my mistake, the raid only used 3 disks. Another one is a  hot spare. That is the reason why the insert new disk it will not rebuild
We have a 2950 server with perc5i Raid5.  Yesterday, one of the disk shows failed in the Dell openmanager. 1. I use a same size new disk to replace it. 2. But it shows foreign in openmanage.  It is a new disk never opened. Usually it will show rebuilding.   3.Then I restart the server, now it shows ready in openmange. Still not start rebuilding. Any advise?
Need help for raid5 rebuild on 2950 perc5i