1 How to Install Open vSwitch on Linux
2 ====================================
4 This document describes how to build and install Open vSwitch on a
5 generic Linux host. If you want to install Open vSwitch on a Citrix
6 XenServer, see INSTALL.XenServer instead.
8 This version of Open vSwitch may be built manually with "configure"
9 and "make", as described below. You may also build Debian packages by
10 running "dpkg-buildpackage".
15 To compile the userspace programs in the Open vSwitch distribution,
16 you will need the following software:
18 - A make program, e.g. GNU make. BSD make should also work.
20 - The GNU C compiler. We generally test with version 4.1, 4.2, or
23 - pkg-config. We test with version 0.22.
25 - libssl, from OpenSSL, is optional but recommended if you plan to
26 connect the Open vSwitch to an OpenFlow controller. libssl is
27 required to establish confidentiality and authenticity in the
28 connections from an Open vSwitch to an OpenFlow controller. If
29 libssl is installed, then Open vSwitch will automatically build
32 To compile the kernel module, you must also install the following. If
33 you cannot build or install the kernel module, you may use the
34 userspace-only implementation, at a cost in performance. The
35 userspace implementation may also lack some features. Refer to
36 INSTALL.userspace for more information.
38 - A supported Linux kernel version. Please refer to README for a
39 list of supported versions.
41 The Open vSwitch datapath requires bridging support
42 (CONFIG_BRIDGE) to be built as a kernel module. (This is common
43 in kernels provided by Linux distributions.) The bridge module
44 must not be loaded or in use. If the bridge module is running
45 (check with "lsmod | grep bridge"), you must remove it ("rmmod
46 bridge") before starting the datapath.
48 For optional support of ingress policing, you must enable kernel
49 configuration options NET_CLS_ACT, NET_CLS_U32, NET_SCH_INGRESS,
50 and NET_ACT_POLICE, either built-in or as modules.
51 (NET_CLS_POLICE is obsolete and not needed.)
53 If GRE tunneling is being used it is recommended that the kernel
54 be compiled with IPv6 support (CONFIG_IPV6). This allows for
55 special handling (such as path MTU discovery) of IPv6 packets.
57 To use Open vSwitch support for TAP devices, you must enable
60 - To build a kernel module, you need the same version of GCC that
61 was used to build that kernel.
63 - A kernel build directory corresponding to the Linux kernel image
64 the module is to run on. Under Debian and Ubuntu, for example,
65 each linux-image package containing a kernel binary has a
66 corresponding linux-headers package with the required build
69 If you are working from a Git tree or snapshot (instead of from a
70 distribution tarball), or if you modify the Open vSwitch build system,
71 you will also need the following software:
73 - Autoconf version 2.64 or later.
75 - Automake version 1.10 or later.
77 - Python 2.x, for x >= 4.
79 If you modify the ovsdbmonitor tool, then you will also need the
82 - pyuic4 from PyQt4 (http://www.riverbankcomputing.co.uk).
84 If you modify the vswitchd database schema, then the E-R diagram in
85 the ovs-vswitchd.conf.db(5) manpage will be updated properly only if
86 you have the following:
88 - "dot" from graphviz (http://www.graphviz.org/).
90 Installation Requirements
91 -------------------------
93 The machine on which Open vSwitch is to be installed must have the
96 - libc compatible with the libc used for build.
98 - libssl compatible with the libssl used for build, if OpenSSL was
101 - The Linux kernel version configured as part of the build.
103 - For optional support of ingress policing, the "tc" program from
104 iproute2 (part of all major distributions and available at
105 http://www.linux-foundation.org/en/Net:Iproute2).
107 - For debugging purposes, Open vSwitch expects that "tcpdump" is
108 installed as /usr/sbin/tcpdump. If tcpdump is not installed, or
109 if it is installed in a different location, then some Open
110 vSwitch log messages will not be as detailed.
112 You should ensure that /dev/urandom exists. To support TAP devices,
113 you must also ensure that /dev/net/tun exists.
115 To run the ovsdmonitor tool, the machine must also have the following
118 - Python 2.x, for x >= 4.
120 - Python Twisted Conch.
126 - Python Zope interface module.
128 (On Debian "lenny" the above can be installed with "apt-get install
129 python-json python-qt4 python-zopeinterface python-twisted-conch".)
131 Building and Installing Open vSwitch for Linux
132 ==============================================
134 Once you have installed all the prerequisites listed above in the Base
135 Prerequisites section, follow the procedure below to build.
137 1. If you pulled the sources directly from an Open vSwitch Git tree,
138 run boot.sh in the top source directory:
142 2. In the top source directory, configure the package by running the
143 configure script. You can usually invoke configure without any
148 By default all files are installed under /usr/local. If you want
149 to install into, e.g., /usr and /var instead of /usr/local and
150 /usr/local/var, add options as shown here:
152 % ./configure --prefix=/usr --localstatedir=/var
154 To use a specific C compiler for compiling Open vSwitch user
155 programs, also specify it on the configure command line, like so:
157 % ./configure CC=gcc-4.2
159 To build the Linux kernel module, so that you can run the
160 kernel-based switch, pass the location of the kernel build
161 directory on --with-l26. For example, to build for a running
162 instance of Linux 2.6:
164 % ./configure --with-l26=/lib/modules/`uname -r`/build
166 If you wish to build the kernel module for an architecture other
167 than the architecture of the machine used for the build, you may
168 specify the kernel architecture string using the KARCH variable
169 when invoking the configure script. For example, to build for MIPS
172 % ./configure --with-l26=/path/to/linux-2.6 KARCH=mips
174 The configure script accepts a number of other options and honors
175 additional environment variables. For a full list, invoke
176 configure with the --help option.
