#!/bin/sh
mv /mnt/pool/backup/root_latest.img.gz /mnt/pool/backup/root_$(date +%s).img.gz.old
dd if=/dev/da8 conv=sync,noerror bs=64k | gzip -c > /mnt/pool/backup/root_latest.img.gz
find /mnt/pool/backup/*.old -mtime +30 -exec rm {} \;

# Please improve it