Hetzner/popeye/zfssnap.sh

#!/bin/sh
SNAPDATE=`date "+%y%m%d"`
ZROOT="zroot"
ZFS="/sbin/zfs "
# Seven day ago
# -------------

SEVEND=`date -j -v"-7d" +"%s"`

for z in ROOT usr usr/home JAILS 
do
	echo "Creating snapshot tree at "${ZROOT}"@"${SNAPDATE}
	${ZFS} snap -r ${ZROOT}/${z}@${SNAPDATE} 
	if [ ${?} -ne 0 ]; then
		echo  "unable to create a snapshot for ${ZROOT} at ${SNAPDATE}."
	fi

	echo "Cleaning " ${ZROOT}/${z} "snapshots."
	for i in `${ZFS} list -d 1 -H -t snap -o name -r ${ZROOT}/${z}`  
	do
		SNAPCREATED=`${ZFS} list -Hp -t snap -o creation ${i}`
		if [ ${?} -eq 0 ] 
		then
			di=`expr ${SNAPCREATED} - ${SEVEND}`
			if [ ${di} -lt 0 ] 
			then
				echo "removing " ${i}
				${ZFS} destroy -r ${i} 
			fi
		fi
	done

done