I’ve been running 10.04 in my office running two servers. One a NAS, E-MAIL, DHCP server. This was working great and was solid and bug free.
Than one day I upgraded the backup server to 12.04. Its been hell ever since. First the upgrade failed on the GRUB update. It’s never great when you upgrade and the server doesn’t boot. You then pull your hair out getting a live CD to restore GRUB.