You must get a drive that 'belong' in your system. I had replacement drives sent to me (under support) they showed up in the older drive caddy for 'Xyratex' enclosures I swapped the drive caddy with the failed SC200 drive. The Compellent did not recognize this disk. bad part# error if I remember correctly. they sent a replacement that came in a Dell drive caddy and it worked as expected. Drive firmware?... Any old drive will not work. (if they did I'd be buying the Seagate Constellation 3TB 7.2k drives online for $300 instead of close to $1000 from Dell!)
I was wondering if anyone could assist me with an issue with my compellent san. I had a hard drive crash and purchased a replacement, when I put it in it sees the drive but it shows up unassigned. When I go to assign it to the folder I get an error message " An error occurred trying to mark as spare the disk object (identified as ") Unable to spare Disk 24, Disk unclassified. Is there something I am missing? This unit is a bit older and dell no longer supports the drives. I'd appreciate any suggestions on this. Thank you Bryan 
Compellent SAN - Replacement Drives Unassigned