RAID 5 using three SCSI drives. I had one drive fail on me the other day, and I am going to replace the drive. Would I be able to just swap in the new drive and let the array rebuild itself, or will I have to go into the RAID controller confguration at boot and rebuild the array that way? I just wan to make sure the "Rebuilding" the array is the option that I want, I don't want to build a brand new array. Does rebuilding only get the new drive up to speed with the other two?

The Dell PowerEdge 2300 and 2400 servers that I once used, with the same arrangement as you have -- RAID 5 with three SCSI drives -- did, in fact, do just that. When I received the 2300, I tested it prior to installing the applications by yanking a drive out. It beeped violently to get my attention. I simply replaced the drive and waited 30 or 40 minutes while the array rebuilt, without my intervention. Of course, that's not gospel and yours may be different.

SO adding a new drive to the array is something that I should do when the server isn't being tax by users (at the end of the day).