1 How to Install Open vSwitch on Linux, FreeBSD and NetBSD
2 ========================================================
4 This document describes how to build and install Open vSwitch on a
5 generic Linux, FreeBSD, or NetBSD host. For specifics around installation
6 on a specific platform, please see one of these files:
16 To compile the userspace programs in the Open vSwitch distribution,
17 you will need the following software:
21 - A C compiler, such as:
25 * Clang. Clang 3.4 and later provide useful static semantic
26 analysis and thread-safety checks. For Ubuntu, there are
27 nightly built packages available on clang's website.
29 - libssl, from OpenSSL, is optional but recommended if you plan to
30 connect the Open vSwitch to an OpenFlow controller. libssl is
31 required to establish confidentiality and authenticity in the
32 connections from an Open vSwitch to an OpenFlow controller. If
33 libssl is installed, then Open vSwitch will automatically build
36 To compile the kernel module on Linux, you must also install the
37 following. If you cannot build or install the kernel module, you may
38 use the userspace-only implementation, at a cost in performance. The
39 userspace implementation may also lack some features. Refer to
40 INSTALL.userspace for more information.
42 - A supported Linux kernel version. Please refer to README for a
43 list of supported versions.
45 The Open vSwitch datapath requires bridging support
46 (CONFIG_BRIDGE) to be built as a kernel module. (This is common
47 in kernels provided by Linux distributions.) The bridge module
48 must not be loaded or in use. If the bridge module is running
49 (check with "lsmod | grep bridge"), you must remove it ("rmmod
50 bridge") before starting the datapath.
52 For optional support of ingress policing, you must enable kernel
53 configuration options NET_CLS_BASIC, NET_SCH_INGRESS, and
54 NET_ACT_POLICE, either built-in or as modules. (NET_CLS_POLICE is
55 obsolete and not needed.)
57 To use GRE tunneling on Linux 2.6.37 or newer, kernel support
58 for GRE must be compiled in or available as a module
59 (CONFIG_NET_IPGRE_DEMUX).
61 To configure HTB or HFSC quality of service with Open vSwitch,
62 you must enable the respective configuration options.
64 To use Open vSwitch support for TAP devices, you must enable
67 - To build a kernel module, you need the same version of GCC that
68 was used to build that kernel.
70 - A kernel build directory corresponding to the Linux kernel image
71 the module is to run on. Under Debian and Ubuntu, for example,
72 each linux-image package containing a kernel binary has a
73 corresponding linux-headers package with the required build
76 If you are working from a Git tree or snapshot (instead of from a
77 distribution tarball), or if you modify the Open vSwitch build system
78 or the database schema, you will also need the following software:
80 - Autoconf version 2.64 or later.
82 - Automake version 1.10 or later.
84 - Python 2.x, for x >= 4.
86 If you modify the ovsdbmonitor tool, then you will also need the
89 - pyuic4 from PyQt4 (http://www.riverbankcomputing.co.uk).
91 To run the unit tests, you also need:
93 - Perl. Version 5.10.1 is known to work. Earlier versions should
96 The ovs-vswitchd.conf.db(5) manpage will include an E-R diagram, in
97 formats other than plain text, only if you have the following:
99 - "dot" from graphviz (http://www.graphviz.org/).
101 - Perl. Version 5.10.1 is known to work. Earlier versions should
104 - Python 2.x, for x >= 4.
106 If you are going to extensively modify Open vSwitch, please consider
107 installing the following to obtain better warnings:
109 - "sparse" version 0.4.4 or later
110 (http://www.kernel.org/pub/software/devel/sparse/dist/).
114 - clang, version 3.4 or later
116 Also, you may find the ovs-dev script found in utilities/ovs-dev.py useful.
118 Installation Requirements
119 -------------------------
121 The machine on which Open vSwitch is to be installed must have the
124 - libc compatible with the libc used for build.
126 - libssl compatible with the libssl used for build, if OpenSSL was
129 - On Linux, the same kernel version configured as part of the build.
131 - For optional support of ingress policing on Linux, the "tc" program
132 from iproute2 (part of all major distributions and available at
133 http://www.linux-foundation.org/en/Net:Iproute2).
