Deja Dup Issue

[TheFu]

Just another strange thing about this. I calculated exactly the size of the backup, which is 287.4 GB. And the error message is "Backup location does not have enough free space. Try using a location with at least 574.8 GB.
Exactly double the backup size. I'm stumped.

Out of inodes, perhaps? This is unlikely on a disk that size with ext4 as the file system, but stranger things have happened.
df -i and df -Th are your friends here.

[donald187]

This was a first full Backup.

I assumed so. As I'm sure you know Deja Dup (Duplicity) can't just make incremental backups for forever. It has to do a second full backup at some point. But it won't have enough space. I'm just suggesting that Deja Dup knows this and is preemptively saying that there's not (won't be) enough room. But who knows. It might be interesting to see if it will back up something with size less than half the size of your backup disk (less several GB to be safe).

[donald187]

Does anyone know where Deja Dup keeps its config files? I'll try deleting everything and start with a clean config.

Duplicity keeps some files in .cache in the duplicity folder. Namely the manifest and signature files. When I want to start over in Duplicity I delete the appropriate sub-folder. Deja Dup also has settings--I have used the dconf-editor to reset settings back to their defaults. I don't know if there are other default settings somewhere. Under org.gnome.deja-dup I believe. Not sure about punctuation there.

[dragonfly41]

In synaptic I installed
dconf-cli
dconf-editor
Opening dconf-editor (with warnings) shows deja-dup settings.

[speartip]

I assumed so. As I'm sure you know Deja Dup (Duplicity) can't just make incremental backups for forever. It has to do a second full backup at some point. But it won't have enough space. I'm just suggesting that Deja Dup knows this and is preemptively saying that there's not (won't be) enough room. But who knows. It might be interesting to see if it will back up something with size less than half the size of your backup disk (less several GB to be safe).

After Googling around, apparerently this is the issue. In all the years I've used Deja Dup I've not come across this before, but apparently it does indeed need double the size of the backup otherwise it will stall.
That's space that I do not have. I never appeared to have this issue in 22.04, so it must be something new in the 24.04 version of DejaDup.
For now I'm trying rdiff-backup instead.