You can reboot once the rebuild starts. You may want to make sure it reaches 1% but it isn't required.
Hello Community,   I have PE R510 server with PERC H700. 4 disks are configured RAID5 and now 1 disk is in Predictive Failure state, flashing green and amber. I have exact same spare disk, but I'm not sure how to change the failing disk, because I never perform such task before. Should I just pull the disk out and put a new disk in while an operating system (FreeBSD) is running on the server? Or change the disk when server is PERC BIOS (Ctrl+R)? Maybe shutdown the server and change the disk?   Please help.   Best Regards, Bat
PE R510 with PERC H700, 1 disk from RAID5 in Predictive Failure