ref-manual: New VOLATILE_LOG_DIR variable description

Fixes [YOCTO #6132]

No mention of how to make the target directory /var/log
persistent.  I added a note to the "post-install-logging"
image feature that points to the new VOLATILE_LOG_DIR
variable description, which I added to the glossary.

(From yocto-docs rev: 5d2bdf49e569e44d02602501d72418f04dbe6e4a)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 31 insertions, 3 deletions

diff --git a/documentation/ref-manual/ref-features.xml b/documentation/ref-manual/ref-features.xml
index 282a517191..a4516a2665 100644
--- a/documentation/ref-manual/ref-features.xml
+++ b/documentation/ref-manual/ref-features.xml
@@ -297,6 +297,12 @@
                     Enables logging postinstall script runs to
                     the <filename>/var/log/postinstall.log</filename> file
                     on first boot of the image on the target system.
+                    <note>
+                        To make the <filename>/var/log</filename> directory
+                        on the target persistent, use the
+                        <ulink url='&YOCTO_DOCS_REF_URL;#var-VOLATILE_LOG_DIR'><filename>VOLATILE_LOG_DIR</filename></ulink>
+                        variable by setting it to "no".
+                    </note>
                     </para></listitem>
                 <listitem><para><emphasis>ptest-pkgs:</emphasis>
                     Installs ptest packages for all ptest-enabled recipes.
diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index a696ee4e66..6e15e65f54 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -37,7 +37,7 @@
        <link linkend='var-S'>S</link>
        <link linkend='var-T'>T</link>
        <link linkend='var-UBOOT_CONFIG'>U</link>
-<!--               <link linkend='var-glossary-v'>V</link> -->
+       <link linkend='var-VOLATILE_LOG_DIR'>V</link>
        <link linkend='var-WARN_QA'>W</link>
        <link linkend='var-XSERVER'>X</link>
 <!--               <link linkend='var-glossary-y'>Y</link> -->
@@ -15544,8 +15544,30 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
 
     </glossdiv>
 
-<!--            <glossdiv id='var-glossary-v'><title>V</title>-->
-<!--            </glossdiv>-->
+    <glossdiv id='var-glossary-v'><title>V</title>
+
+        <glossentry id='var-VOLATILE_LOG_DIR'><glossterm>VOLATILE_LOG_DIR</glossterm>
+            <info>
+               VOLATILE_LOG_DIR[doc] = "Specifies the persistence of the target's /var/log directory, which is used to house postinstall target log files."
+            </info>
+            <glossdef>
+                <para role="glossdeffirst">
+<!--                <para role="glossdeffirst"><imagedata fileref="figures/define-generic.png" /> -->
+                    Specifies the persistence of the target's
+                    <filename>/var/log</filename> directory, which is used to
+                    house postinstall target log files.
+                </para>
+
+                <para>
+                    By default, <filename>VOLATILE_LOG_DIR</filename> is set
+                    to "yes", which means the file is not persistent.
+                    You can override this setting by setting the
+                    variable to "no" to make the log directory persistent.
+                </para>
+            </glossdef>
+        </glossentry>
+
+    </glossdiv>
 
     <glossdiv id='var-glossary-w'><title>W</title>