I wrote this a long time ago. I've since moved on. But for posterity I've moved it off codecollector.net.

CRIBBS.sh

#!/bin/bash
 
#######################################################
# CRIBBS -- Cron Rsync Incremental Backup Bash Script #
# AUTHOR: Adam Merrifield <http://adam.merrifield.ca> #
#			(and countless sources from the web)      #
# DATE: 05-26-11 23:17                                #
# VERSION: 1.0.0                                      #
#######################################################
 
##################
## INSTRUCTIONS ##
##################
 
# You'll need:
# - a remote server running rsync
# - the ability to create an ssh key pair
#		between here and there
# - time
# - patience
 
# Step 1: read up on the stuff you don't know.
# Step 2: establish an ssh public key pair with your server
# Step 3: save this script as a .sh or .command file
#		  someplace on your computer
# Step 4: edit the variables accordingly and save
# Step 5: establish a cron job with this saved file
# Step 6: bask in the glory of CRIBBS
 
 
##########
## HELP ##
##########
 
# For rsync help:
# http://rsync.samba.org/ftp/rsync/rsync.html
 
# For crontab help:
# http://pubs.opengroup.org/onlinepubs/9699919799/utilities/crontab.html
 
# For ssh-keygen help:
# http://www.openbsd.org/cgi-bin/man.cgi?query=ssh-keygen&sektion=1
 
###############
## VARIABLES ##
###############
 
# [EDIT] Local directory to be backed up
# hint: best to include the trailing "/"
LPATH=/Users/name/
 
# [EDIT] Local files and directories to exclude
# hint: the exclude file should contain one directory/file per line
XPATH=/Users/name/someplace/exclude.file
 
# [EDIT] Local key
# hint: must match contents of ~/.ssh/authorized_keys on remote server
LKEY=/Users/name/someplace/some-key-name
 
# [EDIT] Remote login name 
# hint: this would "adam" in adam@10.0.1.3
RUSER=username
 
# [EDIT] Remote backup server name
# hint: this would "10.0.1.3" in adam@10.0.1.3
RHOST=servername
 
# [EDIT] Remote directory where you want backups to occur
# hint: best to leave off the trailing "/"
RBASE=/home/name
 
# [EDIT] rsync options
# hint: do not edit unless you know what you're doing
ROPT="-azprvP --delete --delete-excluded --exclude-from=$XPATH --modify-window=2 --force --ignore-errors --stats"
 
#################
## DO NOT EDIT ##
#################
 
# Remote current path to test against
RCURRENT=$RBASE/current
 
# date
date=`date "+%Y-%m-%d-T%H_%M_%S"`
 
# Remote full progress path
RSSHPROGPATH=$RBASE/previous/incomplete_back-$date
 
# Remote full completed path
RSSHCOMPPATH=$RBASE/previous/back-$date
 
# Remote login
RLOGIN=$RUSER@$RHOST
 
# Remote full rsync path
RSYNCPATH=$RLOGIN:$RSSHPROGPATH
 
# Make "previous" directory
ssh -i $LKEY $RLOGIN "[ -d $RBASE/previous ] || mkdir $RBASE/previous"
 
# rsync backup command
rsync $ROPT -e "ssh -i $LKEY" --link-dest=$RCURRENT $LPATH $RSYNCPATH
 
# shuffle backups around
ssh -i $LKEY $RLOGIN mv $RSSHPROGPATH $RSSHCOMPPATH
ssh -i $LKEY $RLOGIN rm -f $RCURRENT
ssh -i $LKEY $RLOGIN ln -s $RSSHCOMPPATH $RCURRENT