openstack/nova
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docs: Move the LibvirtDistroSupportMatrix wiki page into our docs

Browse Source 
This change moves the LibvirtDistroSupportMatrix [1] wiki page into the
tree as a reference doc. The wiki page will be decommissioned once this
change lands and is published.

Some older distro information is removed to keep the table readable and
a note is added to driver.py to ensure it updated with each version
bump.

[1] https://wiki.openstack.org/wiki/LibvirtDistroSupportMatrix

Change-Id: Id49a4e400159130fbc676800aeca6b9746071a2e
This commit is contained in:
Lee Yarwood 2021-01-22 13:50:47 +00:00
parent 0c53f4bde8
commit a19d25b67f
3 changed files with 310 additions and 14 deletions
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4
doc/source/reference/index.rst
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@ -40,7 +40,8 @@ The following is a dive into some of the internals in nova.
* :doc:`/reference/attach-volume`: Describes the attach volume flow, using the
libvirt virt driver as an example.
* :doc:`/reference/block-device-structs`: Block Device Data Structures
* :doc:`/reference/libvirt-distro-support-matrix`: Libvirt virt driver OS
distribution support matrix
.. # NOTE(amotoki): toctree needs to be placed at the end of the secion to
# keep the document structure in the PDF doc.
@ -62,6 +63,7 @@ The following is a dive into some of the internals in nova.
api-microversion-history
attach-volume
block-device-structs
libvirt-distro-support-matrix
Debugging
=========

