Introduction

This tutorial explains how to upgrade LMDE 1 "Debian" to LMDE 2 "Betsy".

It is assumed that:

• You have a decent experience/knowledge with/of APT
• You are running a supported edition (i.e. either Cinnamon or MATE)
• Your LMDE 1 system is at Update Pack 8 with upgrades
• You didn't upgrade or pin from Debian Testing or Debian Unstable.
• You are not using Romeo (if you are, please disable it prior to upgrading).
• Your init system is sysvinit (i.e. that you did not switch to systemd).

As usual, please make sure to:

• Make a backup (an HDD image/snapshot of your system for instance) so you can restore everything the way it was if something goes wrong.
• Try the live version of LMDE 2 Betsy, to make sure it works well with your hardware (there's a newer kernel, newer libs, newer drivers in there..), at least the way LMDE 1 does for you.

Step 1 - Modify your APT Source

First, we need to point the computer at the LMDE 2 "Betsy" repositories.

As root, edit /etc/apt/sources.list.d/official-package-repositories.list to make it look like this:

deb http://packages.linuxmint.com betsy main upstream import
deb http://http.debian.net/debian jessie main contrib non-free
deb http://http.debian.net/debian jessie-updates main contrib non-free
deb http://security.debian.org jessie/updates main contrib non-free
deb http://www.deb-multimedia.org jessie main non-free
deb http://extra.linuxmint.com betsy main

Step 2 - Update your APT cache

Now, we update the cache (and upgrade repository keyrings) so the computer is aware of what's available in Betsy. In a terminal, type:

apt update

apt install debian-archive-keyring deb-multimedia-keyring

apt update

Step 3 - Install necessary packages before the upgrade

To avoid conflicts during the upgrade, we install a few packages prior to upgrading. In a terminal, type:

apt install sysvinit-core adwaita-icon-theme blueberry

Step 4 (optional) - Turn off your screensaver

In the MATE/Cinnamon settings, it is recommended to turn off anything that might trigger the screensaver. By the time the upgrade is downloaded, the screen might be locked when it's time to upgrade the screensaver itself.. this is usually ok, but you never know, it's better to be safe than sorry :)

Step 5 - Perform the upgrade

Now that we're all ready, we can perform the upgrade. In a terminal, type:

apt dist-upgrade

Review the information in details. In particular pay special attention to the list of packages being removed. If that looks ok, confirm the command and go for it.

Step 6 - Checks

First, check that the upgrade finished completely. Type:

apt dist-upgrade

It should tell you that everything is now up to date. If it doesn't, it means the system isn't fully updated yet.

The command below also is useful, if you're stuck with conflicts and want to resolve the APT cache:

apt install -f

Finally, make sure you've a core set of packages installed, depending on your edition you can perform either of these commands:

apt install mint-meta-debian-cinnamon

or

apt install mint-meta-debian-mate

Step 6 - Reboot

Don't forget to reboot the computer after everything is finished.

Additional info

• When you upgrade package(s) from the current deb-multimedia, the keyring is still old and apt-get says "the following packages cannot be authenticated: .... install? [y/N]. That's ok, just press "y" when asked.
• When asked to keep or overwrite some files in /etc directory, you can answer whatever you want about these files:

  /etc/issue
/etc/issue.net
/etc/xdg/autostart/nm-applet.desktop

  They will be overwritten with Mint-specific data by mintsystem/debian-system-adjustments tandem on the next boot. You can see what's been overwritten in /var/log/mintsystem.log file.
   
• The same applies to /etc/grub.d/10_linux file. However, updating it from upstream will make LMDE entries in GRUB menu look like "LinuxMint GNU/Linux" instead of the intended "LMDE 2 Cinnamon 64-bit (/dev/sdXY)". You can run "sudo update-grub" to fix that if you wish. You need to run it after the upgrade is done and the system is rebooted.
   
• Cinnamon's shutdown/reboot dialog is missing these buttons right after the upgrade (it has only Cancel button). You can logout and then reboot or shutdown via MDM's menu, or just use the command-line tools (sudo reboot/sudo poweroff). It's a one-time issue - it will be gone on the next system boot.
   
• All Cinnamon fonts are changed to Noto after the upgrade, except for "Default font", which was left Sans for some reason. This is easily corrected via the font preferences.
   
• LMDE's mintUpdate (mintupdate-debian package) is automatically replaced by the original mintUpdate (mintupdate package) which is used in the main Mint edition. It is now compatible with LMDE 2. Unlike LMDE's mintUpdate, it won't check for updates automatically on start, but rather will wait for the specified amount of time (30 minutes by default) before doing the first check. It essentially avoids some issues like this one. You can always click on its icon and tell it to check for updates right away.
   
• Both gnome-terminal and gedit are 3.14 (from Jessie repos), not the older versions from Betsy repo. This is due to them being too new in LMDE UP8 repos. If you want, you can try downgrading them to get your system closer to the "official" LMDE 2 installation.
   
• The issue with "/init: 401: /init: touch; not found" message on boot (mentioned here) is present after the upgrade. I'm not sure how serious it is - the system boots fine. There's a discussion about it in Debian mailing list.
• In one of our tests we experienced fonts problems. They failed to render and only squares could be seen instead of text. This was due to fonts-noto not installing properly. If you're facing this issue, open a terminal and type "apt reinstall fonts-noto".

Finding help

• A lot of people performed the upgrade before the upgrade path was officially open. They gathered on the forums, talked about issues (some of which are fixed now) and their solutions. If you're experiencing issues with the upgrade, this should help: http://forums.linuxmint.com/viewtopic.php?f=242&t=192201
• Also as usual, don't hesitate to connect to the IRC and seek help on the #linuxmint-help channel (irc.spotchat.org).