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     ============ ==============
  70
  71     Open vSwitch userspace should also work with the Linux kernel module built
  72     into Linux 3.3 and later.
  73
  74     Open vSwitch userspace is not sensitive to the Linux kernel version.  It
  75     should build against almost any kernel, certainly against 2.6.32 and later.
  76
  77 Q: Are all features available with all datapaths?
  78
  79     A: Open vSwitch supports different datapaths on different platforms.  Each
  80     datapath has a different feature set: the following tables try to summarize
  81     the status.
  82
  83     Supported datapaths:
  84
  85     Linux upstream
  86       The datapath implemented by the kernel module shipped with Linux
  87       upstream.  Since features have been gradually introduced into the kernel,
  88       the table mentions the first Linux release whose OVS module supports the
  89       feature.
  90
  91     Linux OVS tree
  92       The datapath implemented by the Linux kernel module distributed with the
  93       OVS source tree.
  94
  95     Userspace
  96       Also known as DPDK, dpif-netdev or dummy datapath. It is the only
  97       datapath that works on NetBSD, FreeBSD and Mac OSX.
  98
  99     Hyper-V
 100       Also known as the Windows datapath.
 101
 102     The following table lists the datapath supported features from an Open
 103     vSwitch user's perspective.
 104
 105     ===================== ============== ============== ========= =======
 106     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 107     ===================== ============== ============== ========= =======
 108     NAT                   4.6            YES            Yes       NO
 109     Connection tracking   4.3            YES            PARTIAL   PARTIAL
 110     Tunnel - LISP         NO             YES            NO        NO
 111     Tunnel - STT          NO             YES            NO        YES
 112     Tunnel - GRE          3.11           YES            YES       YES
 113     Tunnel - VXLAN        3.12           YES            YES       YES
 114     Tunnel - Geneve       3.18           YES            YES       YES
 115     Tunnel - GRE-IPv6     NO             NO             YES       NO
 116     Tunnel - VXLAN-IPv6   4.3            YES            YES       NO
 117     Tunnel - Geneve-IPv6  4.4            YES            YES       NO
 118     QoS - Policing        YES            YES            YES       NO
 119     QoS - Shaping         YES            YES            NO        NO
 120     sFlow                 YES            YES            YES       NO
 121     IPFIX                 3.10           YES            YES       NO
 122     Set action            YES            YES            YES       PARTIAL
 123     NIC Bonding           YES            YES            YES       YES
 124     Multiple VTEPs        YES            YES            YES       YES
 125     ===================== ============== ============== ========= =======
 126
 127     Do note, however:
 128
 129     * Only a limited set of flow fields is modifiable via the set action by the
 130       Hyper-V datapath.
 131
 132     The following table lists features that do not *directly* impact an Open
 133     vSwitch user, e.g. because their absence can be hidden by the ofproto layer
 134     (usually this comes with a performance penalty).
 135
 136     ===================== ============== ============== ========= =======
 137     Feature               Linux upstream Linux OVS tree Userspace Hyper-V
 138     ===================== ============== ============== ========= =======
 139     SCTP flows            3.12           YES            YES       YES
 140     MPLS                  3.19           YES            YES       YES
 141     UFID                  4.0            YES            YES       NO
 142     Megaflows             3.12           YES            YES       NO
 143     Masked set action     4.0            YES            YES       NO
 144     Recirculation         3.19           YES            YES       YES
 145     TCP flags matching    3.13           YES            YES       NO
 146     Validate flow actions YES            YES            N/A       NO
 147     Multiple datapaths    YES            YES            YES       NO
 148     Tunnel TSO - STT      N/A            YES            NO        YES
 149     ===================== ============== ============== ========= =======
 150
 151 Q: What DPDK version does each Open vSwitch release work with?
 152
 153     A: The following table lists the DPDK version against which the given
 154     versions of Open vSwitch will successfully build.
 155
 156     ============ =======
 157     Open vSwitch DPDK
 158     ============ =======
 159     2.2.x        1.6
 160     2.3.x        1.6
 161     2.4.x        2.0
 162     2.5.x        2.2
 163     2.6.x        16.07.2
 164     2.7.x        16.11.2
 165     2.8.x        17.05.1
 166     ============ =======
 167
 168 Q: I get an error like this when I configure Open vSwitch:
 169
 170         configure: error: Linux kernel in <dir> is version <x>, but
 171         version newer than <y> is not supported (please refer to the
 172         FAQ for advice)
 173
 174     What should I do?
 175
 176     A: You have the following options:
 177
 178     - Use the Linux kernel module supplied with the kernel that you are using.
