</title>
<para>Because changelog records take up space on the MDT, the system administration must register changelog users. The registrants specify which records they are "done with", and the system purges up to the greatest common record.</para>
<para>To register a new changelog user, run:</para>
- <screen>lctl --device <mdt_device> changelog_register
+ <screen>lctl --device /dev/<replaceable>mdt_device</replaceable> changelog_register
</screen>
<para>Changelog entries are not purged beyond a registered user's set point (see <literal>lfs changelog_clear</literal>).</para>
</section>
<literal>lfs changelog</literal>
</title>
<para>To display the metadata changes on an MDT (the changelog records), run:</para>
- <screen>lfs changelog <MDT name> [startrec [endrec]] </screen>
+ <screen>lfs changelog <replaceable>fsname</replaceable>-<replaceable>MDTnumber</replaceable> [startrec [endrec]] </screen>
<para>It is optional whether to specify the start and end records.</para>
<para>These are sample changelog records:</para>
<screen>2 02MKDIR 4298396676 0x0 t=[0x200000405:0x15f9:0x0] p=[0x13:0x15e5a7a3:0x0]\
<literal>lfs changelog_clear</literal>
</title>
<para>To clear old changelog records for a specific user (records that the user no longer needs), run:</para>
- <screen>lfs changelog_clear <MDT name> <user ID> <endrec></screen>
- <para>The <literal>changelog_clear</literal> command indicates that changelog records previous to <endrec> are no longer of interest to a particular user <user ID>, potentially allowing the MDT to free up disk space. An <literal><endrec></literal> value of 0 indicates the current last record. To run <literal>changelog_clear</literal>, the changelog user must be registered on the MDT node using <literal>lctl</literal>.</para>
+ <screen>lfs changelog_clear <replaceable>mdt_name</replaceable> <replaceable>userid</replaceable> <replaceable>endrec</replaceable></screen>
+ <para>The <literal>changelog_clear</literal> command indicates that changelog records previous to <replaceable>endrec</replaceable> are no longer of interest to a particular user <replaceable>userid</replaceable>, potentially allowing the MDT to free up disk space. An <literal><replaceable>endrec</replaceable></literal> value of 0 indicates the current last record. To run <literal>changelog_clear</literal>, the changelog user must be registered on the MDT node using <literal>lctl</literal>.</para>
<para>When all changelog users are done with records < X, the records are deleted.</para>
</section>
<section remap="h5">
<literal>lctl changelog_deregister</literal>
</title>
<para>To deregister (unregister) a changelog user, run:</para>
- <screen>lctl --device <mdt_device> changelog_deregister <user ID> </screen>
+ <screen>lctl --device <replaceable>mdt_device</replaceable> changelog_deregister <replaceable>userid</replaceable> </screen>
<para> <literal>changelog_deregister cl1</literal> effectively does a <literal>changelog_clear cl1 0</literal> as it deregisters.</para>
</section>
</section>