Cannot use non raid formatted disk to replace a Raid 5 disk volume.
Background to issue:
I have a Raid 5 configuration on my PR4100 with 4x4TB WD Red drives installed as well as a spare 4TB WD Red drive that I want to use a a recovery disk in the event one of my the Raid volumes needs to be replaced. The spare drive was previously formatted as a JBOB disk and will not reformat when installed as replacement of one of my Raid 5. I assume it needs to be reformatted to meet format requirements for a Raid 5 configuration.
What is the disk format requirements for the Raid 5?
Can the format requirements be created using the MAC OS? If not, is their an alternative method using the PR4100 built in functions.