It depends on the FW version.   If you are running a recent version, the tech can help you mirror the drive instead of doing the long process of rebuilds.  Especially if you are running RAID5,  this puts your data at greater risk if you do the multiple rebuilds.   So if you are running current fw, contact support again, and they can help you with that process. 
I'm getting 3 replacement drives from Dell to replace healthy drives whose firmware can't be updated (the 3 current drives are all replacements for failed disks we've had in the last few years). I expect the new drives today, but I forgot to ask the storage tech the proper procedure when I was on the phone with him yesterday. One of the current drives is the spare and the other 2 are hot. I'm guessing that I: - replace the spare first and check the EQ - I don't expect any rebuild time, but is there anything else that might take some time? - replace the first hot one and wait for full rebuild, which should finish over the weekend - replace the second hot one Am I missing anything? Thanks.
Replace multiple drives on PS5000e