Use unison to keep to directories synced. I use unison to keep my home server synced with my laptop.

Install unison using apt-get on both computers/servers from shell as root.

$ apt-get update
$ apt-get install unison

Create a directory .unison in you home path, if it does not already exist.

Create a file in ~/.unison/mysync.prf

# Unison preferences file
root = /home/mikkel/Documents
root = ssh://priv_mikkel@hydrogen.notfound.dk//home/priv_mikkel/Documents

Now run unison like as your user

$ unison mysync

This will sync the two paths.