Let me preface this by saying that I really know nothing about Duplicity. The person in my organisation that has the knowledge has gone on leave and as usual, while he's away, unusual things happen.
I got an alert today that one of our servers had suddenly filled up the root volume. This server has been running for years and the root volume is (was) only 5GB as it never really had anything in it, and we've never had an issue with the volume even coming close to filling. I tracked down the usage being attributed to the /root/.cache/duplicity folder. The server was running it's monthly cronjob at the time that does a 'remove-older-than 1Y' followed by a 'remove-all-inc-of-but-n-full 3'. It was during the remove-older-than operation that the disk filled up. Looks like part way through last month we had a significant increase in changes of data on that server which has caused the incremental backups to suddenly increase in size. Of course, this is speculation as I really don't know what I'm looking at (as I've already mentioned).
So, I just increased the size of the root partition to 20GB on the fly (thank you LVM) but it seemed the job had kinda hung. I killed the child process that was doing the remove-older-than task and the parent script then went on and processed the second task. When this ended, I got the backup reports for the two tasks which showed the python traceback with the error of "No space left on device" - not unexpected.
This has left me with a few questions:
If I'm understanding this correctly, and from what I saw on the server, it appears both of these tasks downloads a bunch of backup files from the remote storage location (via ssh) to the local /root/.cache/duplicity folder for some reason and then presumably cleans these up at the end. Is that correct? If so, I'm not fully understanding what files need to be downloaded and the exact purpose of this.
This has left me four "duplicity-full-signatures" files and their associated manifest files, one each for Sept/Oct and two for Nov, as well as a few "duplicity-new-signatures" files and associated "duplicity-inc" manifest files that seems to cover the previous month (however, it looks like the first file might be missing - I'm assuming that was what was being downloaded when the disk filled up). I compared these with one of our other servers that uses Duplicity and runs the same cronjob at the same time, and this other server only has a full-signature files (one each for Sept/Oct/Nov) and the associated manifest file. No inc manifests or new-signatures files at all. I'm wondering what might be the correct way to go about cleaning these up, or even if I need to at all. Either I'd just manually delete the full-signature & inc files so it has the same type of files as the server without issues, I just leave them there until next run and they may or may not get cleaned up, or I run the monthly cronjob manually again and let it overwrite the files and clean them up properly at the end.
Forgive the newbie questions, this is my first experience with Duplicity.
