DSM-G600, DNS-3xx and NSA-220 Hack Forum

ismora wrote:

Maybe you can try to add in /var/spool/cron/crontabs/root :
*/5 * * * *       su - -c "/path/to/the/command"

That would run the command as root.

An alternative would be:
*/5 * * * *       su - nobody -c "/path/to/the/command"

Or even better:
1. su to root
2. crontab -u nobody
3. Add the following line
*/5 * * * *       /path/to/the/command 2>&1 > /dev/null

because my script runs when I execute it, but in crontab, it doesn't work

Are you sure that it is executed?
Maybe try to put something simple in the same crontab, typically
  /bin/echo "hello" > /tmp/hello
to be sure that cron actually treats your command.

An alternative would be:
*/5 * * * *       su - nobody -c "/path/to/the/command"

This is what I intended to write indeed, but the "nobody" got out of the way.

I am also aware that /var/spool/cron/crontabs/nobody is a cleaner solution, but in fact I have some strange behaviors with cron on my DNS:
- no crontab other than /var/spool/cron/crontabs/root is taken in account (no way with /etc/crontab, /var/spool/cron/crontabs/ismora, ...), which led me to the "su -c" trick
- whether I directly edit /var/spool/cron/crontabs/root, or I use "crontab -e" as root, any new line that I add is not executed; I have to kill the crond process then launch another one to have the updates taken in account.
This is different from the cron program behavior I am used to (checking /var/spool/cron/crontabs/ every minute and automatically taking care of new lines or files).
But maybe this is me, maybe I missed something obvious, I realize now that maybe there is some /etc/cron.deny file, and I don't have access to my DNS right now to check.