We need to see your /var/log/syslog to be sure but it looks like you have a drive failure. If you can capture the detailed errors in the syslog, post them here.
** Changed in: grub2 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1375997 Title: ERROR: pdc: reading /dev/sda[Input/output error] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1375997/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs