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 4.15
  70     ============ ==============
  71
  72     Open vSwitch userspace should also work with the Linux kernel module built
  73     into Linux 3.3 and later.
  74
  75     Open vSwitch userspace is not sensitive to the Linux kernel version.  It
  76     should build against almost any kernel, certainly against 2.6.32 and later.
  77
  78 Q: Are all features available with all datapaths?
  79
  80     A: Open vSwitch supports different datapaths on different platforms.  Each
  81     datapath has a different feature set: the following tables try to summarize
  82     the status.
  83
  84     Supported datapaths:
  85
  86     Linux upstream
  87       The datapath implemented by the kernel module shipped with Linux
  88       upstream.  Since features have been gradually introduced into the kernel,
  89       the table mentions the first Linux release whose OVS module supports the
  90       feature.
  91
  92     Linux OVS tree
  93       The datapath implemented by the Linux kernel module distributed with the
  94       OVS source tree.
  95
  96     Userspace
  97       Also known as DPDK, dpif-netdev or dummy datapath. It is the only
  98       datapath that works on NetBSD, FreeBSD and Mac OSX.
  99
 100     Hyper-V
 101       Also known as the Windows datapath.
 102
 103     The following table lists the datapath supported features from an Open
 104     vSwitch user's perspective.
 105
 106     ===================== ============== ============== ========= =======
 107     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 108     ===================== ============== ============== ========= =======
 109     NAT                   4.6            YES            Yes       NO
 110     Connection tracking   4.3            YES            PARTIAL   PARTIAL
 111     Tunnel - LISP         NO             YES            NO        NO
 112     Tunnel - STT          NO             YES            NO        YES
 113     Tunnel - GRE          3.11           YES            YES       YES
 114     Tunnel - VXLAN        3.12           YES            YES       YES
 115     Tunnel - Geneve       3.18           YES            YES       YES
 116     Tunnel - GRE-IPv6     NO             NO             YES       NO
 117     Tunnel - VXLAN-IPv6   4.3            YES            YES       NO
 118     Tunnel - Geneve-IPv6  4.4            YES            YES       NO
 119     QoS - Policing        YES            YES            YES       NO
 120     QoS - Shaping         YES            YES            NO        NO
 121     sFlow                 YES            YES            YES       NO
 122     IPFIX                 3.10           YES            YES       NO
 123     Set action            YES            YES            YES       PARTIAL
 124     NIC Bonding           YES            YES            YES       YES
 125     Multiple VTEPs        YES            YES            YES       YES
 126     ===================== ============== ============== ========= =======
 127
 128     Do note, however:
 129
 130     * Only a limited set of flow fields is modifiable via the set action by the
 131       Hyper-V datapath.
 132
 133     The following table lists features that do not *directly* impact an Open
 134     vSwitch user, e.g. because their absence can be hidden by the ofproto layer
 135     (usually this comes with a performance penalty).
 136
 137     ===================== ============== ============== ========= =======
 138     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 139     ===================== ============== ============== ========= =======
 140     SCTP flows            3.12           YES            YES       YES
 141     MPLS                  3.19           YES            YES       YES
 142     UFID                  4.0            YES            YES       NO
 143     Megaflows             3.12           YES            YES       NO
 144     Masked set action     4.0            YES            YES       NO
 145     Recirculation         3.19           YES            YES       YES
 146     TCP flags matching    3.13           YES            YES       NO
 147     Validate flow actions YES            YES            N/A       NO
 148     Multiple datapaths    YES            YES            YES       NO
 149     Tunnel TSO - STT      N/A            YES            NO        YES
 150     ===================== ============== ============== ========= =======
 151
 152 Q: What DPDK version does each Open vSwitch release work with?
 153
 154     A: The following table lists the DPDK version against which the given
 155     versions of Open vSwitch will successfully build.
 156
 157     ============ =======
 158     Open vSwitch DPDK
 159     ============ =======
 160     2.2.x        1.6
 161     2.3.x        1.6
 162     2.4.x        2.0
 163     2.5.x        2.2
 164     2.6.x        16.07.2
 165     2.7.x        16.11.5
 166     2.8.x        17.05.2
 167     2.9.x        17.11.1
 168     ============ =======
 169
 170 Q: I get an error like this when I configure Open vSwitch:
 171
 172         configure: error: Linux kernel in <dir> is version <x>, but
 173         version newer than <y> is not supported (please refer to the
 174         FAQ for advice)
 175
 176     What should I do?
 177
 178     A: You have the following options:
 179
 180     - Use the Linux kernel module supplied with the kernel that you are using.
