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Question: External Hard Drive won't mount after reformat attempt

I just bought a new external hard drive and was attempting to reformat it from ExFAT to APFS encrypted. The operation failed and now the disk won't mount (thought it still appears in Disk Utility). I have tried to reformat and use first aid but neither will work. Any help or suggestions are appreciated. There is not data on the drive so recovery of files is not an issue.

This is what it says when attempting first aid:

First Aid process has failed. If possible back up the data on this volume. Click Done to continue.


Repairing file system.

Volume is already unmounted.

Performing fsck_hfs -fy -x /dev/rdisk3s1

File system check exit code is 8.

Restoring the original state found as unmounted.

File system verify or repair failed.

Operation failed…

This is what it says when attempting to reformat:

Erase process has failed. Click Done to continue.


Unmounting disk

MediaKit reports not enough space on device for requested operation.

Operation failed…

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Mar 9, 2018 10:36 AM in response to acropoli In response to acropoli

I'm thinking you may not know how to use the newest disk Utility. APFS. forget about the old thinking about partitioning. You'll have three basic sections; Media, Container and volumes. On that new drive just do an erase on the media. After that a container should be created and a volume. If you want more volumes then select + or less then select - First aid run on the volume. The container is a 'bridge' or assist to make partitioning easier than it used to be, if you check on the volume size its large because all volumes created SHARE the space. The partition scheme is only to add so you don't need to go there but once. All volumes added with a system installed are bootable. APFS is nice.

Mar 9, 2018 10:36 AM

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Question: External Hard Drive won't mount after reformat attempt