Incremental backup

We are a web hosting company with (at this point) a small client base. We want to daily backup our files from our main server via ftp. At the moment this happens via cPanel/WHM's backup function, but this takes too much time and resources. We would like to switch to an incremental backup system that would backup the accounts of our clients on a daily basis, and the MySQL-databases several times a day. On the receiving server, we would keep a daily, weekly and monthly version of the files. 1 important detail: we have full access to our main server (a VPS with CentOS), but the options on the receiving server are really limited (simply a ftp login*) (so this would probably require a push, not a pull, of the files). Ideally, there would be an option to select the frequency of the backups on account basis. There is no need for a real (web based) interface to change the settings, a config file is good enough. Additional info / update (2010-06-25): - Copyright: both the worker (you) and the employer (us) can reuse and resell the script. - After some research we found that it's also possible to use SSH (*so not only FTP). - Focus of this project: limit time and resources needed for the backup. At this moment 30GB takes 6 or more hours to archive and send it to the offshore server, and during this process the server experiences an overload. ## Deliverables The optional requirements (settings per account) are what they are: optional. If it takes too much time (and so, money) leave it out! We manage our own VPS, changes can be made.