</listitem>
<listitem>
<para>
- <xref linkend="dbdoclet.backup_target_filesystem"/>
+ <xref linkend="backup_fs_level"/>
</para>
</listitem>
<listitem>
<para>
- <xref linkend="dbdoclet.restore_target_filesystem"/>
+ <xref linkend="backup_fs_level.restore"/>
</para>
</listitem>
<listitem>
restore is detected (see
<link xl:href="http://jira.hpdd.intel.com/browse/LU-957">LU-957</link>),
and file-level backup is supported (see
- <xref linkend="dbdoclet.backup_target_filesystem"/>).</para>
+ <xref linkend="backup_fs_level"/>).</para>
</warning>
<para>If hardware replacement is the reason for the backup or if a spare
storage device is available, it is possible to do a raw copy of the MDT or
backup device, and is still much better than not having any backup at all.
</para>
</section>
- <section xml:id="dbdoclet.backup_target_filesystem">
+ <section xml:id="backup_fs_level">
<title>
<indexterm>
<primary>backup</primary>
<indexterm>
<primary>backup</primary>
<secondary>MDT file system</secondary>
- </indexterm>Backing Up an OST or MDT (ldiskfs File System Level)</title>
+ </indexterm>Backing Up an OST or MDT (Backend File System Level)</title>
<para>This procedure provides an alternative to backup or migrate the data
of an OST or MDT at the file level. At the file-level, unused space is
- omitted from the backed up and the process may be completed quicker with
+ omitted from the backup and the process may be completed quicker with a
smaller total backup size. Backing up a single OST device is not
necessarily the best way to perform backups of the Lustre file system,
since the files stored in the backup are not usable without metadata stored
it is the preferred method for migration of OST devices, especially when it
is desirable to reformat the underlying file system with different
configuration options or to reduce fragmentation.</para>
- <note>
- <para>Prior to Lustre software release 2.3, the only successful way to
- perform an MDT backup and restore is to do a device-level backup as is
- described in
+ <note><para>
+ <emphasis role="bold">Prior to Lustre software release 2.3</emphasis>, the
+ only successful way to perform an MDT backup and restore was to do a
+ device-level backup as described in
<xref linkend="dbdoclet.backup_device" />. The ability to do MDT
file-level backups is not available for Lustre software release 2.0
through 2.2, because restoration of the Object Index (OI) file does not
- return the MDT to a functioning state.
- <emphasis role="bold">Since Lustre software release 2.3</emphasis>,
+ return the MDT to a functioning state.</para>
+ <para><emphasis role="bold">Since Lustre software release 2.3</emphasis>,
Object Index files are automatically rebuilt at first mount after a
restore is detected (see
<link xl:href="http://jira.hpdd.intel.com/browse/LU-957">LU-957</link>),
- so file-level MDT restore is supported.</para>
- </note>
- <para>For Lustre software release 2.3 and newer with MDT file-level backup
- support, substitute
- <literal>mdt</literal> for
- <literal>ost</literal> in the instructions below.</para>
- <orderedlist>
- <listitem>
- <para>
- <emphasis role="bold">Make a mountpoint for the file
- system.</emphasis>
- </para>
- <screen>[oss]# mkdir -p /mnt/ost</screen>
- </listitem>
- <listitem>
- <para>
- <emphasis role="bold">Mount the file system.</emphasis>
- </para>
+ so file-level MDT restore is supported.</para></note>
+ <section xml:id="backup_fs_level.index_objects" condition="l2B">
+ <title>
+ <indexterm>
+ <primary>backup</primary>
+ <secondary>index objects</secondary>
+ </indexterm>Backing Up an OST or MDT (Backend File System Level)</title>
+ <para>Prior to Lustre software release 2.11.0, we can only do the backend
+ file system level backup and restore process for ldiskfs-based systems.
+ The ability to perform a zfs-based MDT/OST file system level backup and
+ restore is introduced beginning in Lustre software release 2.11.0.
