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Upgrades
Please do not attempt to upgrade your raspberry pi to a newer version of the distribution (for instance, from 15.04 to 15.10) as the underlying kernel is not designed to do this. This process will take a very long time to complete while potentially filling up your SD card to a point where there is no more free space.
It is safer to back up all your data you wish to keep and re-flash the card with the new image. Attempting to upgrade may corrupt the SD card, prevent your installation from booting, or cause severe glitches.
You can, however, install regular updates via the Software Updater utility for your installed software.
Kernel Updates
The same kernel provided by the Raspberry Pi foundation is used in this edition of Ubuntu MATE. As this kernel is delivered like a “firmware” blob, updates are not distributed via the Software Updater or apt-get.
Instead, to update the kernel, open a terminal and run:
rpi-update
Hardware Acceleration
Currently, Hardware accelerated applications are not supported unlike Raspbian. Applicationsthat depend on OpenGL ES libraries or require the GPU will fail to start.
For playing videos, the application omxplayer will be able to do this and is pre-installed. If you are looking to play MPEG-2 or VC-1 video files then you will need MPEG-2 and/or VC-1 licenses from the Raspberry Pi Store.
Enable/Disable X11
For users who are looking to create their own headless “server” using Ubuntu MATE, there is a utility for toggling the graphical environment.
To disable X11 and login via the console:
graphical disable
To enable X11 to restore the Ubuntu MATE desktop:
graphical enable
Changes take effect after a reboot.