[Fedora-livecd-list] feasibility of using xen to produce installed system images?

[Tom Lisjac]

On 12/13/06, Jane Dogalt <jdogalt at yahoo.com> wrote:
> In my project, I'm using qemu to generate system images as a non-root
> user.  I've never used xen, as I have yet to discover as trivial a
> usage of it as qemu provides.  (i.e. no configuration, a simple
> commandline, and there you are booting a livecd in a window).

> I'm wondering if any of you, particularly xen leaning redhat folks,
> have considered using it as a sandbox to create installed system images
> in?  E.g. that could then be modified by a script, and rolled into a
> live iso/usbimage?

For doing generic installs, the combination of qemu, kqemu and vde2
would be difficult to beat. In addition to running in user space, as
you pointed out, qemu provides a pure emulation model for a target
processor, bios, network device and video card. The optional kernel
acceleration module raises it's performance to nearly bare metal.

Xen has a different architecture... it's a true hypervisor that
requires a kernel presence and either cpu support for pure
virtualization (vmx:Intel, smx:AMD) or modifications to the guest os.
As a result, it's not very useful for doing arbitrary os image builds
from generic install media. FC6 provides a Xen aware kernel that can
be used with the Virtual Machine Manager to do kickstart vm image
builds. Patched dom0 and guest os kernels are also available from
xensource.com along with a live cd demo.

I'm planning to do a lot more work with Xen. It's fast, efficient and
ideal for consolidating groups of underutilized servers into a few
well provisioned machines. For building portable install images from
generic media, however, qemu will remain my tool of choice.

-Tom