Hi
We use a Dell PowerEdge server which has SCSI drives. When I added an extra disk I had to use the SCSI bios utilities (by pressing Ctrl+A) that display at boot time. I cannot remember the exact procedure, but I had to tell the BIOS SCSI RAID utility that the drive was present, reboot, and then use a second SCSI RAID utility to format it.
Both the utilities could be accessed during the POST procedure.
I would really recommend that you look at any documentation that came with your server, or, preferably, you get exact instructions from the web. I ended up calling Dell's Tech Support who were extremely helpful.
Good luck