Elementary OS, Linux, Ubuntu

Create BTRFS Snapshots With Each apt-get Transaction

So I took it upon myself to fork apt-btrfs-snapshot. It is a program that takes BTRFS snapshots after each apt transaction. I wanted it to use Snapper because Snapper has a GUI. Snapper also abstracts all of the functionality of working with BTRFS snapshots.

Here are some of the things its provides:

  • Management via a GUI
  • Rollbacks without mounting anything
  • A list of what files were changed and their filesizes
  • Tracking of what packages were installed
  • Pre and post snapshots
  • Automatic clean up

You can check it out on github:
https://github.com/agronick/apt-btrfs-snapper

64bit .deb

Ubuntu 14.04 Ubuntu 14.10 Ubuntu 15.04
32bit .deb 32bit .deb 32bit .deb
64bit .deb 64bit .deb 64bit .deb

You can use a tool called gdebi to grab all the dependencies you need, which are only really Python and Ssnapper. If you want this done for you run
gdebi apt-btrfs-snapper_0.4.1_all.deb

Management Via a GUI

You can check out this post on installing Snapper GUI on Ubuntu. As you can see below you get a list of all your snapshots and in the bottom you can see what packages were installed. If you hold down control you can select two snapshots and open up the changes view to see what files were changed.

Snapper-GUI on Ubuntu
Snapper-GUI on Ubuntu

ROLLBACKS WITHOUT MOUNTING ANYTHING

To rollback to a previous version you just type:
sudo apt-btrfs-snapper --restore .
Replace <ID> with the snapshot ID or the snapshot name. This will delete, create, and modify your files to get your machine back in the state that it was in when that snapshot was created. You can then roll forward in time just by using a newer ID. You don’t need to restart anything.

A LIST OF FILES THAT WERE CHANGED AND THEIR FILESIZES

You can get a list of snapshots with:
sudo apt-btrfs-snapper list
You can then see what files were changed between two snapshots with:
sudo apt-btrfs-snapper diff

Here is a sample of that output:

c   391 B      /usr/share/doc/maya-calendar-plugin-caldav/changelog.gz
c   391 B      /usr/share/doc/maya-calendar-plugin-google/changelog.gz
c   391 B      /usr/share/doc/maya-calendar/changelog.gz
c   542 B      /usr/share/doc/pantheon-files/changelog.gz
c   246 B      /usr/share/doc/pantheon-photos-common/changelog.Debian.gz
c   246 B      /usr/share/doc/pantheon-photos/changelog.Debian.gz
c   854 B      /usr/share/doc/plank/changelog.Debian.gz 

You can use snapper itself to restore an individual file to a specific state.

Tracking of what packages were installed

apt-btrfs-snapper saves the names of all the packages that were installed in the user data of each snapshot. The best place to view this is in snapper-gui. It can be viewed in the snapper command line tools but it is hard to read. You can see this in the bottom pane in the screenshot above.

Pre and post snapshots

apt-btrfs-snapper takes a snapshot before and after each transaction. They are grouped together in snapper-gui. You can easily see what changes took place between the two snapshots.

Automatic clean up

One of the best parts about snapper are the clean up algorithms built into it. apt-btrfs-snapper simply uses the configuration settings set for the number cleanup algorithm which is part of snapper.

So check it out. Its stable, works great, and makes taking and manipulating BTRFS snapshots a lot easier.

Linux

Installing Snapper-GUI on Ubuntu: A GUI for BTRFS Snapshots

Snapper GUI is a great program and one you absolutely need if you are using Snapper on a desktop. Snapper is a program that helps manage snapshots on the btrfs filesystem. This quick guide will go over how to install it on Ubuntu.

Snapper-GUI on Ubuntu
Snapper-GUI on Ubuntu

Run the following in a terminal.

First install the packages you will need to run:
sudo apt-get install python3 libgtksourceview-3.0-1 python3 python3-dbus python3-setuptools git

Then clone the snapper-gui GIT repo somewhere:
git clone --depth=1 https://github.com/ricardomv/snapper-gui.git

cd into the snapper-gui folder GIT created and run:
sudo python3 setup.py install

Now run the program:
snapper-gui

If you haven’t made a config with snapper first run:
snapper create-config /

Now that you have it installed you can use apt-btrfs-snapper to take a snapper snapshot every time you do an apt-get transaction.

Bash Scripts, Linux

Get the size of your BTRFS Snapshots

If you want to get the size of your BTRFS snapshots you would probably use btrfs qgroup show.  This only shows you a list of IDs and the sizes are in bytes. I wrote a script that will convert the sizes from bytes to kilobytes, megabytes or gigabytes. It will combine the IDs with the name of each snapshot or subvolume from btrfs subvolume list to make each row a lot more meaningful.

In the end instead of seeing a list like this:
Screenshot from 2015-05-26 15:47:24

You’ll see:

Detailed information of each BTRFS snapshot
Detailed information of each BTRFS snapshot

Instead of meaningless IDs you now have the name of your BTRFS subvolumes or snapshots. Instead of a hard to decipher string of bytes it converts each amount into the most appropriate unit of measurement. You can also see the total amount of data that is being used by the snapshots.

For this to work you first need to enable  quotas. Run this command to enable quotas if you haven’t done so already:

sudo btrfs quota enable /

You can clone the project from github by running:
git clone https://github.com/agronick/btrfs-size.git

Or you can just go a wget on the script:
wget https://raw.githubusercontent.com/agronick/btrfs-size/master/btrfs-size.sh

Set it to executable with:
chmod +x ./btrfs-size.sh

Now you can just run the script with: ./btrfs-size.sh

All the columns are pretty self explanatory. The Total column will tell you how much data is in that BTRFS subvolume. The Exclusive Data column is how much data is exclusive to that subvolume. Since BTRFS is a “copy on write” filesystem none of the data is replicated when you create a snapshot. It only needs to make a copy when something changes.

Leave your feedback here to let me know how it worked for you.