So, you would pick daily and use the same command that cron does: /var/lib/openmediavault/cron.d/rsnapshot daily The only issue I can think of that could possibly happen is that the rsnapshot daily command would execute twice if your server was on at 3:30 am.
well it is actually not that easy to read what is the exact command the cronjob does because it is quite some code in that file. Actually in cron.d is only a file named rsnapshot with a bit of code in it. I am unsure which would be the command i would need to copy.
secondly: Well lets see maybe it is possible to not activate rsnapshot over the addon-webinteraface at all or put it to 0 or sth like that, sothat it wouldnt backup twice a day.
I actually wonder that this question is not yet completely solved somewhere since it should be sth alot of people with WOL-Servers should be looking for. Also I dont understand why the plugin does not offer anacron. It would be extremly handy.
So I guess figuring that out here would help some people too.
Thanks alot in advance!