crontab -l
*/10 * * * * /home/vavoosid.sh
@reboot /home/vavoosid.sh
root@dm900:~$ cat /var/spool/cron/root
*/10 * * * * /home/vavoosid.sh
@reboot /home/vavoosid.sh
root@dm900:~$ ls -al /var/spool/cron/root
-rw-------    1 root     crontab         57 May 19 15:12 /var/spool/cron/root
root@dm900:~$ systemctl enable crond.service
Synchronizing state of crond.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable crond
 System startup links for /etc/init.d/crond already exist.
root@dm900:~$ systemctl status crond.service
    crond.service - Periodic Command Scheduler
   Loaded: loaded (/lib/systemd/system/crond.service; enabled; vendor preset: enabled)
   Active: active (running) since Do 1970-01-01 01:00:02 CET; 54 years 5 months ago
 Main PID: 234 (crond)
   CGroup: /system.slice/crond.service
                Ç234 /usr/sbin/crond -n