Can't erase Mac HD to do a Time Machine restore

Question

Can't erase Mac HD to do a Time Machine restore

I have a 2011 MBP running Mavericks and Windows 8.1 in BootCamp.

I blame a windows utility "MacDrive 9" for corrupting my Mac HD. I was working with a file on the drive through Windows and got an error. Later, when trying to boot into OS X I got only a gray screen.

I booted the Mac into the 10.9 recovery partition and ran disk utility. It said the Mac HD partition could not be restored, erase it and restore files.

Fine, but when I highlight the partition and click "Erase" it just says this disk can't be erased. I've never seen that before.

The Windows partition works fine, and I am writing this in Windows. How can I resurrect the Mac partition? I have a Time Machine backup.

MacBook Pro, OS X Mavericks (10.9)

Posted on Dec 7, 2013 5:58 PM

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Answer 1

Best reply

mende1

Level 10

93,538 points

Dec 7, 2013 10:27 PM in response to Maxwell Edison

What MacDrive did was probably to corrupt the OS X partition, and what it is worse is that you have got Boot Camp, so it may be possible that OS X Recovery may not let you erase the OS X volume.

Try to start up in Internet Recovery (hold Command, Option and R keys while your Mac is starting) and try to erase Macintosh HD again. If you cannot, choose the hard drive at the top of the Disk Utility's sidebar, go to Partition tab and erase the whole hard drive.

Finally, close Disk Utility, select the option to restore a Time Machine backup and follow its steps.

If you cannot erase the OS X partition with Disk Utility, do not worry. Try to restore the Time Machine backup directly, because it will erase the OS X partition

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Answer 2

Dec 8, 2013 6:34 AM in response to mende1

I have booted from Internet recovery. I launch disk utility but I cannot format the Mac partition (it's greyed out, unmounted)

So I want to format the whole disk. Click the disk's name, format. This hangs endlessly with an "unmounting disk" progress bar and I need to quit DU. It seems the Boot Camp partition refuses to unmount so that the disk can be formatted.

At this point all I can think of is replacing the physical hard drive. Any ideas left to try?

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Answer 3

Eric Root

Level 10

684,027 points

Dec 8, 2013 1:24 PM in response to Maxwell Edison

Back to Internet Recovery/Disk Utility. Select the Bootcamp partition, then try to unmount it using the Unmount button at the top (4th from left side).

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Answer 4

Dec 8, 2013 6:54 PM in response to Eric Root

These are all excellent suggestions. Unfortunately none worked this time. I bought a new hard drive, replaced the old one, did an internet boot and restored from Time Machine.

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Answer 5

Dec 23, 2014 12:34 PM in response to Maxwell Edison

i had read somewhere when i had this problem that youre supposed to uninstall the bootcamp to do this properly. Theres an uninstall process you must follow.

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