Temporary files remain at tempdir

after a successful backup of 250GByte to a local drive, about 350GB of files remain in duplicatis tempdrive.
Shouldn’t duplicati delete them automatically? May I delete them or shouldn’t I?

You are talking about the dup-* files? I think you had some interrupted backups when you were doing your testing… that may be why you had some left like that. Normally you shouldn’t see them. Duplicati will eventually delete them automatically, but it waits 30 days (far too long in my opinion).

You can delete them manually. Make sure there are no active tasks/jobs running of course.

What version of Duplicati is this? There have been at least three fixes which went Beta in
Main one might be the below, but it probably only avoids new problems (won’t clean up old ones).


Fixed a case where temporary files were not removed, thanks @warwickmm

Remove temporary files from backup and compact operations #3662

You could look at the file dates and job logs from then to see what might have left things behind…

I was helping OP in another thread and he says he is using But there were interrupted backups, so that may have been why temp files remain.

In the Duplicati source I can see that it will eventually clean up the temp files but it waits 30 days (seems way too long IMO):

The quantity of temp files (350 GB) exceeds what I guess is the source size (250 GB), so neither the compact issue that’s fixed nor the interrupted backup idea fit if it showed up at once, but it’s unknown. What I’d like to think is that these are old files, and isn’t making these as much as old version.

Regarding 30 days, any impact from that length is reduced if has fewer leftovers than before. There might be some rare situations when a temporary file finishes its writes then sits for a long time. Maybe one case is while waiting for multiple block creating process to end, and spills to be collected.

There are certainly long operations possible. Are any temp files in write-then-read-much-later mode?
I’ve never studied temp files closely, but they’re used for a large variety of different things in Duplicati. Sometimes even figuring out what they are (without code study) requires opening them up to inspect.


Or maybe they were new, although the numbers don’t match. The other post was a backup of 1.5TB, using remote volume size of 2TB due to not understanding what that meant, despite UI note and link.


at least I stopped duplicati an deleted the files. They seem to have remained after form my first attempts with duplicati.