HELP - disk utility can't repair Mac HD - Data error -69845

EdgemontFarm wrote:

I tried running from the bottom (as directed) which is "Macintosh HD - Data"

While I know a lot of people suggest this......it is better to run First Aid on the hidden Container first. The Container has its own file system and all APFS volumes within that container rely on the container being healthy. Plus Disk Utility automatically runs First Aid on each APFS within that hidden Container.

In fact, one of the error messages you posted actually says it cannot repair the APFS volume because the Container file system has not yet been checked. See this part of your posted First Aid report:

"The volume /dev/rdisk3s2 was found to be corrupt and needs to be repaired."

"unable to perform deferred repairs without full space verification"

"try running fsck against the entire APFS container instead of a volume"

and repeatedly get the same loooong message that I do not know how to copy to paste here or keep the details, but took 13 photos of the screens.

You can copy & paste the extra long text using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

If First Aid is unable to repair the APFS file system after several attempts while booted into Recovery Mode, then that file system cannot be repaired. In that case the only way to fix it would be to completely erase the disk followed by reinstalling macOS & restoring from a backup.

The volume mounts fine and the 1st snapshot check seems fine.

Then starting with the 2nd snapshot it starts a long list of warnings starting with:

"extended attribute (id 951325, name com.apple.provenance)"

"warning:snapshot fsroot/file key rolling/doc-id tree corruptions are not repaired; they'll go away once the snapshot is deleted"

You can probably safely ignore the snapshot errors since like the error message mentions, the errors will disappear once the snapshot is deleted. Usually snapshots are automatically deleted after about 1 or 2 days. Since snapshots are not normally mounted or accessed, there should be no problem.

I didn't know what else to do but just bought a new Mac Studio etc and frankly I'm terrified to migrate because it would seem to me that I would just migrate the same corrupt data over, so I've been scared to even open the boxes and start this process.

File system issues on the old Mac should not affect the new Mac unless you have corrupt files/folders....in that case the corrupt files & folders would be transferred, but you can just delete them since the file system on the new Mac won't be affected. Same thing applies to backups.

EdgemontFarm wrote:

The "1st snapshot" DU Repair says its looking at that seems okay is actually the original Time Machine backup on April 13 back when this shenanigans all started and I had to make a completely fresh TM backup.

The rest are all these you can see (attached) that last was today at 4:00pm. So these are all "new".

Your "1st snapshot" appears to be named as a live snapshot rather than a "Time Machine snapshot" as are all of the others. I don't know exactly what a "live" snapshot means, but it is apparently different. My MBA shows no such "live" snapshot. I can't check my Intel Macs at the moment.

Each of them still says :

"extended attribute (id 951325, name com.apple.provenance)"

"warning:snapshot fsroot/file key rolling/doc-id tree corruptions are not repaired; they'll go away once the snapshot is deleted"

"warning: (oid 0x90391f9) apfs_root: btn: invalid o_cksum (0x0)"

"error: (oid 0x90391f9) apfs_root: btn: found zeroed-out block"

I don't know what any of that means.

There is no way to tell what snapshots these are because the DU Repair doesn't list any snapshot name or date like you see on the list (attached) of actual snapshots.

ALL of the error snapshot messages say the same "id 951325" and the same "warning" numbers.

I have run DU First Aid from Recovery on my MBA M2 2023 Sequoia, and my results are similar to yours. However, I have no reason to believe my snapshots actually are corrupt so I chalk up these errors to DU being unable to properly report and repair TM snapshots. TM backups cannot be navigated and manipulated by Finder without risking corruption, so I make the assumption that DU will not repair what it believes is "corruption" without risking similar damage. TM backups do seem to be delicate in some regards.

You have not indicated that you are having any trouble at all with your Mac nor with any TM backups. In fact, your original post was ❝HELP - disk utility can't repair Mac HD - Data error -69845❞

I think you are seeing normal limitations of DU and First Aid when run against normal TM snapshots, and I don't think you have real reason for concern.

Yes, you'd think that Apple would design safeguards into the First Aid routines, and maybe that just means that DU makes these reports but doesn't or cannot do anything about what it finds re: TM's snapshots. It is well known that First Aid cannot repair a host of drive and directory issues.

I get these same errors in DU Repair whether I am targeting the "Container Disk 1" or the "Macintosh HD - data"

Is that the "Data Volume"?

I would expect the same errors because DU will check those snapshots while running First Aid on the Container.

Yes, the volume "Macintosh HD - Data" is the "Data Volume"

I don't understand how I would migrate from a TM Backup if these snapshots are corrupted. Or how I would migrate from my Old Hard Drive if that has this same problem?

I'm also concerned because I'll be migrating from an intel to a silicon and from Ventura to Sequoia and am worried that I REALLY won't know if something goes haywire and bringing something corrupt would defeat the purpose of buying a new Mac system no?

Again, I don't think you really have a problem here. I don't believe your snapshots actually are corrupted.

When you migrate to your new Mac, you'll use the Time Machine backup drive, not any of these snapshots.

Sounds to me like the drive in the original machine is failing.

Don't worry about migrating a problem over. That won't be an issue.

Migrate the data from the Time Machine backup to the new machine.

EdgemontFarm wrote:

When I run first Aid in Container 3 it looks like its all ok until after it looks at the 1st snapshot... then it has all the same messages after 25 snapshots that the tree corruptions will go away once the snapshot is deleted (I have zero idea how these are deleted!)

But you are mentioning that these snapshots should have been deleted after 1-2 days - it's been weeks. So I don't know what these are (are these from Time Machine?)

It makes me think there is continual corruption and I don't know what or why.

Are they the exact same snapshots? Or were the snapshots deleted and you have errors on the newer snapshots?

You should be able to see the dates of the snapshots in Disk Utility when you view APFS snapshots:

View APFS snapshots in Disk Utility on Mac - Apple Support

Sorry to be a pain but if I transferred corrupt files and folders how would I know this or which ones were corrupt?

No idea. You can migrate from the old computer instead of a TM backup or APSF snapshot.

Are there actually any errors on the Data volume?

Aren't the "snapshots" what Time Machine would be bringing over using Migration Assistant?

You are looking at errors with the APFS TM snapshots on your computer....not your TM backup drive.

I believe the TM app would be manipulating items. I don't know what exactly TM does with these APFS snapshots.

If you are migrating from the old computer, then Migration/Setup Assistant would be using the files on the main Data volume and not any of the TM APFS snapshots unless you specifically selected one of those snapshots.