Go to Virtual Disks page and delete the single-disk volume. It should then show under Physical Disks as Ready, then you can assign it as a hot-spare to start the rebuild into the RAID 10.
Hi, yesterday i change a failed disk on my poweredge T310 with RAID 10 configuration composed by 4  SAS 15K 278GB disk. On first reboot after i changed the disk, the perc bios ask me to import (F) configuration raid or entry Raid (utility), I choosed F. My sbs 2008 start normally but the replaced disk in windows apper like a new disk so my RAID 10 is alway degraded. On server administrator console now i see 2 virtual disk (1 RAID 10 and 1 Single DIsk), on virtual  disk i can do some operation (delete, Assign/unassign hot spare,rename,change policy,replace meber disk). I can i solve the problem and rebuid my raid 10 Thanks a lot Matteo
RAID 10 DISK FAIL