[virt-tools-list] VM GenerationID support in virt-what

Richard W.M. Jones rjones at redhat.com
Tue Jul 1 22:20:32 UTC 2014

On Mon, Jun 30, 2014 at 04:57:09PM +0000, Charles Tonkinson wrote:
> Microsoft have introduced Virtual Machine Generation
> ID<http://go.microsoft.com/fwlink/?LinkId=260709> as a way of
> detecting cloning of a virtual machine. Currently Hyper-V, VMware
> and XenServer all support GenerationID. When Redhat Linux runs as a
> guest of a hypervisor that supports VM GenerationID, it would be
> helpful for virt-what to be able to extract the GenerationID
> value. Are there any plans to do this?

I think MSFT's reasoning is bogus.  What MSFT should have implemented
is a virtual source of randomness, like virtio-rng.  Or (as a backup,
because virtio-rng is better) a way to seed templates with randomness,
like virt-sysprep, virt-customize and virt-builder can do.

Patches to virt-what to detect the VM Generation ID are welcome.  From
the document linked to, it looks as if this is exposed through ACPI,
and thus available to the guest kernel.


Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.

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