Description of problem:
While creating multiple network interfaces in the guest domain, the following error is coming while starting the Domain.

error: Failed to start domain vm3
error: internal error Failed to create veth device pair: 512

libvirt Domain XML used to define the guest domain is shown below:

<domain type='lxc' id='1'>
  <name>vm3</name>
    <memory>1000000</memory>
      <os>
          <type>exe</type>
          <init>/bin/bash</init>
      </os>
      <vcpu>1</vcpu>
      <clock offset='utc'/>
      <on_poweroff>destroy</on_poweroff>
      <on_reboot>restart</on_reboot>
      <on_crash>destroy</on_crash>
      <devices>
        <emulator>/usr/libexec/libvirt_lxc</emulator>
        <filesystem type='mount'>
          <source dir='/root/lxc/fedora'/>
          <target dir='/'/>
        </filesystem>
        <interface type='bridge'>
          <source bridge='br0'/>
        </interface>
        <interface type='network'>
          <source network='default'/>
          <target dev='vnet7'/>
          <mac address="00:11:22:33:44:55"/>
        </interface>
        <console type='pty' />
      </devices>
</domain>


Version-Release number of selected component (if applicable):
Compiled against library: libvir 0.8.0
Using library: libvir 0.8.0
Using API: LXC 0.8.0
Running hypervisor: LXC 2.6.31

Fedora 12 32bit os.

How reproducible:


Steps to Reproduce:
1.define a domain with the above domain XML.
2.start the Domain.
3.
  
Actual results:
Unable to start the guest domain. Giving following error:

error: Failed to start domain vm3
error: internal error Failed to create veth device pair: 512

Expected results:
Need to start the guest domain, with two interfaces.

Additional info: