[libvirt-users] [netcf] Why netcf can not rename a existing physical interface dynamically by itself?

[Jianwei Hu]

Hi All,

I have a usage question about netcf. Why netcf can not rename a existing physical interface dynamically by itself? If you have any other method, please share to me, or can we add support for it in netcf? You can see the following steps for details.

Version:
netcf-0.2.4-1.el6.x86_64
kernel-2.6.32-431.el6.x86_64

1. Select a existing NIC from host, for example eth1.
[root at rhel6 ~]# ncftool list --all
eth0
eth1
lo
[root at rhel6 ~]# ncftool dumpxml eth1
<?xml version="1.0"?>
<interface type="ethernet" name="eth1">
  <start mode="none"/>
  <mac address="00:1B:21:27:4E:CE"/>
  <protocol family="ipv4">
    <dhcp/>
  </protocol>
</interface>

[root at rhel6 ~]# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:1B:21:27:4E:CE  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

[root at rhel6 ~]# ncftool ifup eth1
Interface eth1 successfully brought up

2. Undefine eth1 from host
[root at rhel6 ~]# ncftool ifdown eth1
Interface eth1 successfully brought down
[root at rhel6 ~]# ncftool undefine eth1
eth1 undefined
[root at rhel6 ~]# ncftool list --all
eth0
lo

3. Prepare another xml with same MAC and a new name "jiahu"
[root at rhel6 ~]# cat jiahu.xml 
<interface type="ethernet" name="jiahu">
 <start mode="none"/>
  <mac address="00:1B:21:27:4E:CE"/>
  <protocol family="ipv4">
    <dhcp/>
  </protocol>
</interface>

4. Define the "jiahu", and start it.
[root at rhel6 ~]# ncftool define jiahu.xml 
Defined interface jiahu
[root at rhel6 ~]# ncftool dumpxml jiahu
<?xml version="1.0"?>
<interface type="ethernet" name="jiahu">
  <start mode="none"/>
  <mac address="00:1B:21:27:4E:CE"/>
  <protocol family="ipv4">
    <dhcp/>
  </protocol>
</interface>

[root at rhel6 ~]# ifconfig jiahu
jiahu: error fetching interface information: Device not found
         
[root at rhel6 ~]# cat /etc/sysconfig/network-scripts/ifcfg-jiahu 
DEVICE=jiahu
HWADDR=00:1B:21:27:4E:CE
ONBOOT=no
BOOTPROTO=dhcp
[root at rhel6 ~]# ncftool ifup jiahu
Interface jiahu bring-up failed!
error: failed to execute external program
error: Running 'ifup jiahu' failed with exit code 1: Device jiahu does not seem to be present, delaying initialization.

[root at rhel6 ~]# ll /sys/class/net/
total 0
lrwxrwxrwx. 1 root root 0 May 23 11:32 eth0 -> ../../devices/pci0000:00/0000:00:19.0/net/eth0
lrwxrwxrwx. 1 root root 0 May 23 11:35 eth1 -> ../../devices/pci0000:00/0000:00:1e.0/0000:02:00.0/net/eth1
lrwxrwxrwx. 1 root root 0 May 23 11:32 lo -> ../../devices/virtual/net/lo
lrwxrwxrwx. 1 root root 0 May 23 11:32 virbr0 -> ../../devices/virtual/net/virbr0
lrwxrwxrwx. 1 root root 0 May 23 11:32 virbr0-nic -> ../../devices/virtual/net/virbr0-nic

5. Reboot the host OS, the jiahu interface appeared.
[root at rhel6 ~]# ifconfig jiahu
jiahu     Link encap:Ethernet  HWaddr 00:1B:21:27:4E:CE  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

BR,
Jianwei