I wrote a task script for automatic alarm, but he did not work.
but, Manual execution is working, I do not know which link is wrong.
Thank you.
~# ps aux | grep cron
root 452 0.0 0.0 29008 2924 ? Ss 00:16 0:00 /usr/sbin/cron -f
root 11968 0.0 0.0 14224 960 pts/0 S+ 10:34 0:00 grep --color=auto cron
~# crontab -l
MAILTO=mail@mail
15 3 * * 7 letsencrypt renew
*/2 * * * * root /opt/disk-alarm/disk_alarm.sh > /dev/null 2>&1