Grub Problems

Wanted to upgrade my Debian Lenny on a DomU xen but ran in some trouble:

Searching for GRUB installation directory … found: /boot/grub
warning: grub-probe can’t find drive for /dev/sda2.
grub-probe: error: Cannot find a GRUB drive for /dev/sda2.  Check your device.map.

to fix this problem you simply need to:

echo "(hd0)   /dev/sda" > /boot/grub/device.map
cd /dev
mknod sda b 202 0

The last instruction is to make the node manual.

Now you can run it again