Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Time Machine snapshot could not be created for the disk "%@"

I just upgraded my iMac (Retina 5K, 27-inch, Late 2014) to Big Sur. All went well, except Time Machine now will no longer create a backup.


I get the error: "Time Machine could not back up the disk "%@" because a snapshot of the disk could not be created."



I have about 87GB free on my single 1TB Fusion Drive.


After some googling, I have tried:

a. Run Disk Utility First Aid on the Fusion Drive (and again on the contained volumes - no issues).

b. Deleted old local snapshots - to free up space (tmutil listlocalsnapshots / etc.).

c. Confirmed I could manually create a new snapshot (tmutil snapshot).

d. Tried using a new Time Machine backup disk (no difference, as I assume the issue is happening before it actually backs up to the backup disk itself).


I suspect the key to the problem is the disk "%@" that Time Machine is apparnetly trying to create a snapshot of.


What is disk "%@" ? It sounds like a bogus disk reference? (which might explain why a snapshot could not be created).


I'm not sure what to try next?

Posted on Nov 17, 2020 12:12 PM

Reply
48 replies

Nov 30, 2020 2:26 AM in response to Natedogg33

If you're using Western Digital or SanDisk drives, download and install the latest WD Discovery suite. Reboot (this is essential) and then connect each drive. Make sure UAS is OFF for each (gear icon next to the drive). Eject, and reconnect. Problem should be solved. It solved it for my WD SSD Passport external drives. Flying once again, no beach-balls, no crashing with scary data loss messages. You might need to reformat a Time Machine to get it to be stable in backing up (APFS format with GUID partitions, encrypted too if you want to keep it secure). Hope this helps!

Nov 30, 2020 9:03 AM in response to Darren Hatch

@Darren Hatch. As noted earlier, the reported error is during the creation of the disk snapshot of your internal drive, *on* your internal drive. ie. Before backup data is written to your external Time Machine backup drive. Changing your Time Machine backup disk and/or reformatting it, is not where the problem lies. The problem is with the creation of a snapshot of, and on, your internal Mac OS drive.

An apparent solution to the snapshot permissions (that appear to be the root cause) has been posted above. I'm just not able to verify the posted solution for myself, as I'd already resolved my issue via the clean install procedure (that I also posted earlier).

Jan 4, 2021 2:44 PM in response to mbmitt

@mbmitt So are you seriosusly saying that even the solution I took (posted earlier) of a complete clean Big Sur installation didn't even work for you? If so, did you follow the procedure I outlined to ensure a full disk erase, clean install, and then data recovery.


If you instead only tried the other solutions posted (without any success), then please post what your steps were, so that someone can assist you with where it might have gone wrong. Hopefully someone can get this issue resolved for you also.

Jan 4, 2021 3:14 PM in response to mbmitt

The terminal commands I posted above to remove the old TM backups from prior versions of the OS should have done the trick. If not, then the complete disk erase and clean install described by @KoolKiwi *will* definitely fix the problem (though it's quite a bit more work to do).


Did you get any error messages when you tried the solutions posted above?

Jan 4, 2021 3:26 PM in response to KimballLarsen

Yes, just to reiterate, I did the complete clean Big Sur install prior to @KimballLarsen's quick Terminal commands solution. So, unless there is an absolute need to, I'd just focus on the terminal commands solution. :)


However, for me at least, I'm happy I proceeded with the clean re-install approach as I also obtained the benefit of a significant performance boost (which I'd account for having never done a clean install previously, after many years and many OS release upgrades). Of course, YMMV!

Time Machine snapshot could not be created for the disk "%@"

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.