setup and configuration about "juju-br0"

[shhan]

hi all,

I meet a trouble about setup and configuration of "juju-br0" on a node 
of private MAAS environment.
I try to bring up a Container over a node, but failed with following 
messages.

The problem is that I could find the configuration file of juju-br0. any 
suggestions and help will be appreciated.

--------------------------
/var/lib/juju/containers/juju-machine-102-lxc-5/container.log:

lxc-start 1431959506.073 ERROR    lxc_conf - 
conf.c:instantiate_veth:2978 - failed to attach 'veth9PAIYX' to the 
bridge 'juju-br0': No such device
       lxc-start 1431959506.075 INFO     lxc_monitor - 
monitor.c:lxc_monitor_sock_name:177 - using monitor sock name 
lxc/ad055575fe28ddd5//var/lib/lxc
       lxc-start 1431959506.105 ERROR    lxc_conf - 
conf.c:lxc_create_network:3261 - failed to create netdev
       lxc-start 1431959506.105 ERROR    lxc_start - 
start.c:lxc_spawn:826 - failed to create the network
--------------------------

The output of "ifconfig " is:
------------------------------
eth0      Link encap:Ethernet  HWaddr 00:25:90:88:bc:66
           inet addr:10.0.0.102  Bcast:10.0.0.255  Mask:255.255.255.0
           inet6 addr: fe80::225:90ff:fe88:bc66/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:265493 errors:0 dropped:0 overruns:0 frame:0
           TX packets:27886 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:24700318 (24.7 MB)  TX bytes:2804363 (2.8 MB)
           Memory:dfb20000-dfb40000

eth2      Link encap:Ethernet  HWaddr 00:25:90:90:04:8d
           inet6 addr: fe80::225:90ff:fe90:48d/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:218455 errors:0 dropped:0 overruns:0 frame:0
           TX packets:15 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:13981120 (13.9 MB)  TX bytes:1306 (1.3 KB)

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           inet6 addr: ::1/128 Scope:Host
           UP LOOPBACK RUNNING  MTU:65536  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:0
           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lxcbr0    Link encap:Ethernet  HWaddr 3a:ef:2b:d5:88:9a
           inet addr:10.0.1.1  Bcast:10.0.1.255  Mask:255.255.255.0
           inet6 addr: fe80::38ef:2bff:fed5:889a/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 B)  TX bytes:648 (648.0 B)

virbr0    Link encap:Ethernet  HWaddr f6:1b:ae:68:53:b6
           inet addr:192.168.122.1  Bcast:192.168.122.255 Mask:255.255.255.0
           UP 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:0
           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)


------------------------------

current cloud environment:
MAAS: 1.7.3
juju-core: 1.23.2
node OS: ubuntu 14.04.2
-------------------------------


Thanks,

best,
shuchu