[Pkg-xen-devel] Bug#612237: Bug#612237: xen-hypervisor-4.0-amd64: Fails to boot after upgrade from lenny

[Ian Campbell]

On Mon, 2011-02-07 at 13:44 +0100, Michael Vogt wrote:
> Hey,
> Unfortunately it rebooted before writing any logs. I just have this 
> screenshot (which actually
> shows XEN 3.X, for XEN 4 the screen just turns black and then it 
> reboots, but I think its the
> same error).

You might find "noreboot" on the hypervisor command line or a serial
console, as described at 
http://wiki.xen.org/xenwiki/XenSerialConsole , lets you see the
messages.

There are more debugging options mentioned under "Are there more
debugging options I could enable to troubleshoot problems with Xen
and/or dom0 kernel?" in http://wiki.xen.org/xenwiki/XenParavirtOps

> I used the 2.6.32-5-xen-amd64-kernel from squeeze. The old 
> 2.6.26-2-kernel didn't even
> boot without XEN.

2.6.26 was a class-Xen kernel so it wouldn't be expected to boot without
Xen

> xen-linux-system-2.6.32-5-xen-amd64 is 2.6.32-30

This is pvops so should work with or without Xen.

> As I stated in my first mail, there were some projects running on the 
> server. With a backup I now restored lenny with running XEN because I actually need the server. 
> So right now I can't test any modifications,

Sure.

> but I'll try to reproduce this error on a local machine.

Thanks.

> ### BEGIN /etc/grub.d/20_linux_xen ###
> menuentry 'Debian GNU/Linux, with Linux 2.6.32-5-xen-amd64 and XEN 
> 4.0-amd64' --class debian --class gnu-linux --class gnu --class os 
> --class xen {
>          insmod raid
>          insmod mdraid
>          insmod part_msdos
>          insmod part_msdos
>          insmod ext2
>          set root='(md1)'
>          search --no-floppy --fs-uuid --set 
> cd90240f-1eae-47f7-9c2b-7c52baa56911
>          echo    'Loading Linux 2.6.32-5-xen-amd64 ...'
>          multiboot       /xen-4.0-amd64.gz
>          module  /vmlinuz-2.6.32-5-xen-amd64 
> root=UUID=a82eced9-edf5-4a73-9b81-6895f4683b2e ro  quiet
>          echo    'Loading initial ramdisk ...'
>          module  /initrd.img-2.6.32-5-xen-amd64
> }

This, and the other Xen entries, are of a form which suggests you are
suffering from an issue with grub2 whereby Xen eats the first option to
each multiboot module. (grub2 subtly changed the multiboot semantics
compared with grub1) In this case that is the "root=UUID=..." 

This is described under "Booting Xen with GRUB2 fails?" at
http://wiki.xen.org/xenwiki/XenCommonProblems

Since Squeeze has a fix for this issue the above should contain
"placeholder" at the start of each command line. Since you do not have
this I guess either you are not running Squeeze's version of grub2 or
you have a bunch of /etc/grub.d/*.dpkg-* which need resolving? Although
perhaps just running "update-grub" will fix the issue.

Ian.

-- 
Ian Campbell
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