Michael Büker

A way to efficiently test this issue might be to manipulate the date/time of a VM to simulate the passing of weeks and months quickly.

I have created a testbed with the following shell code in a VM: ```for N in {1..60}; do sudo date -s '+7 days'; echo date > backupfile; backintime backup; done```...

I think I'm very close to cracking this case. In this function: https://github.com/bit-team/backintime/blob/22f468c32732be6c821686e0c504b4dfb920487a/common/snapshots.py#L1686-L1696 … `smartRemoveKeepFirst` is called with a `max_date` of `d + datetime.timedelta(days=8)` — not `days=7`! Therefore, in a...

> There are some unit tests in `test_snapshot.py` about that smart remove thing. I touched some once long ago but then gave up. A full refactoring of that tests would...

> It occurred to me that what makes the "smart remove" behavior confusing is that the snapshots are named using only the timestamp. The names don't contain "hourly", "daily", "weekly",...

> I know that. To figure out the [workaround](https://github.com/bit-team/backintime/issues/1094#issuecomment-636493410) I posted above, I added logging code in the smart-remove processing to log the "kept" and "removed" snapshots, so I could...

It's a difficult problem, but a relevant edge case: What if you take a backup of a mounted filesystem with UIDs and GIDs different from those on your local system?...

I'm editing the title and adding this comment to make the feature request more clear. I still think it would be a nice feature. OP wants to select **any two...

> We have a compare snapshots dialog for this. It is kind of hidden but the feature exists. > > https://backintime.readthedocs.io/en/latest/snapshotsdialog.html Hmm. I thought this only applies to single files,...

> On a long run my idea is to remove that snapshot dialog and integrate all its features into the main window. As you described, select two snapshots in the...