How to safely delete old Time Machine snapshots from a sparsebundle?

I can't answer your first question but Time Machine (TM) backups are on a strongly protected volume. You either have to do things through TM itself (if it will let you) or you have to erase the entire TM volume. From your image, it appears that you could delete those files.

I don't know that there would be much point in doing so. TM is supposed to be self-managing when it comes to space and should delete older items if it needs space to do a backup of newer ones.

vitalii_with_apple wrote:

I have TimeMachine backups stored in a sparsebundle on my NAS. When I connect to the NAS via SMB and mount the sparsebundle by opening it in Finder, it shows me many snapshots (see the screenshot).

https://discussions.apple.com/content/attachment/f99fdc13-14ac-46d8-92e4-e19323314362

Can I safely delete old snapshots from it to make the entire sparsebundle less in size? I will help with speed of downloading the entire sparsebundle when restoring remotely. I only need the latest snapshot.

If so, how? Is it save to delete them using Finder? Or the Terminal?

In older versions of the MacOS, one used to be able to delete some of these backup sets from within Time Machine. However I believe this is no longer an option and manually deleting any of them risks making the backups for this device unusable.

To explain why this is the case would take more space than is possible here, but briefly: Time Machine does not store separate, complete backups for each date/time. If your Mac and it was using 1 TB, then ten such backups would take 10 TB! Typically only a factor of 2x-3x space is required. Time Machine only writes new files when the file has changed, otherwise it "keeps" the older already backed up version in the new backup set via special links. One can open those backups manually in the Finder and copy individual files back but physically the file is being copied from a different place. Hence deleting backup sets directly will break those special links and some or none of the backups will be functional.

For instance, restoring your Mac completely to its state on a specific date in the past may require physically copying files from many different backup sets. Those special links make this transparent to the user. But manually deleting some of those backup sets breaks this and it will no longer function.

I'm not sure I can suggest a good solution for you. For those of us using individual directly connected Time Machine backup drives, typically drives do not fill up because older backups are removed to make room for newer ones automatically. The removal of older backups, by the way, is very time consuming for Time Machine due to that labyrinth of nested links, hence you may see Time Machine "cleaning up" or "preparing" for long periods of time. There is no longer a way for users to do this manually. Perhaps, if you really only need the latest backup, maybe Time Machine is not the best approach for you because its strength is in the versioned backups it provides. You might look into various "cloning" solutions (CCC, SuperDuper ...), I believe both work with NAS.

vitalii_with_apple wrote:

steve626, thank you for the very detailed answer. Very useful. Maybe one day I'll verify a restoration from TM .sparsebundle after deleting one of its snapshots.

Good luck with this going forward! Note, however, that even if you do this "experiment" and it appears to be successful, that might be because the snapshot you deleted happened to not contain any linked files for the backup you restored from. In a future instance, that might not be the case and if such linked items are deleted, the restoration 100% will not work.

Just a warning: you may find yourself in a position if you try to delete an item from the Time Machine drive of not being able to empty the Trash bin or putting the file back where it came from on the TM drive. The only way out of that situation is to erase and reformat the TM drive.

That situation is not so disastrous if there are no files on the TM backups that you don't have on your active drives or you don't need them.

Just some food for thought.

No, you should not delete those snapshots manually, and the reason isn’t philosophical, it’s structural. What you’re seeing inside the sparsebundle aren’t independent backups, they’re a web of hard links that Time Machine relies on to reconstruct any given point in time.

Even if you think you only care about the latest snapshot, that snapshot almost certainly references data physically stored in older ones. Deleting a snapshot in Finder or via Terminal won’t reliably shrink the sparsebundle in a meaningful way, but it can silently break restores later, especially full-system or Migration Assistant restores, which need that link graph intact. macOS doesn’t provide any supported way to prune network-based Time Machine backups down to a single snapshot; it’s all or nothing.

If your real goal is faster remote recovery, the practical fix is to stop using Time Machine for that use case and keep a separate single-state backup, like a periodic APFS clone or archive created locally and synced to the NAS. Time Machine is designed for versioned history, not for efficient single-image restores over SMB, and fighting that design usually ends with a corrupted backup when you actually need it.

Can I safely delete old snapshots from it to make the entire sparsebundle less in size?

Assuming "safely" implies without corrupting the entire backup, the answer to that question is no.