UnionFS
From A110 Wiki
This Howto is based on this thread. It's an optimized version of the instructions given in the two postings JeLuF am Do 29. Mai 2008, 20:55 and Gast am Do 29. Mai 2008, 21:18.
It has not yet been tested in its final form. Your feedback is welcome! Please read the discussions to this page too.
Tested by User:Andreas 10:29, 4 June 2008 (UTC), works with added loop option in /etc/fstab!
If you have done it before without loop option you can repair it with nano, boot the rescue system and add the loop option in fstab. and mount -a.
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:
sudo -i
Create a root password just to have a chance to login in case your /usr tree will be gone!
passwd
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):
nano /etc/fstab
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:
mount -a
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.
