Bug#984426: Possible manual fix with install/configuration issue

[Dr. Bernd Zimmermann]

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 at gkmonitor:~# debconf-show grub-pc | grep /install_devices:
* grub-pc/install_devices: /dev/disk/by-id/ata-ST2000DM001-1ER164_Z4Z3JAP0

with:

root at 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 at 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