TIme of execution of daily anacron job

Question

I have set a daily anacron job, which runs form /etc/cron.daily. From the /etc/crontab I see it should run daily at 06:25 (or at start-up/reboot).

However when the date changes (00:00) and the computer is up, I dont want anacron to wait till 06:25. If the computer is up I would like to it to run the script as soon as the date changes (00:00). Does it make sense to add a cron job to run anacron @hourly?

Thank you very much

Answer 1

You can just change the line:

25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )

to read

0 0    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )

This will make the execution of daily cron jobs start at midnight.

Answer 2

I found how to do this and summarized it in my blogpost:

• http://opensourceresearchtips.blogspot.com/2012/01/linux-anacron-tips.html

If you want to change the behaviour of anacron to execute as soon as the day changes (and not wait till 7:30 as is the default behaviour) do the following:

gksu gedit /etc/cron.d/anacron

and add the last 2 lines (the last line will restart anacron every hour):

01 0    * * *   root test -x /etc/init.d/anacron && /usr/sbin/invoke-rc.d anacron start >/dev/null
01 0    * * *   root start -q anacron || :
@hourly root start -q anacron |

| :

Answer 3

The answer by Khaled is not correct. Changing this line will not have an effect if anacron is installed (which it is, by default):

25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )

If anacron exists, "test -x /usr/sbin/anacron" will return true, and prevent the second half of that line from running. The other answer (editing /etc.cron.d/anacron) is correct, since that's the config that will kick off anacron itself.