Documentation/faq/releases.rst

   1 ..
   2       Licensed under the Apache License, Version 2.0 (the "License"); you may
   3       not use this file except in compliance with the License. You may obtain
   4       a copy of the License at
   5
   6           http://www.apache.org/licenses/LICENSE-2.0
   7
   8       Unless required by applicable law or agreed to in writing, software
   9       distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  10       WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  11       License for the specific language governing permissions and limitations
  12       under the License.
  13
  14       Convention for heading levels in Open vSwitch documentation:
  15
  16       =======  Heading 0 (reserved for the title in a document)
  17       -------  Heading 1
  18       ~~~~~~~  Heading 2
  19       +++++++  Heading 3
  20       '''''''  Heading 4
  21
  22       Avoid deeper levels because they do not render well.
  23
  24 ========
  25 Releases
  26 ========
  27
  28 Q: What does it mean for an Open vSwitch release to be LTS (long-term support)?
  29
  30     A: All official releases have been through a comprehensive testing process
  31     and are suitable for production use.  Planned releases occur twice a year.
  32     If a significant bug is identified in an LTS release, we will provide an
  33     updated release that includes the fix.  Releases that are not LTS may not
  34     be fixed and may just be supplanted by the next major release.  The current
  35     LTS release is 2.5.x.
  36
  37     For more information on the Open vSwitch release process, refer to
  38     :doc:`/internals/release-process`.
  39
  40 Q: What Linux kernel versions does each Open vSwitch release work with?
  41
  42     A: The following table lists the Linux kernel versions against which the
  43     given versions of the Open vSwitch kernel module will successfully build.
  44     The Linux kernel versions are upstream kernel versions, so Linux kernels
  45     modified from the upstream sources may not build in some cases even if they
  46     are based on a supported version.  This is most notably true of Red Hat
  47     Enterprise Linux (RHEL) kernels, which are extensively modified from
  48     upstream.
  49
  50     ============ ==============
  51     Open vSwitch Linux kernel
  52     ============ ==============
  53     1.4.x        2.6.18 to 3.2
  54     1.5.x        2.6.18 to 3.2
  55     1.6.x        2.6.18 to 3.2
  56     1.7.x        2.6.18 to 3.3
  57     1.8.x        2.6.18 to 3.4
  58     1.9.x        2.6.18 to 3.8
  59     1.10.x       2.6.18 to 3.8
  60     1.11.x       2.6.18 to 3.8
  61     2.0.x        2.6.32 to 3.10
  62     2.1.x        2.6.32 to 3.11
  63     2.3.x        2.6.32 to 3.14
  64     2.4.x        2.6.32 to 4.0
  65     2.5.x        2.6.32 to 4.3
  66     2.6.x        3.10 to 4.7
  67     2.7.x        3.10 to 4.9
  68     2.8.x        3.10 to 4.12
  69     2.9.x        3.10 to 4.13
  70     2.10.x       3.10 to 4.17
  71     2.11.x       3.10 to 4.18
  72     2.12.x       3.10 to 5.0
  73     ============ ==============
  74
  75     Open vSwitch userspace should also work with the Linux kernel module built
  76     into Linux 3.3 and later.
  77
  78     Open vSwitch userspace is not sensitive to the Linux kernel version.  It
  79     should build against almost any kernel, certainly against 2.6.32 and later.
  80
  81 Q: Are all features available with all datapaths?
  82
  83     A: Open vSwitch supports different datapaths on different platforms.  Each
  84     datapath has a different feature set: the following tables try to summarize
  85     the status.
  86
  87     Supported datapaths:
  88
  89     Linux upstream
  90       The datapath implemented by the kernel module shipped with Linux
  91       upstream.  Since features have been gradually introduced into the kernel,
  92       the table mentions the first Linux release whose OVS module supports the
  93       feature.
  94
  95     Linux OVS tree
  96       The datapath implemented by the Linux kernel module distributed with the
  97       OVS source tree.
  98
  99     Userspace
 100       This datapath supports conventional system devices as well as
 101       DPDK and AF_XDP devices when support for those is built.  This
 102       is the only datapath that works on NetBSD, FreeBSD and Mac OSX.
 103
 104     Hyper-V
 105       Also known as the Windows datapath.
 106
 107     The following table lists the datapath supported features from an
 108     Open vSwitch user's perspective.  The "Linux upstream" column
 109     lists the Linux kernel version that introduced a given feature
 110     into its kernel module.  The "Linux OVS tree" and "Userspace"
 111     columns list the Open vSwitch release versions that introduced a
 112     given feature into the included kernel module or the userspace
 113     datapath, respectively.
