WARN SNAPSHOT_CHECK Chunk has a size of 0

Support
#1

I’m getting a lot of “WARN SNAPSHOT_CHECK Chunk has a size of 0” errors when running a check on a local datastore. I deleted the datastore and recreated, the same issue comes up after running a backup and running a job to check the datastore. It seems to only happen if the datastore has erasure coding configured. My other datastore without it doesn’t have the same issue.

Here is the log from the check job

#2

Erasure coding is done before the chunk is uploaded so I’m not sure how it could lead to this.

Can you run a small backup (like 10 GB) to see if you can reproduce the issue?

#3

Sure thing!
I created two new Storage locations, one with erasure and one without. Then I added in a folder that is roughly 10GB, ran the backup, then ran the check task and got the same results.
Schedule: https://i.imgur.com/PimdSA9.png
Log from Failure: https://i.imgur.com/pdg0iP6.png
Log from success: https://i.imgur.com/dYRbt4R.png

#4

Which CLI version are you running?

#5

duplicacy_web_linux_x64_1.7.2 on Linux Mint 21.2

#6

This is web ui version. You can check in the beginning of any of the backup or check or prune log files what was the version of a CLI engine that did the job.
It’s also configurable in the WebUI settings. That the version gchen was asking for.

#7

Ah gotcha thank you, the CLI version is 3.1.0

#8

You can use the strace tool check if it is Duplicacy that creates empty files.

In a terminal, run these commands:

cd ~/.duplicacy-web/repositories/localhost/n #(where n is the index of the backup)
strace -f -o /tmp/output ~/.duplicacy-web/bin/duplicacy_linux_x64_3.1.0 backup

If you see an empty chunk after the backup command, you can go back to the /tmp/output file where you find the function calls related to that chunk (search by the chunk name) and check if the write call returned 0.

#9

Hmm. The repositories/localhost dir is empty.

backupuser@duplicacy01:~/.duplicacy-web/repositories/localhost$ ls -a
.  ..
backupuser@duplicacy01:~/.duplicacy-web/repositories/localhost$

Edit: Nevermind, i found it at this location.
/root/.duplicacy-web/repositories

Will report back when i’ve ran the other command