This is a simple script that I use to backup family photos, doc, and other media from the NAS to an external drive.
usage: nas_backup.sh <filelist>
$ cat filelist.txt
/path/to/src_0/ /path/to/dest_0
/path/to/src_1/ /path/to/dest_1
...
/path/to/src_n/ /path/to/dest_n