Several issues actually:
- This is a drive which is not supported in this machine. Never tested with it, the firmware mismatches and so on. You can ignore this, since the server is long since EOL anyhow, so who cares about warranty, support, and whatever this machine does (because who would use an EOL server for production, right?)
- You haven't mentioned how you are connecting the disk. If you're connecting it directly to the SATA ports on the motherboard, it is quite possible the onboard SATA controller is disabled and needs to be turned on in the BIOS.
- If you're trying to put the drive in a caddy and simply use it in a hotswap bay, it will not work at all. Chances are the backplane is connected to a RAID controller (SAS 6 or PERC 6 in this case IIRC) and the controller is built for SAS, not SATA. You might get it to work if you find an interposer, but that's not an easy task these days.
- Alternatively, the backplane might not be connected to anything, which means a missing controller and the disk just hanging there doing nothing.
[offtop]I would ditch this server completely and get a modern machine, a current enough i5 desktop can outperform it, and waste less power. The 2950 used to be a really cool device in 2007, a nice machine in 2010, and an old, useless rag in 2015. C'est la vie. [/offtop]