Restore speed slow (not network related)



First time user here. I am backing up a ~5TB set of Data to B2 backend. Encryption is enabled. Upload volume size is set to 500MB. Initial backup is still in progress but due to connection interruption today (12hrs) backup stopped therefore I wanted to try restoring a file.

After 20 minutes it is still “verifying remote data” but I barely see any traffic from duplicati host + cpu is idling at 14%.

What is duplicati doing when doing “verifying remote data”? The file to be restored is 300MB, i.e. I would expect it to be spread to 2 archives max. Content has not changed.


after posting I had the brilliant idea of checking live logs from server and I get error

  • Nov 6, 2018 10:57 PM: Backend event: List - Retrying: ()
  • Nov 6, 2018 10:57 PM: Operation List with file attempt 2 of 5 failed with message: Error: ConnectFailure (Connection timed out)
  • Nov 6, 2018 10:49 PM: Backend event: List - Started: ()

I don’t understand why this is happening, connectivity is good. Where do I see which URL Duplicati is trying to open while verifying remote data?


The B2 URL varies and I don’t think you can directly get Duplicati to show it (short of using a debugger), but Calling the API expresses the idea. The 123 stands for a three digit number showing where B2 has sent you. This sort of go-there behavior is even more prevalent on uploads, where you might get redirected anytime… This is all supposed to be handled automatically, but seemingly you’re having some sort of connecting issue, which you could try to check in “netstat”, Wireshark, or something like that. Don’t expect IP name resolutions. Easy non-connect would be SYN_SENT, saying TCP-level connect didn’t occur. Beyond that, it gets complex.


I see the following output of netstat

Foreign Address (state) SYN_SENT

which suggests that B2 doesn’t acknowledge connection attempt.

but since in the meantime another error appeared in log file:

Nov 6, 2018 11:28 PM: UsageReporter failed
(connection timeout as well)

I decided to restart duplicati and voilà connections work again.


How did you determine that the file you wanted to test restore had already been backed up?


I’m glad it’s working, but I don’t know why. Duplicati doesn’t run the low-level TCP protocol. That’s up to the OS.