snapreader is a delta extractor and merger for the dmsetup target snapshot. Its a study purpose project, and can serve as base for many others crazy projects involving extracting the differences between devices and merging it back into the original device (if wanted).

Fork it and test it, theres some scripts included to facilitate testing, and only one machine is required.

Have fun!!

WARNING: 
YOU'LL NEED ROOT ACCESS TO DO THE TESTS. SO TAKE CARE!

[root@umago snapreader]# cd scripts

[root@umago scripts]# ./create_files.sh

...

SUCCESS: Files created

[root@umago scripts]# sh setup_loops.sh

SUCCESS: Loops are ready

[root@umago scripts]# mount /dev/mapper/snap /media

[root@umago scripts]# vim /media/some_data

Write something...

[root@umago scripts]# umount /media

[root@umago scripts]# sh remove_loops.sh

SUCCESS: Loops were removed

[root@umago scripts]# cd ../source

[root@umago source]# ./snapreader -d ../scripts/cow_device

[root@umago source]# ls delta

delta

[root@umago source]# ./snapreader -m delta ../scripts/main_device

Let's test the merge :)

[root@umago source]# losetup /dev/loop1 ../scripts/main_device

[root@umago source]# mount /dev/loop1 /media

[root@umago source]# ls /media/some_data

/media/some_data

[root@umago source]# umount /media

[root@umago source]# losetup -d /dev/loop1

Yeah it works!

snapreader is distributed under the terms of the GNU General Public License, version 2. See the COPYING file for more information.

Lucas Alvares Gomes (aka umago) [email protected]

1. Fork it
2. Create a branch (git checkout -b <branch name>)
3. Commit your changes (git commit -am "Added ...")
4. Push to the branch (git push origin <branch name>)
5. Create an Issue with a link to your branch