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degraded RAID 5 volume will not mount

New Member

I am running 5.8.4 XT on Catalina.  I have a RAID 5 4*5 TB in an OWC TB4 enclosure, with one missing disk (failed) and one out-of-sync disk.  I am unable to rebuild or add a replacement disk to the volume due to the out-of-sync disk - fine.  I am ready to make a backup and create a new clean volume with certified disks.

However, I am also not able to mount the RAID 5 volume.  It says it is mounting, then immediately dismounts.  No message in the log as to why.  Any hints here?

Tech report is attached.

Thanks - 

Topic starter Posted : 21/01/2022 5:45 pm
Member Admin

MacOS attempted to repair the volume after an unclean shutdown. It failed and left the volume marked as unmountable.


You can use Disk Warrior to repair the directory, it can fix it in place.

Or you need a recovery program, like Disk Drill, or R-Studio, to recover the data.

Its possible it may mount again, as macOS auto repair runs every mount attempt, but it is not likely.

Posted : 21/01/2022 11:44 pm