See bug: #966575 It happens during auto-upgrade on systems with more than one disk (here raid1 /dev/md*) and due to inconsistent installation information in grub-pc:
root@gkmonitor:~# debconf-show grub-pc | grep /install_devices: * grub-pc/install_devices: /dev/disk/by-id/ata-ST2000DM001-1ER164_Z4Z3JAP0 with: root@gkmonitor:~# ls -l /dev/disk/by-id/ insgesamt 0 lrwxrwxrwx 1 root root 9 Mär 5 09:37 ata-ST2000DM001-1ER164_Z4Z3JAP0 -> ../../sdb lrwxrwxrwx 1 root root 9 Mär 5 09:37 ata-ST2000DM001-1ER164_Z4Z3JBQN -> ../../sda lrwxrwxrwx 1 root root 9 Mär 5 09:37 md-name-gkmonitor:0 -> ../../md0 lrwxrwxrwx 1 root root 9 Mär 5 09:37 md-name-gkmonitor:1 -> ../../md1 So automatic upgrade will do grub-install into /dev/sdb and not /dev/sda. Booting from /dev/sda via BIOS will result in error. Fixing it with grub-install /dev/sda. dpkg-reconfigure grub-pc will give the option to select all disks, resulting in: root@gkmonitor:~# debconf-show grub-pc | grep /install_devices: * grub-pc/install_devices: /dev/disk/by-id/ata-ST2000DM001-1ER164_Z4Z3JBQN, /dev/disk/by-id/ata-ST2000DM001-1ER164_Z4Z3JAP0 On next upgrade, the grub-install script will hopefully upgrade all disk MBRs Regards, Bernd
