xen guest domains won't start Error: Device 0 (vif) could not be connected. Could not find bridge, and none was specified

[Todd Deshane]

 xm create guest1.cfg
Using config file "/etc/xen/guest1.cfg".
Error: Device 0 (vif) could not be connected. Could not find bridge, and none was specified

Same error on both para and HVM guests.

/var/log/xen/xend-debug.log:

Link veth0
1000 is missing.
This may be because you have reached the limit of the number of interfaces
that the loopback driver supports. If the loopback driver is a module, you
may raise this limit by passing it as a parameter (nloopbacks=<N>); if the
driver is compiled statically into the kernel, then you may set the parameter
using netloop.nloopbacks=<N> on the domain 0 kernel command line.

/etc/xen/xend-config.sxp:

(xend-relocation-server yes)
(xend-relocation-hosts-allow '^localhost$ ^localhost\\.localdomain$')
(network-script network-bridge)
(vif-script vif-bridge)
(dom0-min-mem 196)
(dom0-cpus 0)
(vnc-listen '127.0.0.1')
(vncpasswd '')

I googled around for awhile looking for similar problems...since most people start pointing at network card drivers etc...

$ lspci | grep net
00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)
00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)

what module should be loaded for this card?
Internet does work fine on this system.

$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:1A:92:97:26:50
          inet addr:128.153.18.74 Bcast:128.153.23.255 Mask:255.255.248.0
          inet6 addr: fe80::21a:92ff:fe97:2650/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:123720 errors:0 dropped:0 overruns:0 frame:0
          TX packets:61126 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:165942454 (158.2 MB) TX bytes:4652255 (4.4 MB)
          Interrupt:21 Base address:0xc000

eth1 Link encap:Ethernet HWaddr 00:1A:92:97:32:4C
          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:1000
          RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
          Interrupt:20 Base address:0xe000

eth1:avah Link encap:Ethernet HWaddr 00:1A:92:97:32:4C
          inet addr:169.254.5.72 Bcast:169.254.255.255 Mask:255.255.0.0
          UP BROADCAST MULTICAST MTU:1500 Metric:1
          Interrupt:20 Base address:0xe000

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:16436 Metric:1
          RX packets:482 errors:0 dropped:0 overruns:0 frame:0
          TX packets:482 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:24100 (23.5 KB) TX bytes:24100 (23.5 KB)

[Todd Deshane (deshantm)]

this instructions get past that problem and get the guest to start:

http://www.nabble.com/Veth0-missing-t3148102.html

so it seems that the problem is with the network-bridge script and/or with the process of creating the bridge with brctl

[bemis (bemis-ubuntu)]

This appears to be wonky/different behaviour from the "ip" command (in some instances it displays the metric in the route print).

If you simply change the network-bridge script (line #62)
-vifnum=${vifnum:-$(ip route list | awk '/^default / { print $NF }' | sed 's/^[^0-9]*//')}
+vifnum=${vifnum:-$(netstat -arn | awk '/^0.0.0.0 / { print $NF }' | sed 's/^[^0-9]*//')}

everything should work as expected.

[Chuck Short (zulcss)]

Ive added this patch, it should be uploaded soonish (as in this weekend)

[bemis (bemis-ubuntu)]

To clarify: this only fixes one of numerous "issues" that could cause this behaviour, and is addressed in XenSource's bugzilla (http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=950). A more appropriate solution may be to rehash the xen-scripts to be more ubuntu specific (at the very least give more useful error output).
I will look into putting together a batch of pre-run tests to optionally add to the xen-scripts and attach to this ticket.

[Todd Deshane (deshantm)]

Is this possibly related to Bug # 199533

https://bugs.launchpad.net/ubuntu/+source/xen-3.2/+bug/199533