135 On Linux you should ensure that /dev/urandom exists. To support TAP
136 devices, you must also ensure that /dev/net/tun exists.
138 To run the ovsdbmonitor tool, the machine must also have the following
141 - Python 2.x, for x >= 4.
143 - Python Twisted Conch.
149 - Python Zope interface module.
151 (On Debian "lenny" the above can be installed with "apt-get install
152 python-json python-qt4 python-zopeinterface python-twisted-conch".)
154 Building and Installing Open vSwitch for Linux, FreeBSD or NetBSD
155 =================================================================
157 Once you have installed all the prerequisites listed above in the Base
158 Prerequisites section, follow the procedure below to build.
160 1. If you pulled the sources directly from an Open vSwitch Git tree,
161 run boot.sh in the top source directory:
165 2. In the top source directory, configure the package by running the
166 configure script. You can usually invoke configure without any
171 By default all files are installed under /usr/local. If you want
172 to install into, e.g., /usr and /var instead of /usr/local and
173 /usr/local/var, add options as shown here:
175 % ./configure --prefix=/usr --localstatedir=/var
177 To use a specific C compiler for compiling Open vSwitch user
178 programs, also specify it on the configure command line, like so:
180 % ./configure CC=gcc-4.2
182 To use 'clang' compiler:
184 % ./configure CC=clang
186 To build the Linux kernel module, so that you can run the
187 kernel-based switch, pass the location of the kernel build
188 directory on --with-linux. For example, to build for a running
191 % ./configure --with-linux=/lib/modules/`uname -r`/build
193 If you wish to build the kernel module for an architecture other
194 than the architecture of the machine used for the build, you may
195 specify the kernel architecture string using the KARCH variable
196 when invoking the configure script. For example, to build for MIPS
199 % ./configure --with-linux=/path/to/linux KARCH=mips
201 If you plan to do much Open vSwitch development, you might want to
202 add --enable-Werror, which adds the -Werror option to the compiler
203 command line, turning warnings into errors. That makes it
204 impossible to miss warnings generated by the build.
206 The configure script accepts a number of other options and honors
207 additional environment variables. For a full list, invoke
208 configure with the --help option.
210 3. Run GNU make in the top source directory, e.g.:
214 or if GNU make is installed as "gmake":
218 For improved warnings if you installed "sparse" (see
219 "Prerequisites"), add C=1 to the command line.
221 4. Consider running the testsuite. Refer to "Running the Testsuite"
222 below, for instructions.
224 5. Become root by running "su" or another program.
226 6. Run "make install" to install the executables and manpages into the
227 running system, by default under /usr/local.
229 7. If you built kernel modules, you may install and load them, e.g.:
231 % make modules_install
232 % /sbin/modprobe openvswitch
234 To verify that the modules have been loaded, run "/sbin/lsmod" and
235 check that openvswitch is listed.
237 If the "modprobe" operation fails, look at the last few kernel log
238 messages (e.g. with "dmesg | tail"):
240 - The message "openvswitch: exports duplicate symbol
241 br_should_route_hook (owned by bridge)" means that the bridge
242 module is loaded. Run "/sbin/rmmod bridge" to remove it.
244 If "/sbin/rmmod bridge" fails with "ERROR: Module bridge does
245 not exist in /proc/modules", then the bridge is compiled into
246 the kernel, rather than as a module. Open vSwitch does not
247 support this configuration (see "Build Requirements", above).
249 - The message "openvswitch: exports duplicate symbol
250 dp_ioctl_hook (owned by ofdatapath)" means that the ofdatapath
251 module from the OpenFlow reference implementation is loaded.
252 Run "/sbin/rmmod ofdatapath" to remove it. (You might have to
253 delete any existing datapaths beforehand, using the "dpctl"
254 program included with the OpenFlow reference implementation.
255 "ovs-dpctl" will not work.)
257 - Otherwise, the most likely problem is that Open vSwitch was
258 built for a kernel different from the one into which you are
259 trying to load it. Run "modinfo" on openvswitch.ko and on
260 a module built for the running kernel, e.g.:
262 % /sbin/modinfo openvswitch.ko
263 % /sbin/modinfo /lib/modules/`uname -r`/kernel/net/bridge/bridge.ko
265 Compare the "vermagic" lines output by the two commands. If
266 they differ, then Open vSwitch was built for the wrong kernel.
