How to install Ubuntu on a Chromebook

Be warned that entering developer mode causes all the data cached on your Chromebook to be automatically wiped. This shouldn’t inconvenience you, since all your data and settings will normally be stored safely in the cloud – it’s just a security measure to prevent someone who doesn’t know your Chrome OS password from booting into a different OS to snoop at your files. If you’ve been working offline, however, it’s worth making sure everything is synced before you switch modes.

How you switch to developer mode depends on your particular model of Chromebook. On Samsung models, it’s done via a switch at the right-hand side of the chassis. On the Acer AC700, the switch is underneath the battery. If you’re using an Acer C7, you enable developer mode by holding down the Escape and Refresh keys while powering on the system, then pressing Ctrl-D to reboot into developer mode.

As long as you’re in developer mode, your Chromebook will start up with a screen warning that “OS verification is turned off”. This screen can’t be disabled: it’s there so you can’t be tricked into running an unauthorised operating system without realising it.

If you press the spacebar from this screen, you’ll be taken to the recovery interface, from where you can reinstall Chrome OS. Press Ctrl-D instead (or wait 30 seconds) and the Chrome OS initial setup window will then appear, asking you to choose language and networking options.

If you’re using an Acer C7 or a Samsung Series 5 550, you can now skip to the next section. For the original Samsung Series 5 and Acer AC700, there’s one more step to take, since these devices have an additional layer of BIOS protection that must be disabled.

This is done from the command line. To access it, hold down Ctrl-Alt and press the Forward Arrow key (that is, the navigation key in the F2 position along the top of the keyboard). At the login prompt, give your username as “chronos”; you shouldn’t be asked for a password but rather presented with a command line. Enter these two lines:

sudo bash
chromeos-firmwareupdate –mode=todev

Once the BIOS mode has been changed, reboot the Chromebook. At the warning, press Ctrl-D once again to access the setup window.

Downloading the script

The script that installs Ubuntu is downloaded from a remote server, as is the operating system itself – so the next thing to do is connect Chrome OS to a wireless network. Select your SSID from the dropdown menu in the setup window and enter the passphrase to get connected. Once this is done, press Ctrl-Alt-Forward Arrow as described previously to switch to the command line, and again log in with the username “chronos” and no password.

Once you’re in, enter this line:

wget http://goo.gl/tnyga

Your Chromebook should now fetch the script and save it to your home directory. (There’s no particular significance to the “tnyga” name – that’s just the string of random characters chosen by Google’s URL-shortening service.) If this command returns a “not found” error, it’s probably because your Chromebook hasn’t yet connected to the wireless network – wait a moment and try again. When the script has arrived successfully, run this command:

sudo bash tnyga

This will kick off the process of installing Ubuntu – or “ChrUbuntu”, as the project is dubbed – on your Chromebook.

Repartitioning your drive

Most Chromebooks come with a 16GB internal SSD. Chrome OS itself uses around 5GB of this space, leaving 11GB of storage for what’s called the “stateful” partition, where your local settings and cached data are stored. Jay Lee’s script automatically shrinks this to make space for your new Ubuntu partition. The ChrUbuntu system needs at least 5GB of space, but you can choose to allocate up to 10GB. We’ve found that 8GB gives Ubuntu enough space to install updates and applications, while still enabling Chrome OS to cache a decent selection of files and apps for offline use. Once you’ve made your selection, the computer will whirr away for a few minutes making the necessary changes.