INTERLOCK ROCHESTER BACKUP SCRIPT
2011/01
Ben Woodruff (http://ben.woodruff.ws)

WHAT IS IT?
Motivation
This script was created as a Time Machine-like backup script for use by Interlock members utilizing our offsite backup service (or, anyone else who has such a need).

Sources
It is based on the work of Michael Jakl, and his original ideas can be found on his website: http://blog.interlinked.org/tutorials/rsync_time_machine.html

WHAT DOES IT DO?
Currently the script assumes that you have a hard drive (probably USB) that has an encrypted sparse bundle disk image on it (created through Disk Utility or similar). It creates incremental backups that will appear to contain the entire file structure that you are backing up, but uses very minimal space for files that haven't changed since the last backup. It does this using hard-links to existing files. You can safely delete entire backup sets without losing your data because of that.

WHERE DOES IT WORK?
So far I have only had the opportunity to test on Mac OS X 10.6 Snow Leopard. Ideally it will eventually work on anything loosely UNIX based that has rsync.

WHAT DOESN'T IT DO?
I have no plans to re-engineer rsync. If rsync can't do it, this script won't either. This is just a wrapper.

HOW DO I USE IT?
First open backup.sh in a text editor and change the variables at the top of the script. Then, from the command line, run:
backup local (for a backup to a local hard drive)
backup network (for a backup to an SSH server)