Fedora 31 workstation, Duplicati - 2.0.4.34_canary_2019-11-05
When nearing the end of the backup, the file size remaining to be backed up becomes a negative number. I am attempting to upload a screenshot here.
When the backup first starts, Duplicati scans the filesystem to find files that should be backed up and it also notes the total size of all those files.
If some files grow larger after they are scanned at the start of the backup - but before Duplicati has backed them up - then it can throw off this ābytes to goā calculation.
It is superficial and can be ignored. The UI should probably be adjusted to hide the āxx bytesā portion if it goes negative.
A fix was made a few months ago for another situation where this number could be negative: files were temporarily counted twice against the total bytes processed. But your version has that fix so this is a different issue - probably file growth during backup.
Just adding that I think I ran into the same bug. While the backup was occurring, I added some zip files. I then ended up with this and the backup got āstuckā. I had to restart the Duplicati service entirely.
It happens all the time, every backup that runs. If thereās some log info you want, let me know and Iāll try to provide it.
Iām running 2.0.6.100_canary_2021-08-11 on a debian linux distro.
How long does your backup job run? As I mentioned above, one cause of this issue is when the files change between the time the job starts and the time Duplicati actually gets around to backing up those files. But your numbers are really large. Seems quite odd especially if your backups complete in a short timeframe.
The negative values show up immediately when the job starts, so doubtful it has to do with a file changing between the scan and the actual backup. Also not sure what you consider a āshort timeframeā. Most of the jobs I have are examining and backing up 10s if not 100s of GB, depending on activity. The shortest backups I have take a few minutes, the longest nearly an hour.
To my programmer nose, this smells like bad signed int ā long, long ā int conversion.
Can you give me more detail on your Debian system? What version of mono are you using, and what filesystem format are you using (ext4, etc)? (They are local files, right?)
Try this⦠open two tabs to the Duplicati Web UI. On the first tab navigate to About ā Show Log ā Live ā and set the dropdown to Verbose. On the second tab, start your backup job. Quickly go back to the first tab and watch for any errors while the filesystem is enumerated.
Yeah we donāt need a full log⦠I was just hoping some sort of problem would be visible that you could screen capture. Maybe try the test with Live Log set to āWarningā, it should help reduce the output.
Ran a test backup with a single 10G file. The UI showed negative values for the progress and definitely nothing obviously useful being logged. Just mundane stuff about whatās itās doing.
Ok, I like your idea of testing with a small amount of data. I think you might need to use the various log-file options to save logs to a file. Try setting the log level to Verbose and run your test again.
Thatās actually what I did. Had logging set to verbose. The logging was basically telling me what was happening, but nothing would indicate why it was showing negative values.
Which progress? I can see how a math error might make size negative. Was files negative too?
If you suspect an integer overflow problem, maybe trying a file size of about 2 GB might be helpful.
You can see the progress in a more raw form on About ā System info. Ctrl-A and Ctrl-C the page.
Pasting that into notepad for a look let me test how the status bar values were derived. Status bar:
For files, remaining is 787 - 225 = 562. For size, remaining is 569002300 - 25079669 = 543922631.
Thatās 518.73 MiB (I guess the status bar MB is really MiB). From message search, I think the code is
I donāt really do JavaScript or C#, but I think @drwtsn32 has looked at the C# end of computing these.
The web UI gets it from the server, so itās also possible to capture packets or maybe use browser tools.
Edge F12 Developer Tools caught a series of progressstate. An example of what the server returned: