Cronjob - configuring day 1-7 impossible in combination with specific day?

[n8c]

Howdy,

I wanted to configure my HDD scrub to only run on the 1st Sunday of the month. Whatever day that actually lands on. And only once per month. Sounds easy enough

I thought I had done that, but in reality… and it gets very weird imo.

• I cannot configure days to be 0-7, that is invalid (0 is invalid. which makes sense)
• Configuring (only) 1 is wrong, because I want the first Sunday, not the first day of the month.
• Configuring Sunday is wrong, because I only want it to run once per month.
• Configuring 1-7 is correct in that the NAS is physically powered off the rest of the week at the cronjob times (this is what I had configured).
• But 1-7 results into “BETWEEN" 1-7”, which is not helpful as well. The first run is emitted to be on the 2nd. Which is not a Sunday.
• Configuring 1,1-7 actually emits that it would do it like I want, the words change to “one THROUGH seven” as well.
  • Why tf though is the 7 now suddenly “THROUGH” when it was “BETWEEN” before? With the same logic, it should now do 1+(2-6) requiring me to input 1,1-7,7. Otherwise it treat 1-7 differently depending on if there’s other days mentioned around it (which would be very wtf).

=> this behaviour seems weird to me.

Is there an actual issue: Well yes. The NAS will see the light of day on Sundays. The logic becomes an OR once I play with the day-selector. So 1-7 has to be the thing.

But today, with a config of 1-7, the thing didn’t do anything. No log, nothing. It says it will run the next time tomorrow - which is completely wrong of course.

The “next run” preview states it would run on the 1st though (see below for March). But then why didn’t it run today. That makes me believe the wording “between” more than the preview.

Ideas? Am I doing something wrong?? Is this normal? Is this a cronjob limitation of linux in general? Very weird UX in any case (which doesn’t have to be TrueNAS’s fault).

The timezone is properly set over the whole system - I stumbled upon that a few weeks ago already when setting everything up. Shows the current time just as my PC does. The NAS was powered on ~1h before the job should have started, so no “too close to runtime” issue as well.

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Alternative idea: If it is what it is https://stackoverflow.com/questions/34357126/why-crontab-uses-or-when-both-day-of-month-and-day-of-week-specified

then a solution might be that I hereby feature request seemingly existing alternatives? https://stackoverflow.com/questions/3241086/how-to-schedule-to-run-first-sunday-of-every-month

Because maybe at some point my NAS will run 24/7 and then the “first Sunday of the month” thing goes boom anyway (with the current options in the UI), no?

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Otherwise: Thanks for a great and properly working software with much functionality ready to use. Perfect merger of ez and techyness!

Cheers

[dan]

@n8c

Is this a cronjob limitation of linux in general?

Yes. There’s no way in cron syntax directly to do what you’re asking, and the TrueNAS UI tracks what cron can do. So what to do?

• Set your cron job to run every Sunday, and include a conditional in your command to ensure that the day of the month is 1-7 (i.e., the first week of the month).
  • e.g., for your “Command,” enter [ "$(date +\%d)" -le 7 ] && /path/to/whatever
• Set your cron job to run days 1-7 of the month, and include a conditional to test if the day of the week is Sunday
• Particularly if what you want to run is a script anyway, set the cron job to run every Sunday, or days 1-7 of the month, and include the conditional in the script.

[n8c]

Phew…

Thanks, and oh noes

Guess I’ll tinker with the stack’s idea

(2nd one so https://stackoverflow.com/a/51343686 )

and adjust the system-created cron.

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No idea why tf even the system-created one doesn’t run when adjusting to only stars (no date check yet mind you), yet the manual button works… running the cron command manually doesn’t work as well.

Did something change with the commands/shouldn’t that work? (I am elevated to root of course)

PATH="/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/root/bin" midclt call pool.scrub.run HDD-01-04TB 35 > /dev/null 2> /dev/null

This would be the CMD from /etc/cron.d/middlewared (system created mind you! Wiped and recreated it via UI and is 1:1 to the SSD one anyway).

[winnielinnie]

@n8c

• Configuring (only) 1 is wrong, because I want the first Sunday, not the first day of the month.
• Configuring Sunday is wrong, because I only want it to run once per month.

Isn’t this already built into the UI for scheduling scrubs?

Configure a pool’s scrub to run weekly on Sundays. Choose a threshold value of 35 days.

Every Sunday, It will check if it’s been at least 35 days since the last scrub. If not, it skips scrubbing on that Sunday.

If you want it to line up with the first Sunday of the month, then you need to manually run a scrub on the first Sunday of a month before you enable the scrub task schedule.