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shelbylerner

macrumors newbie
Original poster
Jun 3, 2021
1
0
Hello! Not sure if anyone can help me here but my MacBook finally updated to Big Sur 11.4 this afternoon by itself and when I went to go turn it back on, only two of my three external drives were visible on my desktop. My third (And most important drive) was visible but greyed out in disk utility and said that it was unmounted. This drive in particular is a WD Elements 4 TB drive that I've been using for the past three or four years and there is A LOT of valuable information on it that I cannot loose. My other two drives are also WD elements but I purchased them only recently. The problem drive is the one that I use as my time machine backup for my Mac.

I have already tried:

-Turning my computer on and off (a few times).

-Running first aid, all I get is the "First Aid process has failed. If possible back up the data on this volume." error message.

-Trying to remount it, I get the "Could not mount “My Book”. (com.apple.DiskManagement.disenter error 0.)" error message there.

-Plugging it into another Mac that is running a different OS (theirs was running Mojave) and it still didn't work.

I can hear it turn on and the fan spinning just like normal but it just isn't re-mounting to any Mac computer. Please is anyone that has a solution for this, let me know!! There's too much important material and work on here to just be erased.
 

gilby101

macrumors 68030
Mar 17, 2010
2,921
1,616
Tasmania
It can be helpful to have the output of the Terminal Command: diskutil list

-Plugging it into another Mac that is running a different OS (theirs was running Mojave) and it still didn't work.
If it had been formatted via Big Sur's Time Machine, I suspect that Mojave might have trouble mounting it. But if older Time Machine (HFS+ format) Mojave should mount it.
Running first aid, all I get is the "First Aid process has failed. If possible back up the data on this volume." error message.
Did you run first aid on the Drive, not just the volume?

The problem drive is the one that I use as my time machine backup for my Mac.
In that case, I would just get a new HDD and establish it as the Time Machine destination with a new backup.
 
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