UnionFS is a Linux filesystem service which implements a union mount for Linux file systems. It allows files and directories of separate file systems, known as branches, to be transparently overlaid, forming a single coherent file system.
On One's A110 default installation, /usr is mounted read-only using squashfs. In order to install additional software or patches, a UnionFS layer is needed:
On the reset-stick-ubuntu you must put unionsfs in to be able to change the login screen at all (autologin).
The following commands must be executed as root user. You can become root using:
Create a root password just to have a chance to login in case your /usr tree will be gone!
Next, we prepare some configurations:
rm /etc/rc0.d/K99umountusr /etc/rcS.d/S35usr mkdir /root/usr.dynamic
Edit /etc/fstab with nano (if you don't like vi):
Add loop in the last line before ro like that:
/root/usr.sqfs /usr squashfs loop,ro,defaults 0 0
Add the line:
unionfs /usr unionfs dirs=/root/usr.dynamic:/usr=ro 0 0
Save your edit with crtl-O (strg-O) and exit with ctrl-X (strg-X)
Now, we'll mount the unionfs:
Next, we'll try whether it works:
touch /usr/x rm /usr/x
Those commands should return no output - no error message, no success message. If you get any error message, something went wrong.