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macOS Won’t Boot: “Macintosh HD - Data” and “Update” Disks Appearing

Hello,


I’m facing an issue with my Mac where macOS no longer boots. Upon checking in Disk Utility, I see the following:


1. Macintosh HD - Data: This volume appears below the usual Container disk2

2. Update: A partition labeled “Update” has appeared, which I’ve never seen before.


Here’s what happened:


• My Mac was performing a macOS update, but something seems to have gone wrong during the process.

• After restarting, macOS no longer boots, and I’m stuck.


I’ve tried the following so far:


• Booting into macOS Recovery and running First Aid on both Macintosh HD and Macintosh HD - Data. First Aid completed without any reported errors.

• Restarting in Safe Mode, but the system still doesn’t boot.

• Checking Disk Utility, where I noticed this mysterious “Update” partition, which I assume might have been created during the failed update process.


I’d appreciate guidance on how to:


1. Remove the “Update” partition safely.

2. Restore macOS to boot properly without losing the data on Macintosh HD - Data.


See screenshot attached.


Thanks in advance for any advice!

Posted on Nov 23, 2024 8:41 AM

Reply
4 replies

Nov 23, 2024 9:16 AM in response to rosner

During an Upgrade or Update, the iMac can go to black screen and restart multiple times.


If the iMac lost power or if you became inpatient and interrupt the Update...?

Then use macOS Recovery to try and reinstall the macOS over the top of the current version.

If that doesn't work, then you need to Erase, Reinstall and then Migrate from your Time Machine backup.

Nov 24, 2024 1:16 AM in response to den.thed

Thank you for your response. Unfortunately, I wasn’t the one working on the iMac when the issue occurred, so I’m still trying to figure out what happened.


I understand you believe reformatting is the only solution, but I know someone experienced in regaining access to Macs who has successfully done this for others I know. Unfortunately, they’re currently unavailable as they’re traveling for a few weeks.


If you have any alternative suggestions, I’d be happy to hear them.

Nov 26, 2024 1:56 PM in response to rosner

One of my organization's co-workers just tried an OS update patch which failed to install leaving their laptop unable to boot to the internal SSD. Simply reinstalling macOS over top of itself as suggested by @den.thed fixed it. Just make sure to boot into Recovery Mode using Command + R so you are reinstalling the same OS you had before.

macOS Won’t Boot: “Macintosh HD - Data” and “Update” Disks Appearing

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