Lustre versioning
=================

This document describes versioning of source and binaries for Lustre.

Versions
========

The Lustre build version is set in lustre/autoconf/lustre-version.ac
file with the LUSTRE_MAJOR, LUSTRE_MINOR, LUSTRE_PATCH, and LUSTRE_FIX
fields.  These are used to generate the LUSTRE_VERSION string and the
LUSTRE_VERSION_CODE in lustre/include/lustre_ver.h.

LUSTRE_VERSION_CODE can be used in conjunction with OBD_OCD_VERSION()
to conditionally enable functionality by Lustre version, or to mark
some part of code obsolete when a future version of Lustre is built.
It is preferable to mark code obsolete starting at the x.y.50 build
so that it is removed early in the development cycle.

Packages
========

Major releases should get a 3-digit version x.y.0, and if a maintenance
release is needed it will increment the 3rd digit.  During development,
versions start at x.y.50 and increment toward the x.(y+1).0 release.

Release candidate versions must have the proper build version for the
release, but are tagged in Git as v2_1_0_RC1.  Final release versions
are tagged in Git as both v2_1_0_0 and 2.1.0.

Usage:
------

New numbers are used as follows:

1. major:
 - increased when major new functionality becomes available
2. minor:
 - for each new release with new functionality
3. patch:
 - for a stable maintenance release or development snapshot
4. test:
 - when developers feel it is time to exchange a named version

What will run, what won't ?
---------------------------

1. If the test level is non-zero, i.e. there are 4 digits in the
   version, no guarantees of any kind are made.

2. For three digit releases/tags the code should perform
   according to the announcement.