VM NIC changes on host move

[Sean Lair <sl...@ippathways.com>]

Hi all,

We are seeing a strange behavior and are still troubleshooting... but what seems to be happening is when we shutdown a VM, and then power it on, on a different host, the VM’s operating systems sees a new NIC and the old NIC is gone.  We aren’t 100% sure this is the scenario yet to reproduce... but the below issue has happened multiple times now on different VMs and the latest time we did purposely power it back up on a different host.

The VMs have been Windows Servers and in device manager the new NIC shows up as NIC #2 and the original NIC is no longer present (it is greyed out indicating it isn’t present).  NIC2 then of course doesn’t have NIC1’s static IP so it causes all kinds of issues...  Any ideas?

CloudStack 4.11.3
CentOS7 / KVM
RedHat VirtIO

[cid:7F130E37-0C79-4BC3-9116-17D644843909-L0-001]

Thanks
Sean

Re: VM NIC changes on host move

[Andrija Panic <an...@gmail.com>]

Hi Sean,

Can you try to do virsh dumpxml and observe for any changes (i.e. MAC
address, or slot/IDs, etc) - if the XML is identical (as it should be,
besides the VNC IP/port) - then that sounds really weird.

Also, when you live migrate the VM to another host, then power off/on -
does the problem happen then (during live migration, the XML stays
identical, apart from the VNC IP/port)?

Regards,
Andrija

On Sat, 2 May 2020 at 05:55, Sean Lair <sl...@ippathways.com> wrote:

> Hi all,
>
> We are seeing a strange behavior and are still troubleshooting... but what
> seems to be happening is when we shutdown a VM, and then power it on, on a
> different host, the VM’s operating systems sees a new NIC and the old NIC
> is gone.  We aren’t 100% sure this is the scenario yet to reproduce...
> but the below issue has happened multiple times now on different VMs and
> the latest time we did purposely power it back up on a different host.
>
> The VMs have been Windows Servers and in device manager the new NIC shows
> up as NIC #2 and the original NIC is no longer present (it is greyed out
> indicating it isn’t present).  NIC2 then of course doesn’t have NIC1’s
> static IP so it causes all kinds of issues...  Any ideas?
>
> CloudStack 4.11.3
> CentOS7 / KVM
> RedHat VirtIO
>
>
>
> Thanks
> Sean
>


-- 

Andrija Panić