Disk Utility reports missing resource fork in snapshot files and beach-balls during First Aid on Container

Do not attempt to run First Aid on the snapshot files. There is nothing to be concerned about in that regard.

As for running First Aid on your container: to properly verify and repair the startup drive, you must be booted in recovery mode. Repairs cannot be made to the startup drive while it is live (currently in use).

How to repair a Mac storage device with Disk Utility - Apple Support

I would be a bit concerned if you cannot run First Aid on the Container while booted into Recovery Mode. However, like @D.I. Johnson mentions, errors in the snapshots should not affect anything in the OS. Errors or an inability to scan the Container is troubling because the Data volume is within that container structure. Have you tried running First Aid on the physical SSD in case there is a partition issue of some sort?

Are you also booted into Recovery Mode when you ran First Aid on the Data volume?

What version of macOS are you booting into when in Recovery Mode and which version of macOS is installed on the boot drive?

If your Mac is running fine other than the issue with the First Aid scan, then just ignore those errors for now. Depending on your backup software being used & its settings, those backup APFS snapshots should be deleted automatically at some point. For TM it is generally 24-48 hours assuming the backup drive is always connected. If those backups have been transferred to external media already, then you can delete those APFS snapshots to see if that resolves anything with the Container.

Also, what is the exact model of your Mac? You can get this information by clicking the Apple menu and selecting "About This Mac".

Mike Harrison wrote:

Thanks for your reply.

I'm on a 2023 Mac mini M2 with 8 GB RAM. The boot drive OS is 14.7.6. While I may be one or two OS releases behind, I always update my current OS when they become available. I can only assume the Recovery Mode OS is the same.

No you cannot assume anything. While booted into Recovery Mode, what OS is available to reinstall? That is the OS installer you are accessing in Recovery Mode.

I don't recall if I've ever run First Aid on the physical SSD (APPLE SSD AP0512Z Media). Because I follow Apple's instructions to open the device tree and run First Aid on each device from the bottom-up, after beach-balling on the Container, I don't get to the physical SSD.

It is actually better to run it on the physical drive first since it can confirm the partition table is Ok. Then run it on the hidden APFS Container which will automatically run First Aid on the container & each APFS volume within that container. Apple just hides everything from users these days which is why Apple's instructions are different and in my opinion just plain wrong. It the base is not correct, how can the upper floors be Ok (base is physical drive & container, upper floors APFS volumes)?

Here's something that may be a factor: I have run First Aid on my Time Machine drive (also an SSD), but NOT while in Recovery Mode. Could that have caused any snapshot issues?

No. APFS TM backup snapshots on your boot drive are just APFS snapshots formed from locking the file system into the state it was at snapshot creation. The main APFS volume which was the source of the snapshot continues to change as you use it.

When TM backs up to external media, TM will use those frozen snapshot images to create the backup on the external media. The file system on the boot drive and the TM backup drive are completely independent of one another.

My concern regarding the version of macOS on the boot drive and the one being accessed in recovery mode is that the version of Disk Utility in recovery mode is the same or newer. Who knows what happens when an old version of Disk Utility is used to scan a newer file system.

Mike Harrison wrote:

But, just because I'm the curious type, when I run First Aid on the Data volume, and it reports the missing resource fork issue with each of the snapshot files... and then claims to repair them, if I run First Aid again, the same issues are there again. Very puzzling.

Disk Utility is a terrible app, but it is all we have for APFS file systems.

Just ignore the errors on the snapshots since they will go away once those snapshots are deleted.

Mike Harrison wrote:

Thanks. I wish they WOULD go away. This has been going on for quite some time. Is there a way for me to delete them?

Here is an Apple article with instructions:

View APFS snapshots in Disk Utility on Mac - Apple Support