Time Machine Error and Disk Utility

As I understand it, the disk error happened before you launched Disk Utility and before you erased the local snapshots.

The reason DU could not repair the disk is because it cannot repair its own startup drive. You'll have to restart the Mac in recovery and launch DU from the macOS Utilities screen. Only then can DU's First Aid routines repair any directory damage that might have happened on the boot drive.

The guidance you found for deleting local snapshots is correct. But I don't believe the snapshots to be the problem. Yes, they can occupy space on the drive, but otherwise are benign and even helpful to have available if short term data recovery is necessary.

• What exactly were you trying to do when you got that very first error message?

• What problem(s) did you encounter?

If you can restart your Mac in recovery, you can try to repair the startup drive from there. If DU discovers any problems, that is how you may be able to correct them. Run First Aid on both the system volume "Macintosh HD" and the data volume "Macintosh HD - Data". Then also on the container and finally the drive device itself.

How to start up from macOS Recovery - Apple Support

Repair a storage device in Disk Utility on Mac - Apple Support

Kevinwal wrote:

First thank you both for your help. It is apprecaiated.

You're welcome.

I think the Log Report I sent was the first time I ran Disk Utility while in the startup volume. I will try again but if the "Data Disk Lock" is not repairable by that do I need to do that? An dhow do ou suggest I correct that error message.

Once you properly enter Recovery mode and run Disk Utility's First Aid successfully, that would hopefully fix for the problem.

Data Disk is formatted as follows:

https://discussions.apple.com/content/attachment/c758ab39-b95e-471d-83f0-518b2d48a8f5

This format is fine and I see that the volume "Data" is not a Time Machine volume but is a component of a normal macOS install.

However... the normal name of this volume is "Macintosh HD - Data". The fact that it is now simply "Data" says that either you have changed the name or there was some problem with the initial macOS installation or an update or upgrade.

• Did you rename the volume at some point?

• How long have you had this Mac Studio?

You mentioned it had "File Vault" on it, but I certainly don't have that turned on and don't see how to check it if it is. File Vault is NOT turned on in Settings.

Yes, I assumed that, incorrectly, because the icon on the error message is the same as that for FileVault.

For the rest of this troubleshooting I suggest that you do all of this in order:

• Disconnect all other external drives and volumes.

• Make sure your Time Machine backup is up to date.

• Restart the Mac in safe mode. Safe mode does disk repair, clears caches and does other housekeeping.

It's not difficult and it often corrects weird Mac behavior. Guidance is here: Start up your Mac in safe mode - Apple Support

• Lastly, restart the Mac normally and see if the problem remains.

Come back here and let us know the result.

Kevinwal wrote:

Ok, I have forgot to mention that my backup disk is an "externally attached" drive. (Apologies to Owl-53)

This all started with the error message

https://discussions.apple.com/content/attachment/d4b80324-eab0-4da0-ac28-7866f96ec869

It doesnt say the error was on the Time Machine External DIsk so I attempted to fix this by running DiskUtility in Recovery Mode on the Macintosh HD Data Disk. Not the Time Machine Disk

It appears you were not in Recovery Mode when you ran Disk Utility. The first line of text in your DU repair results pic indicates you were operating from the startup drive. You might wish to try again.

How to start up from macOS Recovery - Apple Support

That appeared to work but repair message indicated that many SnapShots could not be repaired. Some search indicated that I could delete them. Which I did.

Nah, it didn't work, and AFAIK, Disk Utility doesn't repair Time Machine snapshots.

Yes, you can delete local snapshots, but they are not likely related to the problem with unlocking "Data". Be skeptical of whatever "instructions" stated they were.

I received the error message about "Unlocking" again this a.m.

It appears the disk "Data" is protected with File Vault.

• How is that disk formatted?

• What do you use "Data" for?

• Is it a Time Machine backup drive?

If it is a TM backup drive, then refer to user @Owl-53's first reply to your original post above.

They "suggest you reformat the drive..." I agree. Do that and start a fresh Time Machine backup set. It's probably the best and easiest option.

OP wrote " it appeared related to Backup Snapshots. I deleleted them which I thought would solve the problem "

Sorry but having done what appears to have been done " Backup Snapshots. I deleleted them "

It is never suggested to muck around with TM Backup Snapshots

Deleting Snapshot may have corrupted All the Snapshots in the drive

Suggest your Reformat the drive - Yes everything will be lost forever

The info from Apple is correct

Sorry, I understand you were trying to delete TM Snapshots that were on the External Drive