[libvirt] Ask for help about libvirt error: can't get physical interface data for kvm.

Feng Dan Liu liufengd at cn.ibm.com
Thu Jul 1 10:04:16 UTC 2010

Hi Laine,

Thank you for your reply, I just want to verify if these libvirt functions 
can be used to get the physical interface information when using kvm 

It's a good news that Red Hat Enterprise Linux will have a port of netcf 
library :) 

(P.S. I used RHEL5.5 and here are the errors which you can't see in the 
last mail:

virsh command error:
$virsh iface-list --all
error: Failed to list active interfaces
error: This function is not supported by the hypervisor:
libvirt api call error:
libvir: error : this function is not supported by the hypervisor: 
org.libvirt.LibvirtException: this function is not supported by the 
hypervisor: virConnectNumOfInterfaces  )

Best Regards,

Fengdan Liu
Tivoli ITCAM Solution, IBM China Software Development Lab, 
Tel:   13811762746 
Email: liufengd at cn.ibm.com
3/F, Haohai Bldg., No.7, 5th Street, Shangdi, 
Haidian District, Beijing 100085, P.R.China

Laine Stump <laine at laine.org> 
Sent by: sendmail <justsendmailnothingelse at gmail.com>
2010-07-01 00:19

Feng Dan Liu/China/IBM at IBMCN
libvir-list at redhat.com, Flo Kandefer <kandefer at us.ibm.com>, Todd Gatts 
<tgatts at us.ibm.com>, Bruce Anderson <andersbc at us.ibm.com>, Jennifer 
Kuvlesky <jkuvlesk at us.ibm.com>
Re: [libvirt] Ask for help about libvirt error: can't get physical 
interface data for kvm.

On 06/30/2010 05:18 AM, Feng Dan Liu wrote: 

I saw both libvirt api and virsh commands support to get the physical 
interfaces data, but it always fail when I using them for KVM hypervisor. 
I was thought that it was due to the old version of libvirt/KVM 
hypervisor, but the error still exist when using the latest libvirt and 
kvm hypervisor. 

So I wonder if the following functions of libvirt haven't been implemented 
for KVM, could you pls help me get the answer about this? Thanks in 


Just to make sure you understand what these functions do - they are used 
to examine and configure the interfaces on the *physical host* that is 
running the hypervisor, not the virtual hosts (guests) running under that 
hypervisor. (One of the main motivations to add this API was to make it 
easier for management software to create bridge devices on the host, for 
use by the guests).

These functions only work on a system that has the netcf library installed 
(regardless of hypervisor). Currently, only Fedora (12 and beyond), and 
Red Hat Enterprise Linux 6 (in beta) have a port of that library, although 
there has been some talk of a Suse port (and also someone was supposedly 
working on a Gentoo port last year, but I never saw anything more about 

netcf information can be found at https://fedorahosted.org/netcf, and 
there is a mailing list at 

Patches to port netcf to other platforms are gratefully accepted. If you 
are running on a platform that doesn't have netcf support and would like 
to take on that task, please send mail to the list and we'll do what we 
can to help.

(P.S. When you send mail to the libvirt list, you should probably try to 
avoid embedded graphics, as you have used to show your error message - 
many people reading the list are using text-only mail readers, and won't 
be able to see the graphical content.)

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20100701/be563f60/attachment-0001.htm>

More information about the libvir-list mailing list