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Level 1

4 points

machintosh disk format was failing

Disk utility was failing with error while formatting machinthosh disk . The error "disk can not be unmounted"

Posted on Dec 4, 2020 12:15 AM

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Level 9

55,880 points

Posted on Dec 4, 2020 8:10 PM

You cannot erase the drive if you are booted from it. To erase the boot drive you need to boot from some sort of external media such as Internet Recovery Mode or a bootable macOS USB installer.

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