[Fedora-xen] From multi-boot to multi-guest?

[Pasi Kärkkäinen]

On Wed, Dec 06, 2006 at 07:26:45PM -0500, Tom Horsley wrote:
> Xen is mostly of interest to me so I can do development and testing
> on multiple operating systems without rebooting. I already have
> several /boot and root partitions for several OS setup on my machine.
> I can also boot the Fedora Core 6 xen kernel as dom0, but my experiments
> with the redhat virt-manager tool seem to indicate the only way it can
> create new guests is if I want to install more copies of fedora.
> 
> What I'd really like to do is just turn the various /boot and root
> partitions I currently have into guests under Xen. Are there any
> instructions a person starting with absolutely no knowledge of Xen
> can follow to do this?
> 

I haven't used virt-manager (yet) so I don't know if it supports editing the
config file.. or using custom partitions/volumes/files directly.

You need to edit the xen virtual machine (domU) config file, and specify
your selected partitions for the domU. That way domU will only see
the partitions you specified. 

Specify different partitions for each domU.

-- Pasi

> Things I can guess:
> 
> I'll have to change my fstab file in each OS to not mount other
> partitions owned by other OSes.
> 
> I'll have to give them all unique host names and IP addresses.
> 
> Things I have no idea how to imagine:
> 
> How do I setup the network for each guest?
> 
> Is creating the guest just a matter of building a proper config file
> to point to my existing boot and root partitions and pass to xm?
> If so, what the devil goes in the config file (which
> file names are specified relative to the filesystems mounted on
> dom0 and which ones are relative to the domU mountpoints)? Or
> do I need to copy some info out of the existing partitions so
> it lives somewhere on dom0?
> 
> How do I make sure the kernels in the existing boot partitions will
> support paravirtualization? (I have no fancy new Pacifica or
> Vanderpool instructions on my machine).
> 
> What have I missed that will drop me into virtualization hell
> when I try this stuff? :-).
> 
> Thanks for any pointers to get me started! (Speaking of getting
> started - are there any web pages on Xen that are somewhere
> in between the Sunday Supplement and the Phd level - everything
> I find seems to have hype with no content or content that only
> makes sense if I was in at the beginning of the long conversation
> I missed :-).
>