[prmoustache]

>I see your point, but from the perspective of the Android phone, this is already a backup. This is because if I lose the phone, I can restore the important parts of its state from the copy on the server - which is the definition of a backup, according to Wikipedia for example.

I am not familiar enough with nextcloud but what happens if - excluding your home server setup - you modify a picture on your smartphone and overwrite it? I guess it is synchronized to the nextcloud server in modified form and replace the original file, right[1]? If so what if you were to realize you screwed up and should not have overwritten it? Hence the reason I am saying it is not exactly a backup.

[1] that would be the behavior I expect of a syncing mechanism, I use syncthing-fork myself for that.

[npteljes]

Ah, right, then maybe I didn't see the point after all. Nextcloud handles this quite well though, I think, it will say, on the phone, that there is a conflict between the two versions of the file, and in case of images, it ever shows them side by side, and asks you what to do.

[prmoustache]

OK in that case that makes at least clearer for the user. Thanks.

[MrDrMcCoy]

Nextcloud has a first-party plugin that keeps a version history, which is very useful to enable to mitigate issues like this. That combined with the default behavior that deletions on devices only go to the trash on the server turns it into a real backup option.

[prmoustache]

Oh that's great. Thanks.