Diffs between snapshots, snapshot unique size

So these are two loosely related questions about snapshot information, it is something that I’m always curious about with backup programs and filesystems able to snapshot.

One, I’d like to diff two snapshots (normally two consecutive ones, but no matter). I know I can mount and use any diffing program, but I am looking for something in-kopia that could be faster e.g. for remote backends. Going through the help didn’t turn anything evident.

The second one is whether there is a way to know the “unique” size of a snapshot, and by that I mean which files are present only in that snapshot. That is, if you were to delete it, what space would you recover/files would be lost forever. I don’t really see a way of doing this externally.

Thanks for any hints.

Have you tried kopia diff ? It does not report size difference (contributions to add this are welcome), but would generally tell you the difference between two snapshots.

Oh man, I totally missed it in the help output. I’ve just tried it with two root snapshot ids and got this:

$ kopia diff k365a3a1d6641c3bd89092c85ea8ef044 k60e4e5686533fcc2aef7c0d42f75c7d5
ERROR comparing files not implemented yet

This is with v0.9.7.

kopia diff works fine for me with v0.9.7

It also works for me in another computer… Curious.

I think I found the reason. The diff returning the error is for remote snapshots taken in other machine. So my setup is that I have a common backend (rclone to gdrive), and snapshots in the local machine work fine with diff but snapshots taken in other machines cannot be diff’d locally.