268 - If you decide to report a bug or ask a question related to
269 module loading, please include the output from the "dmesg" and
270 "modinfo" commands mentioned above.
272 There is an optional module parameter to openvswitch.ko called
273 vlan_tso that enables TCP segmentation offload over VLANs on NICs
274 that support it. Many drivers do not expose support for TSO on VLANs
275 in a way that Open vSwitch can use but there is no way to detect
276 whether this is the case. If you know that your particular driver can
277 handle it (for example by testing sending large TCP packets over VLANs)
278 then passing in a value of 1 may improve performance. Modules built for
279 Linux kernels 2.6.37 and later, as well as specially patched versions
280 of earlier kernels, do not need this and do not have this parameter. If
281 you do not understand what this means or do not know if your driver
282 will work, do not set this.
284 8. Initialize the configuration database using ovsdb-tool, e.g.:
286 % mkdir -p /usr/local/etc/openvswitch
287 % ovsdb-tool create /usr/local/etc/openvswitch/conf.db vswitchd/vswitch.ovsschema
292 Before starting ovs-vswitchd itself, you need to start its
293 configuration database, ovsdb-server. Each machine on which Open
294 vSwitch is installed should run its own copy of ovsdb-server.
295 Configure it to use the database you created during step 7 of
296 installation, above, to listen on a Unix domain socket, to connect to
297 any managers specified in the database itself, and to use the SSL
298 configuration in the database:
300 % ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock \
301 --remote=db:Open_vSwitch,Open_vSwitch,manager_options \
302 --private-key=db:Open_vSwitch,SSL,private_key \
303 --certificate=db:Open_vSwitch,SSL,certificate \
304 --bootstrap-ca-cert=db:Open_vSwitch,SSL,ca_cert \
307 (If you built Open vSwitch without SSL support, then omit
308 --private-key, --certificate, and --bootstrap-ca-cert.)
310 Then initialize the database using ovs-vsctl. This is only
311 necessary the first time after you create the database with
312 ovsdb-tool (but running it at any time is harmless):
314 % ovs-vsctl --no-wait init
316 Then start the main Open vSwitch daemon, telling it to connect to the
317 same Unix domain socket:
319 % ovs-vswitchd --pidfile --detach
321 Now you may use ovs-vsctl to set up bridges and other Open vSwitch
322 features. For example, to create a bridge named br0 and add ports
323 eth0 and vif1.0 to it:
325 % ovs-vsctl add-br br0
326 % ovs-vsctl add-port br0 eth0
327 % ovs-vsctl add-port br0 vif1.0
329 Please refer to ovs-vsctl(8) for more details.
334 When you upgrade Open vSwitch from one version to another, you should
335 also upgrade the database schema:
337 1. Stop the Open vSwitch daemons, e.g.:
339 % kill `cd /usr/local/var/run/openvswitch && cat ovsdb-server.pid ovs-vswitchd.pid`
341 2. Install the new Open vSwitch release.
343 3. Upgrade the database, in one of the following two ways:
345 - If there is no important data in your database, then you may
346 delete the database file and recreate it with ovsdb-tool,
347 following the instructions under "Building and Installing Open
348 vSwitch for Linux, FreeBSD or NetBSD".
350 - If you want to preserve the contents of your database, back it
351 up first, then use "ovsdb-tool convert" to upgrade it, e.g.:
353 % ovsdb-tool convert /usr/local/etc/openvswitch/conf.db vswitchd/vswitch.ovsschema
355 4. Start the Open vSwitch daemons as described under "Building and
356 Installing Open vSwitch for Linux, FreeBSD or NetBSD" above.
360 Upgrading Open vSwitch from one version to the next version with minimum
361 disruption of traffic going through the system that is using that Open vSwitch
362 needs some considerations:
364 1. If the upgrade only involves upgrading the userspace utilities and daemons
365 of Open vSwitch, make sure that the new userspace version is compatible with
366 the previously loaded kernel module.
