So, the machine is a Dell Precision Workstation 690.
It has an LSI SAS 5/iR integrated controller that, when the computer was working initially had RAID configuration though it was only utilizing one drive.
The drive started to slow down severely so, fearing the worst, we cloned the drive over to a newer 2.5 TB drive. We popped it in and had no luck in getting the drive to come up. Trying to reformate/reinstall on said drive resulted in a reboot cycle that was endless after the formatting was done.
We've tried changing all BIOS options imaginable, even tried turning off the adapter and still no dice. Honestly we'd like to forego the RAID option all together since we have other means of backing up and just don't have a need for it right now. If we HAVE to make a RAID that'd be okay, I guess, though we've had no luck in creating an Integrated Mirror volume through the controller. Once we go into the configuration option there's no drives to select and this is with anything we've thrown at it.