Backup process stucks on random file

Support
1

Version: Duplicati - 2.0.5.111_canary_2020-09-26 (some preciouses versions had the same malfunction).
Scheduled backup starts and stuck in a middle of process while backing up files. Sometime it’s the same file, sometime it’s another.
If I press Stop on current file, the process stuck on Stopping – “Stopping after the current file:…”
If Stop Windows Service (“Duplicati service”), the process “Duplicati.Server.exe” still running with changing thread amount – 19-20-19-20-19-20-19-20 or 31-32-31-32-31-32-31-32 in my last case.
Nothing can stop the process except Task manager Terminate process.
When I terminate the process, start Windows service and start the backup Job, Duplicati stuck at the same file or close to it.
The job backing up to webdav, operation timeout is 2 minutes. Yesterday I have spent more than 2 hours looking at progress bar stuck on a small file.
If I disconnect from internet and connect back the process do not timed out our show any error.
I didn’t have successful backup for a week :frowning:
The last command in remote log is
: put duplicati-b930f5532c34d461a9d4165fd01448c37.dblock.zip.aes
{“Size”:104829453,“Hash”:“xRJHsE3kVCDMZKKVrDVg+SQgFZTMrVdcShfa01TFLVM=”}
Timestamp is 40 minutes ago.

In general log I can see previous job only, because of Task manager kill, I think.
One more try. Truck on the same file.

Job: 18177 files (28.75 GB) to go at 7.77 KB/s
Nothing is changed but speed (going down)
Job: 18177 files (28.75 GB) to go at 2.90 KB/s

I’m trying make a bug report via Job’s command:
Reporting:
Show log … Create bug report …
I’m clicking and nothing happens (job still in progress).

What a magic file which breaks the program!

2

Setting “snapshot-policy” = “required” allowed me to complete the backup procedure, finally!

3

helped not much, the job just stucks on another file.

4

Seemingly declining speed is sometimes due to problems getting files uploaded. How are those going?

Please see job log’s Complete log → BackendStatistics → RetryAttempts for a job that finished.

About → Show log → Live → Retry shows retries, or set a log-file=<path> with log-file-log-level=retry

This is another sign that there could be something on the network side that’s causing backup flow to stop.
asynchronous-upload-limit will only queue so many files before it considers file queue too big to add more.
If you have lots of Temp space, I guess you could set this limit much larger to see if the stuck spot moves.

Another sign is if you get a number of files (default size 50 MB) in your Temp folder waiting to be uploaded.
For some reason the dir /od dup-* command in Command Prompt shows ones in progress as empty.
You could try looking in %TEMP% anyway, or maybe Explorer can give you an accurate view of files there.
PowerShell stays current, and you could run ls $env:TEMP\dup-* | sort -Property LastWriteTime

Yet another sign that it’s not a specific file. Was the last file consistent across runs originally? It’s not now.

Do you have any other destinations available to test to see if this seems a source problem or destination?