Documentation/faq/releases.rst

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   6           http://www.apache.org/licenses/LICENSE-2.0
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   8       Unless required by applicable law or agreed to in writing, software
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  10       WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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  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     ============ ==============
  73
  74     Open vSwitch userspace should also work with the Linux kernel module built
  75     into Linux 3.3 and later.
  76
  77     Open vSwitch userspace is not sensitive to the Linux kernel version.  It
  78     should build against almost any kernel, certainly against 2.6.32 and later.
  79
  80 Q: Are all features available with all datapaths?
  81
  82     A: Open vSwitch supports different datapaths on different platforms.  Each
  83     datapath has a different feature set: the following tables try to summarize
  84     the status.
  85
  86     Supported datapaths:
  87
  88     Linux upstream
  89       The datapath implemented by the kernel module shipped with Linux
  90       upstream.  Since features have been gradually introduced into the kernel,
  91       the table mentions the first Linux release whose OVS module supports the
  92       feature.
  93
  94     Linux OVS tree
  95       The datapath implemented by the Linux kernel module distributed with the
  96       OVS source tree.
  97
  98     Userspace
  99       Also known as DPDK, dpif-netdev or dummy datapath. It is the only
 100       datapath that works on NetBSD, FreeBSD and Mac OSX.
 101
 102     Hyper-V
 103       Also known as the Windows datapath.
 104
 105     The following table lists the datapath supported features from an Open
 106     vSwitch user's perspective.
 107
 108     ========================== ============== ============== ========= =======
 109     Feature                    Linux upstream Linux OVS tree Userspace Hyper-V
 110     ========================== ============== ============== ========= =======
 111     Connection tracking             4.3            YES          YES      YES
 112     Conntrack Fragment Reass.       4.3            YES          YES      YES
 113     NAT                             4.6            YES          YES      NO
 114     Conntrack zone limit            4.18           YES          NO       NO
 115     Tunnel - LISP                   NO             YES          NO       NO
 116     Tunnel - STT                    NO             YES          NO       YES
 117     Tunnel - GRE                    3.11           YES          YES      YES
 118     Tunnel - VXLAN                  3.12           YES          YES      YES
 119     Tunnel - Geneve                 3.18           YES          YES      YES
 120     Tunnel - GRE-IPv6               NO             NO           YES      NO
 121     Tunnel - VXLAN-IPv6             4.3            YES          YES      NO
 122     Tunnel - Geneve-IPv6            4.4            YES          YES      NO
 123     Tunnel - ERSPAN                 4.18           YES          YES      NO
 124     Tunnel - ERSPAN-IPv6            4.18           YES          YES      NO
 125     QoS - Policing                  YES            YES          YES      NO
 126     QoS - Shaping                   YES            YES          NO       NO
 127     sFlow                           YES            YES          YES      NO
 128     IPFIX                           3.10           YES          YES      NO
 129     Set action                      YES            YES          YES    PARTIAL
 130     NIC Bonding                     YES            YES          YES      YES
 131     Multiple VTEPs                  YES            YES          YES      YES
 132     Meters                          4.15           YES          YES      NO
 133     ========================== ============== ============== ========= =======
 134
 135     Do note, however:
 136
 137     * Only a limited set of flow fields is modifiable via the set action by the
 138       Hyper-V datapath.
 139
 140     * Userspace datapath support, in some cases, is dependent on the associated
 141       interface types.  For example, DPDK interfaces support ingress and egress
 142       policing, but not shaping.
 143
 144     The following table lists features that do not *directly* impact an Open
 145     vSwitch user, e.g. because their absence can be hidden by the ofproto layer
 146     (usually this comes with a performance penalty).
 147
 148     ===================== ============== ============== ========= =======
 149     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 150     ===================== ============== ============== ========= =======
 151     SCTP flows            3.12           YES            YES       YES
 152     MPLS                  3.19           YES            YES       YES
 153     UFID                  4.0            YES            YES       NO
 154     Megaflows             3.12           YES            YES       NO
 155     Masked set action     4.0            YES            YES       NO
 156     Recirculation         3.19           YES            YES       YES
 157     TCP flags matching    3.13           YES            YES       NO
 158     Validate flow actions YES            YES            N/A       NO
 159     Multiple datapaths    YES            YES            YES       NO
 160     Tunnel TSO - STT      N/A            YES            NO        YES
 161     ===================== ============== ============== ========= =======
 162
 163 Q: What DPDK version does each Open vSwitch release work with?
 164
 165     A: The following table lists the DPDK version against which the given
 166     versions of Open vSwitch will successfully build.
 167
 168     ============ =======
 169     Open vSwitch DPDK
 170     ============ =======
 171     2.2.x        1.6
 172     2.3.x        1.6
 173     2.4.x        2.0
 174     2.5.x        2.2
 175     2.6.x        16.07.2
 176     2.7.x        16.11.8
 177     2.8.x        17.05.2
 178     2.9.x        17.11.4
 179     2.10.x       17.11.4
 180     2.11.x       18.11
 181     ============ =======
 182
 183 Q: Are all the DPDK releases that OVS versions work with maintained?
 184
 185     No. DPDK follows YY.MM.n (Year.Month.Number) versioning.
 186
 187     Typically, all DPDK releases get a stable YY.MM.1 update with bugfixes 3
 188     months after the YY.MM.0 release. In some cases there may also be a
 189     YY.MM.2 release.
 190
 191     DPDK LTS releases start once a year at YY.11.0 and are maintained for
 192     two years, with YY.MM.n+1 releases around every 3 months.