+ Differing from an ldiskfs-based system, index objects must be backed up
+ before the unmount of the target (MDT or OST) in order to be able to
+ restore the file system successfully. To enable index backup on the
+ target, execute the following command on the target server:</para>
+ <screen># lctl set_param osd-zfs.${fsname}-${target}.index_backup=1</screen>
+ <para><replaceable>${target}</replaceable> is composed of the target type
+ (MDT or OST) plus the target index, such as <literal>MDT0000</literal>,
+ <literal>OST0001</literal>, and so on.</para>
+ <note><para>The index_backup is also valid for an ldiskfs-based system,
+ that will be used when migrating data between ldiskfs-based and
+ zfs-based systems as described in <xref linkend="migrate_backends"/>.
+ </para></note>
+ </section>
+ <section xml:id="backup_fs_level.ost_mdt">
+ <title>
+ <indexterm>
+ <primary>backup</primary>
+ <secondary>OST and MDT</secondary>
+ </indexterm>Backing Up an OST or MDT</title>
+ <para>For Lustre software release 2.3 and newer with MDT file-level backup
+ support, substitute <literal>mdt</literal> for <literal>ost</literal>
+ in the instructions below.</para>
+ <orderedlist>
+ <listitem>
+ <para><emphasis role="bold">Umount the target</emphasis></para>
+ </listitem>
+ <listitem>
+ <para><emphasis role="bold">Make a mountpoint for the file system.
+ </emphasis></para>
+ <screen>[oss]# mkdir -p /mnt/ost</screen>
+ </listitem>
+ <listitem>
+ <para><emphasis role="bold">Mount the file system.</emphasis></para>
+ <para>For ldiskfs-based systems:</para>
<screen>[oss]# mount -t ldiskfs /dev/<emphasis>{ostdev}</emphasis> /mnt/ost</screen>
+ <para>For zfs-based systems:</para>
+ <orderedlist>
+ <listitem>
+ <para>Import the pool for the target if it is exported. For example:
+ <screen>[oss]# zpool import lustre-ost [-d ${ostdev_dir}]</screen>
+ </para>
+ </listitem>
+ <listitem>
+ <para>Enable the <literal>canmount</literal> property on the target
+ filesystem. For example:
+ <screen>[oss]# zfs set canmount=on ${fsname}-ost/ost</screen>
+ You also can specify the mountpoint property. By default, it will
+ be: <literal>/${fsname}-ost/ost</literal>
+ </para>
+ </listitem>
+ <listitem>
+ <para>Mount the target as 'zfs'. For example:
+ <screen>[oss]# zfs mount ${fsname}-ost/ost</screen>
+ </para>
+ </listitem>
+ </orderedlist>
</listitem>
<listitem>
<para>
</note>
</listitem>
</orderedlist>
+ </section>
</section>
- <section xml:id="dbdoclet.restore_target_filesystem">
+ <section xml:id="backup_fs_level.restore">
<title>
<indexterm>
<primary>backup</primary>
<orderedlist>
<listitem>
<para>Format the new device.</para>
- <screen>[oss]# mkfs.lustre --ost --index {<emphasis>OST index</emphasis>} {<emphasis>other options</emphasis>} /dev/<emphasis>{newdev}</emphasis></screen>
+ <screen>[oss]# mkfs.lustre --ost --index {<emphasis>OST index</emphasis>}
+--replace --fstype=${fstype} {<emphasis>other options</emphasis>} /dev/<emphasis>{newdev}</emphasis></screen>
</listitem>
<listitem>
- <para>Set the file system label.</para>
+ <para>Set the file system label (<emphasis role="bold">ldiskfs-based
+ systems only</emphasis>).</para>
<screen>[oss]# e2label {fsname}-OST{index in hex} /mnt/ost</screen>
</listitem>
<listitem>
<para>Mount the file system.</para>
+ <para>For ldiskfs-based systems:</para>
<screen>[oss]# mount -t ldiskfs /dev/<emphasis>{newdev}</emphasis> /mnt/ost</screen>
+ <para>For zfs-based systems:</para>
+ <orderedlist>
+ <listitem>
+ <para>Import the pool for the target if it is exported. For example:
+ </para>
+ <screen>[oss]# zpool import lustre-ost [-d ${ostdev_dir}]</screen>
+ </listitem>
+ <listitem>
