[libvirt-users] Hotplug/hotadd functionality of libvirt?

[David Mansfield]

On 01/03/2012 01:31 PM, Michal Privoznik wrote:
> On 03.01.2012 14:39, Kees van Reeuwijk wrote:
>> Hello,
>>
>> First of all, happy new year!
>>
>> I am interested in the hot plugging facilities of libvirt, in particular
>> in what qemu calls 'hot add' of network interface cards. (And also the
>> reverse: hot unplugging/removing of NICs.)
>>
>> I think I am overlooking something, but so far the best I have been able
>> to find is:
>>
>> http://libvirt.org/sources/virshcmdref/html/
>>
>> and it is not entirely clear to me what the relevant virsh commands are.
>> The most obvious choice seems to be the iface-* commands such as
>>
>> http://libvirt.org/sources/virshcmdref/html/sect-iface-define.html
>>
>> but these seem to be about physical rather than virtual network
>> interfaces, and the documentation `needs to be written' anyway, and from
>> the copyright notice the manual seems to be somewhat outdated by now.
>>
>> Can you give me a little help with this? Is such hot plug/add
>> functionality supported by libvirt in the first place? Is there some
>> kind of overview document about this? What is the most authoritative
>> documentation of this functionality? Is there a Java or C API to access
>> this functionality?
>>
>> Thank you for any help you can give me,
>>
>
> I think virsh attach-interface / detach-interface is what you are
> looking for. Another option is to write a little XML snippet and virsh
> attach-device it.
>


Additionally, I can vouch for at least a centos6 guest being able to 
properly respond to hotplug/remove for virtio NICs.  It automatically 
runs the ifup for the interface as long as the MAC address is correct. 
I imagine this works for other O/S as well.  I add/remove using 
virt-manager (which uses libvirt) so I don't know the specific virsh 
command...

David