368 2. An upgrade of userspace daemons means that they have to be restarted.
369 Restarting the daemons means that the Openflow flows in the ovs-vswitchd daemon
370 will be lost. One way to restore the flows is to let the controller
371 re-populate it. Another way is to save the previous flows using a utility
372 like ovs-ofctl and then re-add them after the restart. Restoring the old flows
373 is accurate only if the new Open vSwitch interfaces retain the old 'ofport'
376 3. When the new userspace daemons get restarted, they automatically flush
377 the old flows setup in the kernel. This can be expensive if there are hundreds
378 of new flows that are entering the kernel but userspace daemons are busy
379 setting up new userspace flows from either the controller or an utility like
380 ovs-ofctl. Open vSwitch database provides an option to solve this problem
381 through the other_config:flow-restore-wait column of the Open_vSwitch table.
382 Refer to the ovs-vswitchd.conf.db(5) manpage for details.
384 4. If the upgrade also involves upgrading the kernel module, the old kernel
385 module needs to be unloaded and the new kernel module should be loaded. This
386 means that the kernel network devices belonging to Open vSwitch is recreated
387 and the kernel flows are lost. The downtime of the traffic can be reduced
388 if the userspace daemons are restarted immediately and the userspace flows
389 are restored as soon as possible.
391 The ovs-ctl utility's "restart" function only restarts the userspace daemons,
392 makes sure that the 'ofport' values remain consistent across restarts, restores
393 userspace flows using the ovs-ofctl utility and also uses the
394 other_config:flow-restore-wait column to keep the traffic downtime to the
395 minimum. The ovs-ctl utility's "force-reload-kmod" function does all of the
396 above, but also replaces the old kernel module with the new one. Open vSwitch
397 startup scripts for Debian, XenServer and RHEL use ovs-ctl's functions and it
398 is recommended that these functions be used for other software platforms too.
400 Running the Testsuite
401 =====================
403 Open vSwitch includes a testsuite. Before you submit patches
404 upstream, we advise that you run the tests and ensure that they pass.
405 If you add new features to Open vSwitch, then adding tests for those
406 features will ensure your features don't break as developers modify
407 other areas of Open vSwitch.
409 You must configure and build Open vSwitch (steps 1 through 3 in
410 "Building and Installing Open vSwitch for Linux, FreeBSD or NetBSD" above)
411 before you run the testsuite. You do not need to install Open vSwitch
412 or to build or load the kernel module to run the testsuite. You do
413 not need supervisor privilege to run the testsuite.
415 To run all the unit tests in Open vSwitch, one at a time:
417 This takes under 5 minutes on a modern desktop system.
419 To run all the unit tests in Open vSwitch, up to 8 in parallel:
420 make check TESTSUITEFLAGS=-j8
421 This takes under a minute on a modern 4-core desktop system.
423 To see a list of all the available tests, run:
424 make check TESTSUITEFLAGS=--list
426 To run only a subset of tests, e.g. test 123 and tests 477 through 484:
427 make check TESTSUITEFLAGS='123 477-484'
428 (Tests do not have inter-dependencies, so you may run any subset.)
430 To run tests matching a keyword, e.g. "ovsdb":
431 make check TESTSUITEFLAGS='-k ovsdb'
433 To see a complete list of test options:
434 make check TESTSUITEFLAGS=--help
436 The results of a testing run are reported in tests/testsuite.log.
437 Please report test failures as bugs and include the testsuite.log in
440 If you have "valgrind" installed, then you can also run the testsuite
441 under valgrind by using "make check-valgrind" in place of "make
442 check". All the same options are available via TESTSUITEFLAGS. When
443 you do this, the "valgrind" results for test <N> are reported in files
444 named tests/testsuite.dir/<N>/valgrind.*. You may find that the
445 valgrind results are easier to interpret if you put "-q" in
446 ~/.valgrindrc, since that reduces the amount of output.
448 Sometimes a few tests may fail on some runs but not others. This is
449 usually a bug in the testsuite, not a bug in Open vSwitch itself. If
450 you find that a test fails intermittently, please report it, since the
451 developers may not have noticed.
456 Please report problems to bugs@openvswitch.org.