 181       (See also the following FAQ.)
 182
 183     - If there is a newer released version of Open vSwitch, consider building
 184       that one, because it may support the kernel that you are building
 185       against.  (To find out, consult the table in the previous FAQ.)
 186
 187     - The Open vSwitch "master" branch may support the kernel that you are
 188       using, so consider building the kernel module from "master".
 189
 190     All versions of Open vSwitch userspace are compatible with all versions of
 191     the Open vSwitch kernel module, so you do not have to use the kernel module
 192     from one source along with the userspace programs from the same source.
 193
 194 Q: What features are not available in the Open vSwitch kernel datapath that
 195 ships as part of the upstream Linux kernel?
 196
 197     A: The kernel module in upstream Linux does not include support for LISP.
 198     Work is in progress to add support for LISP to the upstream Linux version
 199     of the Open vSwitch kernel module. For now, if you need this feature, use
 200     the kernel module from the Open vSwitch distribution instead of the
 201     upstream Linux kernel module.
 202
 203     Certain features require kernel support to function or to have reasonable
 204     performance. If the ovs-vswitchd log file indicates that a feature is not
 205     supported, consider upgrading to a newer upstream Linux release or using
 206     the kernel module paired with the userspace distribution.
 207
 208 Q: Why do tunnels not work when using a kernel module other than the one
 209 packaged with Open vSwitch?
 210
 211     A: Support for tunnels was added to the upstream Linux kernel module after
 212     the rest of Open vSwitch. As a result, some kernels may contain support for
 213     Open vSwitch but not tunnels. The minimum kernel version that supports each
 214     tunnel protocol is:
 215
 216     ======== ============
 217     Protocol Linux Kernel
 218     ======== ============
 219     GRE      3.11
 220     VXLAN    3.12
 221     Geneve   3.18
 222     LISP     not upstream
 223     STT      not upstream
 224     ======== ============
 225
 226     If you are using a version of the kernel that is older than the one listed
 227     above, it is still possible to use that tunnel protocol. However, you must
 228     compile and install the kernel module included with the Open vSwitch
 229     distribution rather than the one on your machine. If problems persist after
 230     doing this, check to make sure that the module that is loaded is the one
 231     you expect.
 232
 233 Q: Why are UDP tunnel checksums not computed for VXLAN or Geneve?
 234
 235     A: Generating outer UDP checksums requires kernel support that was not part
 236     of the initial implementation of these protocols. If using the upstream
 237     Linux Open vSwitch module, you must use kernel 4.0 or newer. The
 238     out-of-tree modules from Open vSwitch release 2.4 and later support UDP
 239     checksums.
 240
 241 Q: What features are not available when using the userspace datapath?
 242
 243     A: Tunnel virtual ports are not supported, as described in the previous
 244     answer.  It is also not possible to use queue-related actions.  On Linux
 245     kernels before 2.6.39, maximum-sized VLAN packets may not be transmitted.
 246
 247 Q: Should userspace or kernel be upgraded first to minimize downtime?
 248
 249     A. In general, the Open vSwitch userspace should be used with the kernel
 250     version included in the same release or with the version from upstream
 251     Linux.  However, when upgrading between two releases of Open vSwitch it is
 252     best to migrate userspace first to reduce the possibility of
 253     incompatibilities.
 254
 255 Q: What happened to the bridge compatibility feature?
 256
 257     A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.
 258     When it was enabled, Open vSwitch imitated the interface of the Linux
 259     kernel "bridge" module.  This allowed users to drop Open vSwitch into
 260     environments designed to use the Linux kernel bridge module without
 261     adapting the environment to use Open vSwitch.
 262
 263     Open vSwitch 1.10 and later do not support bridge compatibility.  The
 264     feature was dropped because version 1.10 adopted a new internal
 265     architecture that made bridge compatibility difficult to maintain.  Now
 266     that many environments use OVS directly, it would be rarely useful in any
 267     case.
 268
 269     To use bridge compatibility, install OVS 1.9 or earlier, including the
 270     accompanying kernel modules (both the main and bridge compatibility
 271     modules), following the instructions that come with the release.  Be sure
 272     to start the ovs-brcompatd daemon.