 114
 115     ========================== ============== ============== ========= =======
 116     Feature                    Linux upstream Linux OVS tree Userspace Hyper-V
 117     ========================== ============== ============== ========= =======
 118     Connection tracking             4.3            2.5          2.6      YES
 119     Conntrack Fragment Reass.       4.3            2.6          2.10     YES
 120     Conntrack Timeout Policies      5.2            2.12         NO       NO
 121     Conntrack Zone Limit            4.18           2.10         NO       YES
 122     Conntrack NAT                   4.6            2.6          2.8      YES
 123     Tunnel - LISP                   NO             2.11         NO       NO
 124     Tunnel - STT                    NO             2.4          NO       YES
 125     Tunnel - GRE                    3.11           1.0          2.4      YES
 126     Tunnel - VXLAN                  3.12           1.10         2.4      YES
 127     Tunnel - Geneve                 3.18           2.4          2.4      YES
 128     Tunnel - GRE-IPv6               4.18           2.6          2.6      NO
 129     Tunnel - VXLAN-IPv6             4.3            2.6          2.6      NO
 130     Tunnel - Geneve-IPv6            4.4            2.6          2.6      NO
 131     Tunnel - ERSPAN                 4.18           2.10         2.10     NO
 132     Tunnel - ERSPAN-IPv6            4.18           2.10         2.10     NO
 133     QoS - Policing                  YES            1.1          2.6      NO
 134     QoS - Shaping                   YES            1.1          NO       NO
 135     sFlow                           YES            1.0          1.0      NO
 136     IPFIX                           3.10           1.11         1.11     YES
 137     Set action                      YES            1.0          1.0    PARTIAL
 138     NIC Bonding                     YES            1.0          1.0      YES
 139     Multiple VTEPs                  YES            1.10         1.10     YES
 140     Meter action                    4.15           2.10         2.7      NO
 141     ========================== ============== ============== ========= =======
 142
 143     Do note, however:
 144
 145     * Only a limited set of flow fields is modifiable via the set action by the
 146       Hyper-V datapath.
 147
 148     * Userspace datapath support, in some cases, is dependent on the associated
 149       interface types.  For example, DPDK interfaces support ingress and egress
 150       policing, but not shaping.
 151
 152     The following table lists features that do not *directly* impact an Open
 153     vSwitch user, e.g. because their absence can be hidden by the ofproto layer
 154     (usually this comes with a performance penalty).
 155
 156     ===================== ============== ============== ========= =======
 157     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 158     ===================== ============== ============== ========= =======
 159     SCTP flows            3.12           YES            YES       YES
 160     MPLS                  3.19           YES            YES       YES
 161     UFID                  4.0            YES            YES       NO
 162     Megaflows             3.12           YES            YES       NO
 163     Masked set action     4.0            YES            YES       NO
 164     Recirculation         3.19           YES            YES       YES
 165     TCP flags matching    3.13           YES            YES       NO
 166     Validate flow actions YES            YES            N/A       NO
 167     Multiple datapaths    YES            YES            YES       NO
 168     Tunnel TSO - STT      N/A            YES            NO        YES
 169     ===================== ============== ============== ========= =======
 170
 171 Q: What DPDK version does each Open vSwitch release work with?
 172
 173     A: The following table lists the DPDK version against which the given
 174     versions of Open vSwitch will successfully build.
 175
 176     ============ =======
 177     Open vSwitch DPDK
 178     ============ =======
 179     2.2.x        1.6
 180     2.3.x        1.6
 181     2.4.x        2.0
 182     2.5.x        2.2
 183     2.6.x        16.07.2
 184     2.7.x        16.11.9
 185     2.8.x        17.05.2
 186     2.9.x        17.11.4
 187     2.10.x       17.11.4
 188     2.11.x       18.11.2
 189     2.12.x       18.11.2
 190     ============ =======
 191
 192 Q: Are all the DPDK releases that OVS versions work with maintained?
 193
 194     No. DPDK follows YY.MM.n (Year.Month.Number) versioning.
 195
 196     Typically, all DPDK releases get a stable YY.MM.1 update with bugfixes 3
 197     months after the YY.MM.0 release. In some cases there may also be a
 198     YY.MM.2 release.
 199
 200     DPDK LTS releases start once a year at YY.11.0 and are maintained for
 201     two years, with YY.MM.n+1 releases around every 3 months.
 202
 203     The latest information about DPDK stable and LTS releases can be found
 204     at `DPDK stable`_.
