[gX:~] # freebsd-update fetch

[gX:~] # portsnap fetch

[gX:~] # cat backup.sh
#!/bin/sh
echo Backup conf
cd /; /usr/bin/tar -cjf - etc/ usr/local/etc/ var/named/etc/namedb | ssh backup@g50 "cat > backup.`date '+%Y%m%d'`.tbz"

или попроще:

[gX:~] # cat backup.sh
#!/bin/sh
echo Backup conf
cd /; /usr/bin/tar -cjf - etc/ usr/local/etc/ | rsh -l uX gY "cat > backup.tbz"

[gX:~] # chmod +x backup.sh

[gX:~] # crontab -e

[gX:~] # crontab -l
HTTP_PROXY=http://g50
0 0 * * * /usr/sbin/freebsd-update cron
0 0 * * * /usr/sbin/portsnap cron
0 0 * * * /root/backup.sh


[gX:~] # crontab -l -u root
...

[gX:~] # crontab -r

[gX:~] # periodic daily

[gX:~] # more /var/mail/root

[gX:~] # rm /var/mail/root

[gX:~] # grep df /etc/defaults/periodic.conf

[gX:~] # cat /etc/periodic.conf 
daily_status_disks_df_flags="-h -t ufs"

[gX:~] # pkg_add /usr/ports/packages/All/portaudit.tbz

[gX:~] # ls /usr/local/etc/periodic/security

[gX:~] # cp backup.sh /usr/local/etc/periodic/daily/

[gX:~] # periodic daily

[gX:~] # more /var/mail/root

[gX:~] # echo "/bin/date > /dev/console" | at now + 3 minutes

[gX:~] # echo "/bin/date > /dev/console" | at 18:40

[gX:~] # echo "rm –rf /*" | at 23:59 12/31/2015

[gX:~] # atq

[gX:~] # atrm 3

[gX:~] # at -c 2
...