FreeBSD with ZFS backup incremental

backup_incremental.sh

#!/usr/local/bin/zsh

PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin 
DATE=$(date "+%Y-%m-%d_%H-%M-%S")

SCRIPTNAME=$(basename $0)
PIDFILE=/var/run/${SCRIPTNAME}.pid


if [ -f ${PIDFILE} ]; then
		#verify if the process is actually still running under this pid
		OLDPID=$(cat ${PIDFILE})
		RESULT=$(ps A | grep ${OLDPID} | grep ${SCRIPTNAME})

		if [ -n "${RESULT}" ]; then
		    echo "${DATE}: Script already running (PID: ${OLDPID})! Exiting"
		    exit 255
		fi
fi

#grab pid of this process and update the pid file with it
PID=$$
echo ${PID} > ${PIDFILE}

echo "${DATE}: start incremetal backup"

LASTSNAPSHOT=`ssh travos "zfs list -t snapshot -o name -s creation -r tank | awk 'END{print}'"`
echo "${DATE}: the last snapshot was: $LASTSNAPSHOT"

#snap teh shot .__.
zfs snapshot -r tank@$DATE

echo "${DATE}: the new snapshot is:   tank@$DATE"

START=$(date +%s)
#send it
zfs send -R -i $LASTSNAPSHOT tank@$DATE | ssh -C -c blowfish-cbc,arcfour travos "zfs receive -F tank"
END=$(date +%s)


TIME=$(( $END - $START ))
echo "${DATE}: It took ${TIME} seconds to send the snapshot"

if [ -f ${PIDFILE} ]; then
    rm ${PIDFILE}
fi