Upgrading from the command line?

You'll first need to make sure update-manager-core is present (it may already be installed):

sudo apt-get install update-manager-core

Next, run:

sudo do-release-upgrade

You may need to check /etc/update-manager/release-upgrades and change the line:

Prompt=lts

to:

Prompt=normal

for the release to show up.

• Upgrade Documentation
• Upgrade Notes

If you run the command sudo do-release-upgrade -d through SSH then use a GNU Screen, because the upgrade process will turn off SSH -> close the default port and open a new one (it will inform you of this new port), so:

$ ssh USER@HOST

$ screen -S upgrade
$ sudo do-release-upgrade -d

open a new terminal on client computer:

$ ssh -p PORT USER@HOST

$ screen -d
$ screen -r upgrade

You can do

sudo do-release-upgrade

for command line updating

(This is actually the same as for Ubuntu Server)