[Help] did I need to shutdown ESXi to rebuild my raid

New server, been running about 1 week. I have 6 2tb Sata drives with a PERC6/i controller(unknown model). I have the drives in Raid 50. One of my drives failed(no big deal, it happens) I ordered another one.

I shut the server down, rebooted into the controller, removed the bad drive, and slotted the new one. Rebuild started.

My Question: while the rebuild is happening I cant use the server. Did I really need to do this? Could I have simply swapped the drives and let the machine rebuild the raid while still in operation?