Re: [libvirt-users] [Qemu-devel] Using virsh to load scripts for the guest machine
Eric Blake <eblake(a)redhat.com> writes:
On 07/30/2012 12:00 PM, Mauricio Tavares wrote:
> On Mon, Jul 30, 2012 at 1:50 PM, Eric Blake <eblake(a)redhat.com> wrote:
>> On 07/15/2012 07:52 PM, Mauricio Tavares wrote:
>>> Right on the top of
>>>
http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-...,
>>> it seems to imply you can load/send scripts to the vm guest using virsh.
>>> Is that possible? How and what are the limitations? Can you query the vm
>>> guest?
>>
>> What type of scripts are you talking about? You may be thinking more
>> about the capabilities of what libguestfs provides, for modifying disk
>> images. In general, virsh itself controls how to start a guest, but not
>> the additional layers of communication (such as virtio, qemu-ga, or the
>> libguestfs appliance app) required for a host to command a guest to do
>> something from within the guest.
>>
> Basic one would be in case a machine has been paused for a long
> time. You know as in "hey, you lazy vm! You have been sleeping for two
> weeks! Now your clock is way off and poor ntp can't sync it back. So,
> here's current date!"
That is something that fits better through qemu-ga, but no one has
implemented it yet (cc'ing qemu-devel in case I'm misrepresenting
things). Of course, if we did have a qemu-ga command for pushing the
current time into the guest, then libvirt could usefully expose an API
to wrap that qemu-ga command.
Could you setup a wiki page on qemu.org with a list of qemu-ga
commands that libvirt would like?
Adding commands is pretty trivial so if ya'll have a list of things
you'd like, they're great quick tasks that we can find folks to work on.
Regards,
Anthony Liguori
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org