My external backup drive won’t let me erase it. I get Error 69888 couldn't unmount disk.
When I try First Aid, I get: "Unable to unmount volume for repair. : (-69673)"
Any ideas for erasing and reformating this drive?
iMac 27″, macOS 10.15
Disk Utilities >> View >> View ALL attached Drives.
Choose the Upper Most Drive By Manufactures Name of the External Drive
That is the drive to Erase and format as APFS with the GUID Partition Map.
I stopped running Hazel, and then I could erase the drive. For some reason, Hazel was blocking the erase and First Aide
Unfortunately, I had already tried that and got the error messages.
Thank you for the suggestion.
Have you tried Dismounting any volumes listed below the Physical Drive name and then choose the Drive by Name ?
Disregard above as you solution just arrive Hazel
Good work and bravo
Error 69888 couldn't unmount disk - external drive won't erase
