Abstract - last modified 2019-03-09

Fix limitations of the original Linux Mint LMDE 3 (debian edition) installer contained with the current lmde3-iso to create a timeshift conformant btrfs-setup using /@ and optional /@home sub-volumes.

Use at your own risk - you have to read and accept the disclaimer

1 - Backup data

Backup any important data. To use sub-volumes on btrfs will require you to reformat the root-filesystem. A dedicated btrfs /home -partition could be reused without formatting, but the original data will be located "outside" the regular file-structure on the running install and require extra steps to move related files to the /@home -sub-volume later. Thus in the following it's assumed the install will replace existing data.

2 - live-lmde3 - preparations

Create a bootable lmde3 media (dvd or usb stick) and boot it.

In case you are not using an us-English keyboard, you should configure your keyboard-layout using Menu->Preferences->Keyboard. Switch to the "layout" section of the shown dialog and add yours there using the "+" button.

Close the dialog and switch the keyboard layout by clicking onto the small country-flag in the panel-tray on the lower-right.

Open a terminal update the current package list and install git to be able to grab the files of the updated installer.

apt update
apt install git

3 - download modifications

Starting in the mint users home-directory, download the live-installer from git and switch into the live-installer directory afterwards.

cd
git clone http://github.com/linuxmint/live-installer
cd live-installer

As the original pull-request has been merged to the master-branch in the meantime, the following alternative can be skipped (normally)! BUT - as there might be other (conflicting) merges get added later on, one could try to grab the original modification for btrfs-support explicitly only:

# USE ONLY IN CASE OF CONFLICTS !

cd
git clone http://github.com/linuxmint/live-installer
cd live-installer
git fetch origin pull/94/head
git checkout -b pullrequest FETCH_HEAD

Replace original files with the updated versions.

vp="usr/lib/live-installer"
sudo cp $vp/frontend/gtk_interface.py /$vp/frontend
sudo cp $vp/installer.py /$vp
sudo cp $vp/partitioning.py /$vp

4 - perform the setup

Launch the installer using the desktop-icon. Follow setup-pages until you reach the partitioning section.

Prepare your partitions as needed using the partition-options = re-use existing ones or add partitions for your root-volume and optional for a separate home-volume.

5 - assign @ and @home

Select the root-partition, right-click onto it and select "Edit" to get access to the additional subvolume-options. Select /@ as mountpoint (instead of / ) from the available selections. Select "format as btrfs" (is obligatory for the root-fs).

Optional, if you are using a separate btrfs-partition for your home-directory: Select the home-partition and assign it to /@home as mountpoint (instead of /home ) the same way. If the partition is already using btrfs and does contain preexisting data, (which you want to recover later) you could leave the format-option empty (as the format-option is optional for a home-partition).

6 - continue setup

After assignment of other partitions as needed, continue the setup and finish the install. The installed lmde3 should now offer a working btrfs-option with timeshift.

Good luck - have fun