Mailing List Archive

Re: [Xen-users] Xen live migration: from where is the ARP sent?
On Fri, Mar 11, 2011 at 11:48 PM, Virajith Jalaparti
<virajith.j@gmail.com> wrote:
> Hi,
>
> I was hoping someone could help me out with a question I had about the live
> migration of Xen.
> I am trying to perform live migration of a VM using Xen 3.4.3. When
> paravirtualization is used, a gratuitous arp is sent out after the VM is
> restored at the new location (I did not find such an arp being sent when the
> VM is fully virtualized). Is this arp sent out by xen (the hypervisor) or
> the modified operating system? If the arp is sent by xen, which part of the
> xen code (which file?) actually sends out this arp? If the arp is not sent
> by xen, is it possible to send an arp from xen rather than the OS? I think
> we would require to know the IP address and the MAC address of the VM for
> this purpose.
>

Maybe a search through the code would be helpful:
http://lxr.xensource.com/lxr/search?string=arp


Thanks,
Todd

> Thanks,
> Virajith
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>



--
Todd Deshane
http://www.linkedin.com/in/deshantm
http://www.xen.org/products/cloudxen.html

_______________________________________________
Xen-research mailing list
Xen-research@lists.xensource.com
http://lists.xensource.com/mailman/listinfo/xen-research
Re: [Xen-users] Xen live migration: from where is the ARP sent? [ In reply to ]
On Sat, Mar 12, 2011 at 03:37:12PM +0000, Todd Deshane wrote:
> On Fri, Mar 11, 2011 at 11:48 PM, Virajith Jalaparti
> <virajith.j@gmail.com> wrote:
> > Hi,
> >
> > I was hoping someone could help me out with a question I had about the live
> > migration of Xen.
> > I am trying to perform live migration of a VM using Xen 3.4.3. When
> > paravirtualization is used, a gratuitous arp is sent out after the VM is
> > restored at the new location (I did not find such an arp being sent when the
> > VM is fully virtualized). Is this arp sent out by xen (the hypervisor) or
> > the modified operating system? If the arp is sent by xen, which part of the
> > xen code (which file?) actually sends out this arp? If the arp is not sent
> > by xen, is it possible to send an arp from xen rather than the OS? I think
> > we would require to know the IP address and the MAC address of the VM for
> > this purpose.
> >
>
> Maybe a search through the code would be helpful:
> http://lxr.xensource.com/lxr/search?string=arp
>

Hello,

I just asked Ian Campbell about this, and it's always the guest VM kernel
that has the responsibility to send the gratuitous arp packet.

Upstream (kernel.org) pvops kernels got this feature enabled just some months ago,
but nowadays it's also enabled in the longterm 2.6.32.xy releases.

-- Pasi

>
> Thanks,
> Todd
>
> > Thanks,
> > Virajith
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@lists.xensource.com
> > http://lists.xensource.com/xen-users
> >
>
>
>
> --
> Todd Deshane
> http://www.linkedin.com/in/deshantm
> http://www.xen.org/products/cloudxen.html
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users

_______________________________________________
Xen-research mailing list
Xen-research@lists.xensource.com
http://lists.xensource.com/mailman/listinfo/xen-research