brcompat failed to be loaded

[ZhengPeng Hou]

1 fresh 12.04.1 installation
2 install openvswitch-datapath-dkms and build-essential
3 try to load the module by using modrpobe, got the error
FATAL: Error inserting brcompat_mod (/lib/modules/3.2.0-29-generic/updates/dkms/brcompat_mod.ko): Invalid module format

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: openvswitch-datapath-dkms 1.4.0-1ubuntu1.3
ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24
Uname: Linux 3.2.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Mon Dec 31 16:05:07 2012
InstallationMedia: Ubuntu-Server 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120817.3)
PackageArchitecture: all
SourcePackage: openvswitch
UpgradeStatus: No upgrade log present (probably fresh install)

[ZhengPeng Hou (zhengpeng-hou)]

This issue still happens in raring with latest openvswitch-1.9 upload.
Jan 17 10:55:30 x220 kernel: [ 187.465654] brcompat: Unknown symbol ovs_dp_ioctl_hook (err 0)

[James Page (james-page)]

The brcompat module does work in raring; however you need to make sure that

1) you are using the dkms version of the openvswitch module, not the stock kernel one

You can do this by stopping the openvswitch-* daemons, unloading the openvswitch module and then reloading it to pickup the dkms version

sudo service openvswitch-switch stop
sudo rmmod openvswitch
sudo modprobe openvswitch

Always make sure that you install the DKMS package prior to installing openvswitch-switch itself other wise you may hit this issue.

2) make sure that you don't already have the bridge module loaded

sudo rmmod bridge

After ensuring 1 & 2 are OK then you should be able to load the brcompat module.

BUT - please note this module is deprecated upstream and will disappear - so try to move to using openvswitch

[James Page (james-page)]

Looks like a similar issue you are having on precise:

ubuntu@ovs-testing-precise:~$ lsmod | grep bridge
ubuntu@ovs-testing-precise:~$ sudo modprobe bridge
ubuntu@ovs-testing-precise:~$ lsmod | grep bridge
bridge 90989 0
stp 12976 1 bridge
ubuntu@ovs-testing-precise:~$ sudo modprobe brcompat_mod
FATAL: Error inserting brcompat_mod (/lib/modules/3.2.0-36-generic/updates/dkms/brcompat_mod.ko): Invalid module format
ubuntu@ovs-testing-precise:~$ sudo rmmod bridge
ubuntu@ovs-testing-precise:~$ sudo modprobe brcompat_mod
ubuntu@ovs-testing-precise:~$

bridge module is conflicting with brcompat_mod.