Easy way to restore incremental rsync backup

It is not what you ask for, but you can actually have everyday a full backup with rsync, while it will upload and take as much storage as normal incremental back up. It is done with hard links. I have done a script that automates that and I use it daily on multiple machines. You can grab it with description here: http://okrasz-techblog.blogspot.com/2011/02/backing-up-with-rsync.html

Note - when backup is done it will update last_full_backup.txt with backup directory. This is in case backup was interrupted.

What you seem to be looking for is the --link-dest functionality that is part of rsync. What you seem to describe is exactly how dirvish operates.

The link-dest option creates hard-links from the destination path to another copy of the structure.

With dirvish you perform an initial backup, which just uses rsync.

After that each additional back, is hard-linked to the previous successful backup. Meaning there is no duplication of files. You can directly access any single backup from within the vault, and each backup is a complete and full backup. You can remove previous backups at any time.

Here is a script that you can use to demonstrate.

# create test area
mkdir -p /tmp/backuptest/{source,dest1,dest2,dest3}
for a in `seq 10` ; do dd if=/dev/urandom of=/tmp/backuptest/source/file$a bs=1M count=1; done

# look
find /tmp/backuptest/ -ls ; du find /tmp/backuptest/

# initial backup
rsync -va /tmp/backuptest/source/ /tmp/backuptest/dest1/

# look
find /tmp/backuptest/ -ls ; du find /tmp/backuptest/

# make chagnes
rm /tmp/backuptest/source/file[2-4]
cat /tmp/backuptest/source/file[6-7] >/tmp/backuptest/source/file11

# new backup linked to previous
rsync -va /tmp/backuptest/source/ /tmp/backuptest/dest2/ --link-dest=/tmp/backuptest/dest1/

# look
find /tmp/backuptest/ -ls ; du find /tmp/backuptest/

# make changes
rm /tmp/backuptest/source/file5
cat /tmp/backuptest/source/file[5-7] >/tmp/backuptest/source/file12

# new backup linked to previous
rsync -va /tmp/backuptest/source/ /tmp/backuptest/dest3/ --link-dest=/tmp/backuptest/dest2/

# look
find /tmp/backuptest/ -ls ; du find /tmp/backuptest/

# remove dest1
rm -r /tmp/backuptest/dest1/

# see your dest2, and dest3 are still complete backups for the state at those times.
find /tmp/backuptest/ -ls ; du find /tmp/backuptest/