</screen>
<para>This command will allocate the sub-directory
<literal>remote_dir</literal> onto the MDT of index
- <literal>mdtindex</literal>. For more information on adding additional MDTs
+ <literal>mdt_index</literal>. For more information on adding additional MDTs
and
- <literal>mdtindex</literal> see
+ <literal>mdt_index</literal> see
<xref linkend='dbdoclet.addmdtindex' />.</para>
<warning>
<para>An administrator can allocate remote sub-directories to separate
will leave the namespace below it inaccessible. For this reason, by
default it is only possible to create remote sub-directories off MDT0. To
relax this restriction and enable remote sub-directories off any MDT, an
- administrator must issue the command
- <literal>lctl set_param mdt.*.enable_remote_dir=1</literal>.</para>
+ administrator must issue the following command on the MGS:
+ <screen>mgs# lctl conf_param <replaceable>fsname</replaceable>.mdt.enable_remote_dir=1</screen>
+ For Lustre filesystem 'scratch', the command executed is:
+ <screen>mgs# lctl conf_param scratch.mdt.enable_remote_dir=1</screen>
+ To verify the configuration setting execute the following command on any
+ MDS:
+ <screen>mds# lctl get_param mdt.*.enable_remote_dir</screen></para>
</warning>
<para condition='l28'>With Lustre software version 2.8, a new
tunable is available to allow users with a specific group ID to create
parameter to the 'wheel' or 'admin' group ID allows users with that GID
to create and delete remote and striped directories. Setting this
parameter to <literal>-1</literal> on MDT0 to permanently allow any
- non-root users create and delete remote and striped directories. For
- example:
- <screen>lctl set_param -P mdt.*.enable_remote_dir_gid=-1</screen>
+ non-root users create and delete remote and striped directories.
+ On the MGS execute the following command:
+ <screen>mgs# lctl conf_param <replaceable>fsname</replaceable>.mdt.enable_remote_dir_gid=-1</screen>
+ For the Lustre filesystem 'scratch', the commands expands to:
+ <screen>mgs# lctl conf_param scratch.mdt.enable_remote_dir_gid=-1</screen>.
+ The change can be verified by executing the following command on every MDS:
+ <screen>mds# lctl get_param mdt.<replaceable>*</replaceable>.enable_remote_dir_gid</screen>
</para>
</section>
<section xml:id="dbdoclet.lfsmkdirdne2" condition='l28'>
<primary>striping</primary>
<secondary>metadata</secondary>
</indexterm>Creating a directory striped across multiple MDTs</title>
- <para>Lustre 2.8 enables individual files in a given directory to
- record their metadata on separate MDTs (a <emphasis>striped
- directory</emphasis>). The result of this is that metadata requests for
+ <para>The Lustre 2.8 DNE feature enables individual files in a given
+ directory to store their metadata on separate MDTs (a <emphasis>striped
+ directory</emphasis>) once additional MDTs have been added to the
+ filesystem, see <xref linkend="dbdoclet.addingamdt"/>.
+ The result of this is that metadata requests for
files in a striped directory are serviced by multiple MDTs and metadata
service load is distributed over all the MDTs that service a given
directory. By distributing metadata service load over multiple MDTs,
performance. Prior to the development of this feature all files in a
directory must record their metadata on a single MDT.</para>
<para>This command to stripe a directory over
- <replaceable>mdt_count</replaceable> MDTs is:
- </para>
+ <replaceable>mdt_count</replaceable> MDTs is:
+ </para>
<screen>
-client# lfs setdirstripe -c
+client# lfs mkdir -c
<replaceable>mdt_count</replaceable>
<replaceable>/mount_point/new_directory</replaceable>
</screen>
+ <para>The striped directory feature is most useful for distributing
+ single large directories (50k entries or more) across multiple MDTs,
+ since it incurs more overhead than non-striped directories.</para>
</section>
<section xml:id="dbdoclet.50438194_88980">
<title>
</section>
<section xml:id="dbdoclet.50438194_88217">
<title>Listing Parameters</title>
- <para>To list Lustre or LNET parameters that are available to set, use
+ <para>To list Lustre or LNet parameters that are available to set, use
the
<literal>lctl list_param</literal> command. For example:</para>
<screen>
<literal>--mgsnode=</literal> or
<literal>--servicenode=</literal>).</para>
<para>To display the NIDs of all servers in networks configured to work
- with the Lustre file system, run (while LNET is running):</para>
+ with the Lustre file system, run (while LNet is running):</para>
<screen>
lctl list_nids
</screen>
/mnt/testfs
mds0# umount /mnt/mdt
mds1# mount -t lustre /dev/sda1 /mnt/test/mdt
-mds1# cat /proc/fs/lustre/mds/testfs-MDT0000/recovery_status
+mds1# lctl get_param mdt.testfs-MDT0000.recovery_status
</screen>
<para>Where multiple NIDs are specified separated by commas (for example,
<literal>10.67.73.200@tcp,192.168.10.1@tcp</literal>), the two NIDs refer
to the same host, and the Lustre software chooses the
- <emphasis>best</emphasis>one for communication. When a pair of NIDs is
+ <emphasis>best</emphasis> one for communication. When a pair of NIDs is
separated by a colon (for example,
<literal>10.67.73.200@tcp:10.67.73.201@tcp</literal>), the two NIDs refer
to two different hosts and are treated as a failover pair (the Lustre
</indexterm>Replacing an Existing OST or MDT</title>
<para>To copy the contents of an existing OST to a new OST (or an old MDT
to a new MDT), follow the process for either OST/MDT backups in
- <xref linkend='dbdoclet.50438207_71633' />or
- <xref linkend='dbdoclet.50438207_21638' />. For more information on
- removing a MDT, see
+ <xref linkend='dbdoclet.backup_device' />or
+ <xref linkend='dbdoclet.backup_target_filesystem' />.
+ For more information on removing a MDT, see
<xref linkend='dbdoclet.rmremotedir' />.</para>
</section>
<section xml:id="dbdoclet.50438194_30872">
git://git.whamcloud.com / doc / manual.git / blobdiff