vm with fc 14 won't boot after last kernel update

[Barry]

On Sat, 16 Apr 2011 07:26 -0400, "Tom H" <tomh0665 at gmail.com> wrote:
> On Wed, Apr 13, 2011 at 8:55 AM, Barry <txscope at fastmail.fm> wrote:
> > On Wed, 13 Apr 2011 01:01 -0400, "Tom H" <tomh0665 at gmail.com> wrote:
> >> On Tue, Apr 12, 2011 at 8:02 PM, Barry <txscope at fastmail.fm> wrote:
> >> >
> >> > I had an instance of FC 14 running in a kvm vm on a centos 5.6 box.
> >> > After updating the kernel today, that vm refused to boot. I'm bumped
> >> > into a grub menu. Grub doesn't seem to be able to find the boot image or
> >> > the root partition. There are two othere vm instances (FC 13, and Winxp)
> >> > that are fine.
> >>
> >> You might have run into a 5.6 bug. Are the F13 and WinXP images of
> >> type qcow2 and the F14 image of type raw?
> >
> > That's  good question. I used the default settings in Virtmanager and
> > created all the easy way, so I suppose that they are all raw.
> >
> > Looking at the xml files in /etc/libvirt/qemu, both the problem FC14 and
> > the working FC13 vms have no type listed in the driver spec.
> >
> > The Winxp and a new FC14 instance (created last night and working fine)
> > have a type listed as 'raw'.
> >
> > I don't know where else to look for the type.
> >
> > I just updated the host to Centos 5.6 on the weekend, and I restarted
> > the machine then, and therefore, restarted the vms as well, and all
> > three of the vms fired up. It was only when I updated the FC14 vm that I
> > ran into the problem.
> 
> I thought that with the latest version, if there's no type specified,
> raw's assumed for some reason. So if the type's qcow2, it fails.

I saw some discussion of that, but the problem FC14 does start to boot.
It jumps right to grub where it gets stuck. I think the vm image must be
messed up.

I thought I might be able to boot into an earlier kernel by entering the
commands in grub. I can find the vmlinuz files, and the initrd image,
but I don't know how to point grub to the root system. It's using LVM
and I'm not sure how to construct the pointer. It looks like it should
be "root=vg_MACHINENAME-lv_root" but one really dumb thing is that I
cannot recall the name. I've tried a few variations and it never finds
root

I tried to see the grub.conf, but 'cat /boot/grub/grub.conf' showed me
an empty file. 

As a last resort, I can delete image and start again. Anything important
is saved. 


> 
> But that doesn't explain why your F13 VM's OK.
> 
> >From the CentOS archive:
> http://lists.centos.org/pipermail/centos/2011-April/109595.html
> -- 

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