178 3. Run make in the top source directory:
182 4. Become root by running "su" or another program.
184 5. Run "make install" to install the executables and manpages into the
185 running system, by default under /usr/local.
187 6. If you built kernel modules, you may load them with "insmod", e.g.:
189 % insmod datapath/linux-2.6/openvswitch_mod.ko
191 You may need to specify a full path to insmod, e.g. /sbin/insmod.
192 To verify that the modules have been loaded, run "/sbin/lsmod" and
193 check that openvswitch_mod is listed.
195 If the "insmod" operation fails, look at the last few kernel log
196 messages (e.g. with "dmesg | tail"):
198 - The message "openvswitch_mod: exports duplicate symbol
199 br_should_route_hook (owned by bridge)" means that the bridge
200 module is loaded. Run "/sbin/rmmod bridge" to remove it.
202 If "/sbin/rmmod bridge" fails with "ERROR: Module bridge does
203 not exist in /proc/modules", then the bridge is compiled into
204 the kernel, rather than as a module. Open vSwitch does not
205 support this configuration (see "Build Requirements", above).
207 - The message "openvswitch_mod: exports duplicate symbol
208 dp_ioctl_hook (owned by ofdatapath)" means that the ofdatapath
209 module from the OpenFlow reference implementation is loaded.
210 Run "/sbin/rmmod ofdatapath" to remove it. (You might have to
211 delete any existing datapaths beforehand, using the "dpctl"
212 program included with the OpenFlow reference implementation.
213 "ovs-dpctl" will not work.)
215 - Otherwise, the most likely problem is that Open vSwitch was
216 built for a kernel different from the one into which you are
217 trying to load it. Run "modinfo" on openvswitch_mod.ko and on
218 a module built for the running kernel, e.g.:
220 % /sbin/modinfo openvswitch_mod.ko
221 % /sbin/modinfo /lib/modules/`uname -r`/kernel/net/bridge/bridge.ko
223 Compare the "vermagic" lines output by the two commands. If
224 they differ, then Open vSwitch was built for the wrong kernel.
226 - If you decide to report a bug or ask a question related to
227 module loading, please include the output from the "dmesg" and
228 "modinfo" commands mentioned above.
230 There is an optional module parameter to openvswitch_mod.ko called
231 vlan_tso that enables TCP segmentation offload over VLANs on NICs
232 that support it. Many drivers do not expose support for TSO on VLANs
233 in a way that Open vSwitch can use but there is no way to detect
234 whether this is the case. If you know that your particular driver can
235 handle it (for example by testing sending large TCP packets over VLANs)
236 then passing in a value of 1 may improve performance. Modules built for
237 Linux kernels 2.6.37 and later do not need this and do not have this
238 parameter. If you do not understand what this means or do not know if
239 your driver will work, do not set this.
241 7. Initialize the configuration database using ovsdb-tool, e.g.:
243 % mkdir -p /usr/local/etc/openvswitch
244 % ovsdb-tool create /usr/local/etc/openvswitch/conf.db vswitchd/vswitch.ovsschema
249 Before starting ovs-vswitchd itself, you need to start its
250 configuration database, ovsdb-server. Each machine on which Open
251 vSwitch is installed should run its own copy of ovsdb-server.
252 Configure it to use the database you created during step 7 of
253 installation, above, to listen on a Unix domain socket, to connect to
254 any managers specified in the database itself, and to use the SSL
255 configuration in the database:
257 % ovsdb-server /usr/local/etc/openvswitch/conf.db \
258 --remote=punix:/usr/local/var/run/openvswitch/db.sock \
259 --remote=db:Open_vSwitch,manager_options \
260 --private-key=db:SSL,private_key \
261 --certificate=db:SSL,certificate \
262 --bootstrap-ca-cert=db:SSL,ca_cert \
265 Then initialize the database using ovs-vsctl. This is only
266 necessary the first time after you create the database with
267 ovsdb-tool (but running it at any time is harmless):
269 % ovs-vsctl --no-wait init
271 Then start the main Open vSwitch daemon, telling it to connect to the
272 same Unix domain socket:
274 % ovs-vswitchd unix:/usr/local/var/run/openvswitch/db.sock \
277 Now you may use ovs-vsctl to set up bridges and other Open vSwitch
278 features. For example, to create a bridge named br0 and add ports
279 eth0 and vif1.0 to it:
281 % ovs-vsctl add-br br0
282 % ovs-vsctl add-port br0 eth0
283 % ovs-vsctl add-port br0 vif1.0
285 Please refer to ovs-vsctl(8) for more details.
290 When you upgrade Open vSwitch from one version to another, you should
291 also upgrade the database schema:
293 1. Stop the Open vSwitch daemons, e.g.:
295 % ovs-kill ovsdb-server.pid ovs-vswitchd.pid
297 2. Install the new Open vSwitch release.
299 3. Upgrade the database, in one of the following two ways:
301 - If there is no important data in your database, then you may
302 delete the database file and recreate it with ovsdb-tool,
303 following the instructions under "Building and Installing Open
306 - If you want to preserve the contents of your database, back it
307 up first, then use "ovsdb-tool convert" to upgrade it, e.g.:
309 % ovsdb-tool convert /usr/local/etc/openvswitch/conf.db vswitchd/vswitch.ovsschema
311 4. Start the Open vSwitch daemons as described under "Building and
312 Installing Open vSwitch for Linux" above.
317 Please report problems to bugs@openvswitch.org.