Blackseicento,  Normally a rebuild will take up to about 24hrs, depending on the size, to rebuild. With it sitting for 3 weeks it sounds like there is an issue. Now to start, are you using OpenManage Server Administrator to see rebuild progress? If so the drive may have already rebuilt, but OMSA is misreporting it. If you haven't yet, restart OMSA and it's services. After that then restart OMSA and verify if the status still shows rebuilding. If it does, then reboot the server to the raid controller and verify the Virtual Disks status, as well as the physical disk you replaced. Let me know what you see. 
Hi All,  I have a T300 with 4x 136GB SAS drives on a SAS 6/ir adapter, 2x in RAID 1 and 2x independent. A while ago one of the disks came up with 'Predicted Failure' so I cleared one of the independent disks and then in OMSA set it as a global hot spare. After a minute or two it's status changed to 'Rebuilding'.  Unfortunately, it's been sat on 'Rebuilding' for about 3 weeks now and I'm a little reluctant to reboot it like I always do once a month.  Did I miss a step or do something wrong? Do drive rebuilds take this long? Cheers, Dan
PowerEdge T300 RAID 1 drive replacement stuck on 'Rebuilding'