 179       (See also the following FAQ.)
 180
 181     - If there is a newer released version of Open vSwitch, consider building
 182       that one, because it may support the kernel that you are building
 183       against.  (To find out, consult the table in the previous FAQ.)
 184
 185     - The Open vSwitch "master" branch may support the kernel that you are
 186       using, so consider building the kernel module from "master".
 187
 188     All versions of Open vSwitch userspace are compatible with all versions of
 189     the Open vSwitch kernel module, so you do not have to use the kernel module
 190     from one source along with the userspace programs from the same source.
 191
 192 Q: What features are not available in the Open vSwitch kernel datapath that
 193 ships as part of the upstream Linux kernel?
 194
 195     A: The kernel module in upstream Linux does not include support for LISP.
 196     Work is in progress to add support for LISP to the upstream Linux version
 197     of the Open vSwitch kernel module. For now, if you need this feature, use
 198     the kernel module from the Open vSwitch distribution instead of the
 199     upstream Linux kernel module.
 200
 201     Certain features require kernel support to function or to have reasonable
 202     performance. If the ovs-vswitchd log file indicates that a feature is not
 203     supported, consider upgrading to a newer upstream Linux release or using
 204     the kernel module paired with the userspace distribution.
 205
 206 Q: Why do tunnels not work when using a kernel module other than the one
 207 packaged with Open vSwitch?
 208
 209     A: Support for tunnels was added to the upstream Linux kernel module after
 210     the rest of Open vSwitch. As a result, some kernels may contain support for
 211     Open vSwitch but not tunnels. The minimum kernel version that supports each
 212     tunnel protocol is:
 213
 214     ======== ============
 215     Protocol Linux Kernel
 216     ======== ============
 217     GRE      3.11
 218     VXLAN    3.12
 219     Geneve   3.18
 220     LISP     not upstream
 221     STT      not upstream
 222     ======== ============
 223
 224     If you are using a version of the kernel that is older than the one listed
 225     above, it is still possible to use that tunnel protocol. However, you must
 226     compile and install the kernel module included with the Open vSwitch
 227     distribution rather than the one on your machine. If problems persist after
 228     doing this, check to make sure that the module that is loaded is the one
 229     you expect.
 230
 231 Q: Why are UDP tunnel checksums not computed for VXLAN or Geneve?
 232
 233     A: Generating outer UDP checksums requires kernel support that was not part
 234     of the initial implementation of these protocols. If using the upstream
 235     Linux Open vSwitch module, you must use kernel 4.0 or newer. The
 236     out-of-tree modules from Open vSwitch release 2.4 and later support UDP
 237     checksums.
 238
 239 Q: What features are not available when using the userspace datapath?
 240
 241     A: Tunnel virtual ports are not supported, as described in the previous
 242     answer.  It is also not possible to use queue-related actions.  On Linux
 243     kernels before 2.6.39, maximum-sized VLAN packets may not be transmitted.
 244
 245 Q: Should userspace or kernel be upgraded first to minimize downtime?
 246
 247     A. In general, the Open vSwitch userspace should be used with the kernel
 248     version included in the same release or with the version from upstream
 249     Linux.  However, when upgrading between two releases of Open vSwitch it is
 250     best to migrate userspace first to reduce the possibility of
 251     incompatibilities.
 252
 253 Q: What happened to the bridge compatibility feature?
 254
 255     A: Bridge compatibility was a feature of Open vSwitch 1.9 and earlier.
 256     When it was enabled, Open vSwitch imitated the interface of the Linux
 257     kernel "bridge" module.  This allowed users to drop Open vSwitch into
 258     environments designed to use the Linux kernel bridge module without
 259     adapting the environment to use Open vSwitch.
 260
 261     Open vSwitch 1.10 and later do not support bridge compatibility.  The
 262     feature was dropped because version 1.10 adopted a new internal
 263     architecture that made bridge compatibility difficult to maintain.  Now
 264     that many environments use OVS directly, it would be rarely useful in any
 265     case.
 266
 267     To use bridge compatibility, install OVS 1.9 or earlier, including the
 268     accompanying kernel modules (both the main and bridge compatibility
 269     modules), following the instructions that come with the release.  Be sure
 270     to start the ovs-brcompatd daemon.