Cannot erase broken partition

Question

Level 1

4 points

Cannot erase broken partition

I left an external hard drive attached to a 2021 Macbook Pro (running Ventura 13.4.1) overnight to complete a backup, and in the morning I saw a message saying that the Time Machine partition could not be repaired and needed to be wiped to work again.

The computer was plugged in, and I'm sure I had a 1/2 power outage during the night (although I don't think that would affect a laptop). Anyway, I've tried SOS, I've tried wiping/initialising, but I can't seem to do it because I can't disable the disc. The second partition seems instead to be working fine.

The strange thing in Utility Disk is that I can't see the main drive icon. I used to be able to see the main drive name with a drop down list of partitions. Now I can only see the partitions.

Is there anything I can do to try and wipe the partition and re-initialise it? I can't even wipe the whole disc because I can't see the main drive icon.

Thank you in advance for your help.

MacBook Pro 15″, macOS 12.2

Posted on Aug 3, 2023 4:37 AM

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Answer 1

Tesserax

Level 10

159,088 points

Aug 3, 2023 9:44 AM in response to roberto-r

In the Disk Utility, change the View to "Show All Devices" to see if this will allow you to see the "main drive icon."

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Answer 2

MrHoffman

Level 10

152,179 points

Aug 5, 2023 9:35 AM in response to roberto-r

Boot into Safe Mode, log into an Admin user, shut off Time Machine, launch Disk Utility, connect the drive, and erase it entirely.

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Answer 3

MrHoffman

Level 10

152,179 points

Aug 5, 2023 10:10 AM in response to roberto-r

-69888 is a failure to unmount.

TM appears welded to that disk.

Build a bootable installer, boot that, and use Disk Utility to entirely erase the culprit HDD.

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Answer 4

Tesserax

Level 10

159,088 points

Aug 5, 2023 9:21 AM in response to roberto-r

Have you tried simply powering down your computer, and then, physically disconnecting your LaCie drive; then, while it is still disconnected, power-up your computer?

This should "remove" the external drive from the Disk Utility and you should now "see" your Mac's system drive properly.

You can then re-attach the LaCie to see if you can erase/delete the TM partition.

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Answer 5

MrHoffman

Level 10

152,179 points

Aug 6, 2023 10:43 AM in response to roberto-r

roberto-r wrote:

Just to clarify - do you mean to create a bootable installer on another HDD and then use that to erase my current external drive? Also, I have already unlinked that Time Machine link, so that shouldn't be an issue.

I mean to boot from another copy of macOS on a bootable flash drive, to launch Disk Utility within the installer, and to try to use that to initialize the errant HDD. This eliminates any activities involving your primary copy of macOS.

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Answer 6

roberto-r Author

Level 1

4 points

Aug 5, 2023 2:17 AM in response to Tesserax

I did it and can indeed see it now. However, I cannot erase it because it says it is 'in use'. I can't even eject it for the same reason. I also tried stopping the mds_stores process but it just restarts and the issue is not resolved

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Answer 7

roberto-r Author

Level 1

4 points

Aug 5, 2023 9:30 AM in response to Tesserax

I did. Every time I re-attach the LaCie, it shows up again and a few minutes later a message prompts me that the hard drive is damaged. At that point, I cannot do anything on disc utility because it will tell me that the hard drive is being used at the moment.

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Answer 8

roberto-r Author

Level 1

4 points

Aug 6, 2023 12:12 AM in response to MrHoffman

Just to clarify - do you mean to create a bootable installer on another HDD and then use that to erase my current external drive? Also, I have already unlinked that Time Machine link, so that shouldn't be an issue.

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