I recently tried booting into the Grub2's menu entry "Ubuntu GNU/Linux, with Linux 3.2.0-24-generic-pae (Recovery Mode) just to see what was there. It booted successfully, but I had no idea what to do after I was there. My question is where can I find some documentation on the recovery mode and what to do if I truly needed to be there. I'm running Ubuntu 12.04.
The recovery mode is normally used when you need an exclusive admin access to your system. You normally go into root shell and recover/repair the system through the command line.