http://askubuntu.com/questions/360598/13-10-black-borders-black-terminal

https://wiki.ubuntu.com/Mir/Installing

Removing the system-compositor-testing PPA

Should you have been using the system-compositor-testing PPA you will have to remove the PPA and it's content from your system prior to installing XMir from archive.

$>sudoapt-getupdate
$>sudoapt-getinstallppa-purge
$>sudoppa-purgeppa:mir-team/system-compositor-testing
$>sudorm/etc/apt/preferences.d/50-pin-mir.pref

Then,follow "Installing from Archive".

Installing from Archive

Prior to landing Mir and related packages in the Ubuntu archive,we offered XMir via the system-compositor-testing ppa (ppa:mir-team/system-compositor-testing). As of August 9,2013 XMir can be installed directly from archive via

$>sudoapt-getupdate
$>sudoapt-getdist-upgrade
$>sudoapt-getinstallunity-system-compositor
$>sudoapt-getinstallubuntu-desktop-mir
$>sudorestartlightdm

Verifying that unity-system-compositor is running

You can check in 3 ways whether unity-system-compositor is running:

$>psaux|grepunity-system-compositor
$>grep-ixmir/var/log/Xorg.0.log
$>ls-l/var/log/lightdm/unity-system-compositor.log

Removing unity-system-compositor

Temporarily

If you want to temporarily switch back to using X.org on your system,run following commands:

$>sudovi/usr/share/lightdm/lightdm.conf.d/10-unity-system-compositor.conf

and add a comment to the second line:

[SeatDefaults]
#type=unity;xlocal

and restart lightdm

$>sudorestartlightdm

If you want to enable XMir back again,you simply remove the comment:

[SeatDefaults]
type=unity;xlocal

and restart lightdm

$>sudorestartlightdm

Permanently

In order to remove unity-system-compositor permanently from your system,run following command:

$>sudoapt-getremoveunity-system-compositor
$>sudorestartlightdm