 193
 194     The latest information about DPDK stable and LTS releases can be found
 195     at `DPDK stable`_.
 196
 197 .. _DPDK stable: http://dpdk.org/doc/guides/contributing/stable.html
 198
 199 Q: I get an error like this when I configure Open vSwitch:
 200
 201         configure: error: Linux kernel in <dir> is version <x>, but
 202         version newer than <y> is not supported (please refer to the
 203         FAQ for advice)
 204
 205     What should I do?
 206
 207     A: You have the following options:
 208
 209     - Use the Linux kernel module supplied with the kernel that you are using.
 210       (See also the following FAQ.)
 211
 212     - If there is a newer released version of Open vSwitch, consider building
 213       that one, because it may support the kernel that you are building
 214       against.  (To find out, consult the table in the previous FAQ.)
 215
 216     - The Open vSwitch "master" branch may support the kernel that you are
 217       using, so consider building the kernel module from "master".
 218
 219     All versions of Open vSwitch userspace are compatible with all versions of
 220     the Open vSwitch kernel module, so you do not have to use the kernel module
 221     from one source along with the userspace programs from the same source.
 222
 223 Q: What features are not available in the Open vSwitch kernel datapath that
 224 ships as part of the upstream Linux kernel?
 225
 226     A: The kernel module in upstream Linux does not include support for LISP.
 227     Work is in progress to add support for LISP to the upstream Linux version
 228     of the Open vSwitch kernel module. For now, if you need this feature, use
 229     the kernel module from the Open vSwitch distribution instead of the
 230     upstream Linux kernel module.
 231
 232     Certain features require kernel support to function or to have reasonable
 233     performance. If the ovs-vswitchd log file indicates that a feature is not
 234     supported, consider upgrading to a newer upstream Linux release or using
 235     the kernel module paired with the userspace distribution.
 236
 237 Q: Why do tunnels not work when using a kernel module other than the one
 238 packaged with Open vSwitch?
 239
 240     A: Support for tunnels was added to the upstream Linux kernel module after
 241     the rest of Open vSwitch. As a result, some kernels may contain support for
 242     Open vSwitch but not tunnels. The minimum kernel version that supports each
 243     tunnel protocol is:
 244
 245     ======== ============
 246     Protocol Linux Kernel
 247     ======== ============
 248     GRE      3.11
 249     VXLAN    3.12
 250     Geneve   3.18
 251     ERSPAN   4.18
 252     LISP     not upstream
 253     STT      not upstream
 254     ======== ============
 255
 256     If you are using a version of the kernel that is older than the one listed
 257     above, it is still possible to use that tunnel protocol. However, you must
 258     compile and install the kernel module included with the Open vSwitch
 259     distribution rather than the one on your machine. If problems persist after
 260     doing this, check to make sure that the module that is loaded is the one
 261     you expect.
 262
 263 Q: Why are UDP tunnel checksums not computed for VXLAN or Geneve?
 264
 265     A: Generating outer UDP checksums requires kernel support that was not part
 266     of the initial implementation of these protocols. If using the upstream
 267     Linux Open vSwitch module, you must use kernel 4.0 or newer. The
 268     out-of-tree modules from Open vSwitch release 2.4 and later support UDP
 269     checksums.
 270
 271 Q: What features are not available when using the userspace datapath?
 272
 273     A: Tunnel virtual ports are not supported, as described in the previous
 274     answer.  It is also not possible to use queue-related actions.  On Linux
 275     kernels before 2.6.39, maximum-sized VLAN packets may not be transmitted.
 276
 277 Q: Should userspace or kernel be upgraded first to minimize downtime?
 278
 279     A. In general, the Open vSwitch userspace should be used with the kernel
 280     version included in the same release or with the version from upstream
 281     Linux.  However, when upgrading between two releases of Open vSwitch it is
 282     best to migrate userspace first to reduce the possibility of
 283     incompatibilities.
 284
 285 Q: What happened to the bridge compatibility feature?
 286
 287     A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.
 288     When it was enabled, Open vSwitch imitated the interface of the Linux
 289     kernel "bridge" module.  This allowed users to drop Open vSwitch into
 290     environments designed to use the Linux kernel bridge module without
 291     adapting the environment to use Open vSwitch.
 292
 293     Open vSwitch 1.10 and later do not support bridge compatibility.  The
 294     feature was dropped because version 1.10 adopted a new internal
 295     architecture that made bridge compatibility difficult to maintain.  Now
 296     that many environments use OVS directly, it would be rarely useful in any
 297     case.
 298
 299     To use bridge compatibility, install OVS 1.9 or earlier, including the
 300     accompanying kernel modules (both the main and bridge compatibility
 301     modules), following the instructions that come with the release.  Be sure
 302     to start the ovs-brcompatd daemon.