Scheduled rsync job only works manually

Hello!

I have scheduled an rsync backup of a webserver via the "Scheduled Jobs" tab like this:

sudo rsync -caAXz --exclude={"/home/someuser/","thumbnails/","cache/","Cache/","tmp/"} backupuser@domain.net:/{opt,etc,home,var} /media/.../backup/ 2>/media/.../rsynclog.txt

This command works as suspected via terminal, but as a scheduled task I get the following error:
rsync: link_stat "/{opt,etc,home,var}" failed: No such file or directory

Strangely, the task works when started manually with the 'Run'-button, but fails each time when scheduled

Any suggestions?

Thank you very much for your prompt answer!

When I understand you correctly it is not possible to use rsync via ssh with PSA through the rsync webgui. I have tried that and can confirm that it does not work

This is why I set it up under System>Scheduled Jobs. There it works correctly if I trigger the job manually (by clicking 'Run'), but at scheduled times I only get the error message above. Do you have an idea why this could be?

I got the error in the log. I tried removing the log redirect pipe now and got the same error through email notification. I also tried changing the user to 'root', that gave me the same error aswell.

PKA is allowed, the keys are stored in /root/.ssh and ~/.ssh for the backup user. I know that the connection is configured porperly because the backup works fine when I use the command as the same user via CLI or trigger the job manually in the Scheduled Jobs tab - if there were a fault, that shouldn't work aswell, or am I mistaken?

I just can't get my head aroud what could go wrong when the job gets triggered automatically.

I think I figured it out. Will test and report.

TIl that crontab does not like complex commands/special characters. Running a scheduled job manually is not done via crontab, that's why it works then.

Solution: Wrapped the command it in a shell script and called that with the scheduled jobs webgui. Works like a charm.

Thank you for your answers, subzero79!

I don't think Openmediavault did anything wrong here. Adding the command to the users crontab via crontab -e gave the same error. This suggests that crontab uses sh shell instead of bash which does not support {} brackets.

Could I just call multiple directories with ( ) or [ ] then? Or would I likely run into other problems? I have no experience whatsoever with sh.

Thank you for clarifying. It seems like sticking to the shell script is the better option, then. I currently have no write access to the server, so I can't create symlinks. It is a neat idea though, maybe I will use it in another scenario.