Shut down mozilla, look in ~/.mozilla/firefox for a directory called xxx.default, and copy this to a directory called ~/.mozilla/firefox/profile.

On debian/ubuntu

In /etc/rc.local put a line like "rsync -ar /home/yourusername/.mozilla/firefox/profile/* /home/yourusername/.mozilla/firefox/xxx.default"

Create a file /etc/init.d/saveff containing:

#/bin/bash
rsync -ar /home/yourusername/.mozilla/firefox/xxx.default/* /home/yourusername/.mozilla/firefox/profile

Add the following line to /etc/fstab:

tmpfs /home/yourusername/.mozilla/firefox/xxx.default tmpfs defaults,noatime 0 0

Anonymous