ref-manual/structure.rst: extend PERSISTENT_DIR description

Extend the description of PERSISTENT_DIR to mention that it should not
be shared between builds. Add a note on sharing the hash equivalence
database by setting up a server and not sharing the file in this
directory.

[YOCTO #15727]

(From yocto-docs rev: 0ff0233770b77f9e74f4241dfb555dac2741d8b9)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/documentation/ref-manual/structure.rst b/documentation/ref-manual/structure.rst
index c9c44bc633..660cc9be1b 100644
--- a/documentation/ref-manual/structure.rst
+++ b/documentation/ref-manual/structure.rst
@@ -253,6 +253,17 @@ It also contains ``sanity_info``, a text file keeping track of important
 build information such as the values of :term:`TMPDIR`, :term:`SSTATE_DIR`,
 as well as the name and version of the host distribution.
 
+This directory should not be shared between builds.
+
+.. note::
+
+   The default location of the :ref:`overview-manual/concepts:Hash Equivalence`
+   database is this directory (when :term:`BB_HASHSERVE` is set to ``auto``). If
+   you need to share the :ref:`overview-manual/concepts:Hash Equivalence`
+   database, don't share this file and instead refer to the
+   :doc:`/dev-manual/hashequivserver` document of the Yocto Project Development
+   Tasks Manual to setup Hash Equivalence server.
+
 .. _structure-build-conf-local.conf:
 
 ``build/conf/local.conf``