LUDOC-371 config: Add lctl 'clear_conf' documentation.

The new lctl command "clear_conf" is added to allow
administartors to clear configuration files by removing
SKIP records. The old configuration files are backed up.

Signed-off-by: Arshad Hussain <arshad.hussain@seagate.com>
Signed-off-by: Vladimir Saveliev <vladimir.saveliev@seagate.com>
Change-Id: Iacc52127b0b93e736430cc13d4c9c852eac8dc2d
Seagate-bug-id: MRP-2091
Reviewed-on: https://review.whamcloud.com/26083
Tested-by: Jenkins
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Joseph Gmitter <jgmitter@whamcloud.com>

diff --git a/LustreMaintenance.xml b/LustreMaintenance.xml
index dfeaa6f..12b8267 100644 (file)
--- a/LustreMaintenance.xml
+++ b/LustreMaintenance.xml
@@ -281,6 +281,57 @@ Changing a Server NID</title>
       <note><para>The previous configuration log is backed up on the MGS
       disk with the suffix <literal>'.bak'</literal>.</para></note>
     </section>
+    <section xml:id="dbdoclet.clear_conf" condition="l2B">
+      <title><indexterm>
+           <primary>maintenance</primary>
+               <secondary>Clearing a config</secondary>
+         </indexterm> Clearing configuration</title>
+      <para>
+         This command runs on MGS node having the MGS device mounted with
+         <literal>-o nosvc.</literal> It cleans up configuration files
+         stored in the CONFIGS/ directory of any records marked SKIP.
+         If the device name is given, then the specific logs for that
+         filesystem (e.g. testfs-MDT0000) are processed.  Otherwise, if a
+         filesystem name is given then all configuration files are cleared.
+         The previous configuration log is backed up on the MGS disk with
+         the suffix 'config.timestamp.bak'. Eg: Lustre-MDT0000-1476454535.bak.
+         </para>
+         <para> To clear a configuration:</para>
+         <orderedlist>
+            <listitem>
+                  <para>Shut down the file system in this order:</para>
+             <orderedlist>
+               <listitem>
+                 <para>Unmount the clients.</para>
+               </listitem>
+               <listitem>
+                 <para>Unmount the MDT.</para>
+               </listitem>
+               <listitem>
+                 <para>Unmount all OSTs.</para>
+               </listitem>
+             </orderedlist>
+            </listitem>
+            <listitem>
+              <para>
+                If the MGS and MDS share a partition, start the MGS only
+                using "nosvc" option.
+              </para>
+           <screen>mount -t lustre <replaceable>MDT partition</replaceable> -o nosvc <replaceable>mount_point</replaceable></screen>
+            </listitem>
+            <listitem>
+                <para>Run the <literal>clear_conf</literal> command on the MGS:
+                </para>
+           <screen>lctl clear_conf <replaceable>config</replaceable></screen>
+            <para>
+                       Example: To clear the configuration for
+                       <literal>MDT0000</literal> on a filesystem named
+                       <literal>testfs</literal>
+            </para>
+           <screen>mgs# lctl clear_conf testfs-MDT0000</screen>
+            </listitem>
+          </orderedlist>
+       </section>
     <section xml:id="dbdoclet.adding_new_mdt" condition='l24'>
       <title><indexterm>
         <primary>maintenance</primary>