303
doc/source/reference/libvirt-distro-support-matrix.rst Normal file
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@ -0,0 +1,303 @@
Libvirt virt driver OS distribution support matrix
==================================================
This page documents the libvirt versions present in the various distro versions
that OpenStack Nova aims to be deployable with.
.. note::
This document was previously hosted on the OpenStack wiki:
https://wiki.openstack.org/wiki/LibvirtDistroSupportMatrix
Libvirt minimum version change policy
-------------------------------------
At the start of each Nova development cycle this matrix will be consulted to
determine if it is viable to drop support for any end-of-life or otherwise
undesired distro versions. Based on this distro evaluation, it may be possible
to increase the minimum required version of libvirt in Nova, and thus drop some
compatibility code for older versions.
When a decision to update the minimum required libvirt version is made, there
must be a warning issued for one cycle. This is achieved by editing
``nova/virt/libvirt/driver.py`` to set ``NEXT_MIN_LIBVIRT_VESION``.
For example:
.. code::
NEXT_MIN_LIBVIRT_VERSION = (X, Y, Z)
This causes a deprecation warning to be emitted when Nova starts up warning the
admin that the version of libvirt in use on the host will no longer be
supported in the subsequent release.
After a version has been listed in ``NEXT_MIN_LIBVIRT_VERSION`` for one release
cycle, the corresponding actual minimum required libvirt can be updated by
setting
.. code::
MIN_LIBVIRT_VERSION = (X, Y, Z)
At this point of course, an even newer version might be set in
``NEXT_MIN_LIBVIRT_VERSION`` to repeat the process....
An email should also be sent at this point to the
``openstack-discuss@lists.openstack.org`` mailing list as a courtesy raising
awareness of the change in minimum version requirements in the upcoming
release, for example:
http://lists.openstack.org/pipermail/openstack-discuss/2021-January/019849.html
There is more background on the rationale used for picking minimum versions in
the operators mailing list thread here:
http://lists.openstack.org/pipermail/openstack-operators/2015-May/007012.html
QEMU minimum version change policy
----------------------------------
After choosing a minimum libvirt version, the minimum QEMU version is
determined by looking for the lowest QEMU version from all the distros that
support the decided libvirt version.
``MIN_{LIBVIRT,QEMU}_VESION`` and ``NEXT_MIN_{LIBVIRT,QEMU}_VESION`` table
--------------------------------------------------------------------------
.. list-table:: OpenStack Nova libvirt/QEMU Support Matrix
* - OpenStack Release
- Nova Release
- ``MIN_LIBVIRT_VESION``
- ``NEXT_MIN_LIBVIRT_VESION``
- ``MIN_QEMU_VESION``
- ``NEXT_MIN_QEMU_VESION``
* - Havana
- 2013.2.0
- 0.9.6
- 0.9.6
-
-
* - Icehouse
- 2014.1
- 0.9.6
- 0.9.11
-
-
* - Juno
- 2014.2.0
- 0.9.11
- 0.9.11
-
-
* - Kilo
- 2015.1.0
- 0.9.11
- 0.9.11
-
-
* - Liberty
- 12.0.0
- 0.9.11
- 0.10.2
-
-
* - Mitaka
- 13.0.0
- 0.10.2
- 1.2.1
-
-
* - Newton
- 14.0.0
- 1.2.1
- 1.2.1
- 1.5.3
- 1.5.3
* - Ocata
- 15.0.0
- 1.2.1
- 1.2.9
- 1.5.3
- 2.1.0
* - Pike
- 16.0.0
- 1.2.9
- 1.3.1
- 2.1.0
- 2.5.0
* - Queens
- 17.0.0
- 1.2.9
- 1.3.1
- 2.1.0
- 2.5.0
* - Rocky
- 18.0.0
- 1.3.1
- 3.0.0
- 2.5.0
- 2.8.0
* - Stein
- 19.0.0
- 3.0.0
- 4.0.0
- 2.8.0
- 2.11.0
* - Train
- 20.0.0
- 3.0.0
- 4.0.0
- 2.8.0
- 2.11.0
* - Ussuri
- 21.0.0
- 4.0.0
- 5.0.0
- 2.11.0
- 4.0.0
* - Victoria
- 22.0.0
- 5.0.0
- 6.0.0
- 4.0.0
- 4.2.0
* - Wallaby
- 23.0.0
- 6.0.0
- 7.0.0
- 4.2.0
- 5.2.0
OS distribution versions
------------------------
This table provides information on a representative sample of OS distros and
the version of libirt/QEMU/libguestfs that they ship. This is **NOT** intended
to be an exhaustive list of distros where OpenStack Nova can run - it is
intended to run on any Linux distro that can satisfy the minimum required
software versions. This table merely aims to help identify when minimum
required versions can be reasonably updated without losing support for
important OS distros.
.. list-table:: Distro libvirt/QEMU Support Table
* - OS Distro
- GA date
- Libvirt
- QEMU/KVM
- libguestfs
* - **Debian**
-
-
-
-
* - 10.x (Buster) ("stable")
- as of 2020-05-15
- 5.0.0
- 3.1
- 1.40
* - 11.x (Bullseye) ("sid" - unstable)
- No GA date as of 2020-05-15
- 6.0.0
- 5.0
- 1.42.0
* - **Fedora**
-
-
-
-
* - 32
- 2020-04-28
- 6.1.0
- 4.2.0
- 1.42.0
* - 33
- 2020-10-27
- 6.6.0
- 5.1.0
- 1.43.0
* - **SUSE**
-
-
-
-
* - Leap 15.0
- 2018-05
- 4.0.0
- 2.11.1
- 1.38.0
* - Leap 15.1
- 2019-05-22
- 5.1.0
- 3.1.1
- 1.38.0
* - Leap 15.2
- 2020-07-02 (scheduled)
- 6.0.0
- 4.2.0
- 1.38.0
* - **RHEL**
-
-
-
-
* - 7.7
- 2019-08-06
- 4.5.0-23
- 2.12.0-33
- 1.40.2-5
* - 7.8
- 2020-03-31
- 4.5.0-36
- 2.12.0-48
- 1.40.2-10
* - 8.2
- 2020-04-28
- 6.0.0-17.2
- 4.2.0-19
- 1.40.2-22
* - 8.3
- 2020-10-29
- 6.0.0-25.5
- 4.2.0-29
- 1.40.2-24
* - **SLES**
-
-
-
-
* - 15
- 2018-07
- 4.0.0
- 2.11.1
- 1.38.0
* - 15.1
- 2019
- 5.1.0
- 3.1.1
- 1.38.0
* - 15.2
- 2020
- 6.0.0
- 4.2.1
- 1.38.0
* - **Ubuntu**
-
-
-
-
* - 18.04 (Bionic LTS - Cloud Archive)
- as of 2019-11-18
- 5.4
- 4.0
- 1.36
* - 20.04 (Focal Fossa)
- 2020-04-23
- 6.0.0
- 4.2
- 1.40.2
.. NB: maintain alphabetical ordering of distros, followed by oldest released
versions first

17
nova/virt/libvirt/driver.py
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@ -211,23 +211,14 @@ def patch_tpool_proxy():
patch_tpool_proxy()
# For information about when MIN_LIBVIRT_VERSION and
# NEXT_MIN_LIBVIRT_VERSION can be changed, consult
# For information about when MIN_{LIBVIRT,QEMU}_VERSION and
# NEXT_MIN_{LIBVIRT,QEMU}_VERSION can be changed, consult the following:
#
# https://wiki.openstack.org/wiki/LibvirtDistroSupportMatrix
# doc/source/reference/libvirt-distro-support-matrix.rst
#
# Currently this is effectively the min version for i686/x86_64
# + KVM/QEMU, as other architectures/hypervisors require newer
# versions. Over time, this will become a common min version
# for all architectures/hypervisors, as this value rises to
# meet them.
# DO NOT FORGET to update this document when touching any versions below!
MIN_LIBVIRT_VERSION = (6, 0, 0)
MIN_QEMU_VERSION = (4, 2, 0)
# TODO(berrange): Re-evaluate this at start of each release cycle
# to decide if we want to plan a future min version bump.
# MIN_LIBVIRT_VERSION can be updated to match this after
# NEXT_MIN_LIBVIRT_VERSION has been at a higher value for
# one cycle
NEXT_MIN_LIBVIRT_VERSION = (7, 0, 0)
NEXT_MIN_QEMU_VERSION = (5, 2, 0)