Please check this:
and this topic: https://serverfault.com/questions/7969/is-there-a-working-linux-backup-solution-that-uses-inotify
Or you can run rsync using cron.
simply the other way round
unlz4 < Lenovo-Win8-sda.dd.lz4 | dd bs=100M of=/dev/sda
please note that
I drop pv command (is that pipe view ?)
if /dev/sda is hosting your running OS, you may not have a coherent backup. (as your file is named win8 I guess it might be OK)
restoring windows might need to set up boot device as well
I've actually solved it on my own. You never know what you can do till you try :-)
It must be safe to run even when all the filesystems are mounted read-write.
dsk_src=/dev/sdc4 # source disk with original timestamps
mnt_src=/mnt/sdc4 # source disk mounted at this path
dsk_dst=/dev/sda4 # destination disk
directory=user/.thunderbird # the ...