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Error 69888 couldn't unmount disk - external drive won't erase

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

Posted on Jan 3, 2022 5:37 AM

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I stopped running Hazel, and then I could erase the drive. For some reason, Hazel was blocking the erase and First Aide

Posted on Jan 3, 2022 8:06 AM

4 replies

Error 69888 couldn't unmount disk - external drive won't erase

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