This was fixed in Ubuntu by adding a PATH line: $ cat /etc/cron.d/zfsutils-linux PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
# Scrub the second Sunday of every month. 24 0 8-14 * * root [ $(date +\%w) -eq 0 ] && [ -x /usr/lib/zfs-linux/scrub ] && /usr/lib/zfs-linux/scrub -- Richard
