cron runs scheduled commands. FreeBSD also ships periodic, a framework of maintenance scripts that cron runs daily, weekly and monthly, emailing a report to root.
1Per-user crontabs
crontab -e # edit your crontab
crontab -l # list itFields are minute, hour, day of month, month and day of week, then the command. Cron uses a minimal environment, so use full paths.
# m h dom mon dow command
15 2 * * * /usr/local/bin/rsync -a /home/alice/docs/ /backup/docs/
*/10 * * * * /home/alice/bin/check.sh >/dev/null 2>&1
@reboot /home/alice/bin/on-boot.sh2System crontab
/etc/crontab has an extra user field. Rather than editing it, packages and admins can drop files into /usr/local/etc/cron.d/ using the same format.
# /usr/local/etc/cron.d/zfs-snap
SHELL=/bin/sh
PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin
0 * * * * root zfs snapshot -r zroot/data@hourly-$(date +\%Y\%m\%d\%H)In crontab files, % has a special meaning and must be escaped as \%.
3periodic
The scripts live in /etc/periodic/{daily,weekly,monthly,security} and /usr/local/etc/periodic/. Defaults are in /etc/defaults/periodic.conf; override them in /etc/periodic.conf.
sysrc -f /etc/periodic.conf daily_scrub_zfs_enable=YES
sysrc -f /etc/periodic.conf daily_status_zfs_enable=YES
sysrc -f /etc/periodic.conf daily_output=/var/log/daily.log # log instead of mailing
periodic daily # run it now to test4Reading the reports
By default reports are mailed to root locally. Read them with mail, or forward root's mail by setting root: in /etc/mail/aliases (then run newaliases), or log to files as above.