 205
 206 .. _DPDK stable: http://dpdk.org/doc/guides/contributing/stable.html
 207
 208 Q: I get an error like this when I configure Open vSwitch:
 209
 210         configure: error: Linux kernel in <dir> is version <x>, but
 211         version newer than <y> is not supported (please refer to the
 212         FAQ for advice)
 213
 214     What should I do?
 215
 216     A: You have the following options:
 217
 218     - Use the Linux kernel module supplied with the kernel that you are using.
 219       (See also the following FAQ.)
 220
 221     - If there is a newer released version of Open vSwitch, consider building
 222       that one, because it may support the kernel that you are building
 223       against.  (To find out, consult the table in the previous FAQ.)
 224
 225     - The Open vSwitch "master" branch may support the kernel that you are
 226       using, so consider building the kernel module from "master".
 227
 228     All versions of Open vSwitch userspace are compatible with all versions of
 229     the Open vSwitch kernel module, so you do not have to use the kernel module
 230     from one source along with the userspace programs from the same source.
 231
 232 Q: What features are not available in the Open vSwitch kernel datapath that
 233 ships as part of the upstream Linux kernel?
 234
 235     A: The kernel module in upstream Linux does not include support for LISP.
 236     Work is in progress to add support for LISP to the upstream Linux version
 237     of the Open vSwitch kernel module. For now, if you need this feature, use
 238     the kernel module from the Open vSwitch distribution instead of the
 239     upstream Linux kernel module.
 240
 241     Certain features require kernel support to function or to have reasonable
 242     performance. If the ovs-vswitchd log file indicates that a feature is not
 243     supported, consider upgrading to a newer upstream Linux release or using
 244     the kernel module paired with the userspace distribution.
 245
 246 Q: Why do tunnels not work when using a kernel module other than the one
 247 packaged with Open vSwitch?
 248
 249     A: Support for tunnels was added to the upstream Linux kernel module after
 250     the rest of Open vSwitch. As a result, some kernels may contain support for
 251     Open vSwitch but not tunnels. The minimum kernel version that supports each
 252     tunnel protocol is:
 253
 254     ======== ============
 255     Protocol Linux Kernel
 256     ======== ============
 257     GRE      3.11
 258     VXLAN    3.12
 259     Geneve   3.18
 260     ERSPAN   4.18
 261     LISP     not upstream
 262     STT      not upstream
 263     ======== ============
 264
 265     If you are using a version of the kernel that is older than the one listed
 266     above, it is still possible to use that tunnel protocol. However, you must
 267     compile and install the kernel module included with the Open vSwitch
 268     distribution rather than the one on your machine. If problems persist after
 269     doing this, check to make sure that the module that is loaded is the one
 270     you expect.
 271
 272 Q: Why are UDP tunnel checksums not computed for VXLAN or Geneve?
 273
 274     A: Generating outer UDP checksums requires kernel support that was not part
 275     of the initial implementation of these protocols. If using the upstream
 276     Linux Open vSwitch module, you must use kernel 4.0 or newer. The
 277     out-of-tree modules from Open vSwitch release 2.4 and later support UDP
 278     checksums.
 279
 280 Q: What features are not available when using the userspace datapath?
 281
 282     A: Tunnel virtual ports are not supported, as described in the previous
 283     answer.  It is also not possible to use queue-related actions.  On Linux
 284     kernels before 2.6.39, maximum-sized VLAN packets may not be transmitted.
 285
 286 Q: Should userspace or kernel be upgraded first to minimize downtime?
 287
 288     A. In general, the Open vSwitch userspace should be used with the kernel
 289     version included in the same release or with the version from upstream
 290     Linux.  However, when upgrading between two releases of Open vSwitch it is
 291     best to migrate userspace first to reduce the possibility of
 292     incompatibilities.
 293
 294 Q: What happened to the bridge compatibility feature?
 295
 296     A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.
 297     When it was enabled, Open vSwitch imitated the interface of the Linux
 298     kernel "bridge" module.  This allowed users to drop Open vSwitch into
 299     environments designed to use the Linux kernel bridge module without
 300     adapting the environment to use Open vSwitch.
 301
 302     Open vSwitch 1.10 and later do not support bridge compatibility.  The
 303     feature was dropped because version 1.10 adopted a new internal
 304     architecture that made bridge compatibility difficult to maintain.  Now
 305     that many environments use OVS directly, it would be rarely useful in any
 306     case.
 307
 308     To use bridge compatibility, install OVS 1.9 or earlier, including the
 309     accompanying kernel modules (both the main and bridge compatibility
 310     modules), following the instructions that come with the release.  Be sure
 311     to start the ovs-brcompatd daemon.