I changed the UUID label in Grub in line : kernel /boot/vmlinuz-2.6.20-15-generic root=/UUID=.... by : kernel /boot/vmlinuz-2.6.20-15-generic root=/dev/sda1 ro quiet splash and now it works.
So apparently there are some confusion with UUID labelling -- [Feisty]Bug with kernel 2.6.20 on AMD 64 : no way to boot https://bugs.launchpad.net/bugs/107965 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
