Bug#351768: Installation report: lilo fails with "mapped boot device cannot be on multiple real devices" (LVM2)

[Frans Pop <aragorn@tiscali.nl>]

On Tuesday 07 February 2006 11:29, Chris Carr wrote:
> So I chose lilo, and it failed. Checking Alt-F4 showed the error
> "mapped boot device cannot be on multiple real devices". I can only
> find two references to this on google (none in the Debian mailing list
> archives or BTS), both in old patches from times when lilo didn't yet
> work with libdevmapper:

This sounds like a limitation in lilo, not in the installer as the message 
you cite is not produced by the installer.

The basic problem probably is that the bootloader needs physical access to 
the /boot directory before the LVM is assembled. If /boot is on an LVM 
which is split over 2 physical devices, the bootloader cannot be sure 
that all files in /boot will be on the same physical device and thus it 
refuses to install.

I have no idea if this can be resolved.

The obvious solution is to create a (small) separate /boot partition 
_outside_ the LVM volume.

Cheers,
FJP