+ <para>Enable the canmount property on the target filesystem. For
+ example:</para>
+ <screen>[oss]# zfs set canmount=on ${fsname}-ost/ost</screen>
+ <para>You also can specify the <literal>mountpoint</literal>
+ property. By default, it will be:
+ <literal>/${fsname}-ost/ost</literal></para>
+ </listitem>
+ <listitem>
+ <para>Mount the target as 'zfs'. For example:</para>
+ <screen>[oss]# zfs mount ${fsname}-ost/ost</screen>
+ </listitem>
+ </orderedlist>
</listitem>
<listitem>
<para>Change to the new file system mount point.</para>
0x0d822200000000004a8a73e500000000808a0100000000000000000000000000</screen>
</listitem>
<listitem>
- <para>Remove old OI files.</para>
- <screen>[oss]# rm -f oi.16*</screen>
+ <para>Remove old OI and LFSCK files.</para>
+ <screen>[oss]# rm -rf oi.16* lfsck_* LFSCK</screen>
</listitem>
<listitem>
<para>Remove old CATALOGS.</para>
<listitem>
<para>Unmount the new file system.</para>
<screen>[oss]# umount /mnt/ost</screen>
+ <note><para>If the restored system has a different NID from the backup
+ system, please change the NID. For detail, please refer to
+ <xref linkend="dbdoclet.changingservernid" />. For example:</para>
+ <screen>[oss]# mount -t lustre -o nosvc ${fsname}-ost/ost /mnt/ost
+[oss]# lctl replace_nids ${fsname}-OSTxxxx $new_nids
+[oss]# umount /mnt/ost</screen></note>
+ </listitem>
+ <listitem>
+ <para>Mount the target as <literal>lustre</literal>.</para>
+ <para>Usually, we will use the <literal>-o abort_recov</literal> option
+ to skip unnecessary recovery. For example:</para>
+ <screen>[oss]# mount -t lustre -o abort_recov #{fsname}-ost/ost /mnt/ost</screen>
+ <para>Lustre can detect the restore automatically when mounting the
+ target, and then trigger OI scrub to rebuild the OIs and index objects
+ asynchronously in the background. You can check the OI scrub status
+ with the following command:</para>
+ <screen>[oss]# lctl get_param -n osd-${fstype}.${fsname}-${target}.oi_scrub</screen>
</listitem>
</orderedlist>
<para condition='l23'>If the file system was used between the time the
</note>
</section>
</section>
+ <section xml:id="migrate_backends" condition="l2B">
+ <title>
+ <indexterm>
+ <primary>backup</primary>
+ <secondary>ZFS ZPL</secondary>
+ </indexterm>Migration Between ZFS and ldiskfs Target Filesystems
+ </title>
+ <para>Beginning with Lustre 2.11.0, it is possible to migrate between
+ ZFS and ldiskfs backends. For migrating OSTs, it is best to use
+ <literal>lfs find</literal>/<literal>lfs_migrate</literal> to empty out
+ an OST while the filesystem is in use and then reformat it with the new
+ fstype. For instructions on removing the OST, please see
+ <xref linkend="section_remove_ost"/>.</para>
+ <section remap="h3" xml:id="migrate_backends.zfs2ldiskfs">
+ <title>
+ <indexterm>
+ <primary>backup</primary>
+ <secondary>ZFS to ldiskfs</secondary>
+ </indexterm>Migrate from a ZFS to an ldiskfs based filesystem</title>
+ <para>The first step of the process is to make a ZFS backend backup
+ using <literal>tar</literal> as described in
+ <xref linkend="backup_fs_level"/>.</para>
+ <para>Next, restore the backup to an ldiskfs-based system as described
+ in <xref linkend="backup_fs_level.restore"/>.</para>
+ </section>
+ <section remap="h3" xml:id="migrate_backends.ldiskfs2zfs">
+ <title>
+ <indexterm>
+ <primary>backup</primary>
+ <secondary>ZFS to ldiskfs</secondary>
+ </indexterm>Migrate from an ldiskfs to a ZFS based filesystem</title>
+ <para>The first step of the process is to make an ldiskfs backend backup
+ using <literal>tar</literal> as described in
+ <xref linkend="backup_fs_level"/>.</para>
+ <para><emphasis role="strong">Caution:</emphasis>For a migration from
+ ldiskfs to zfs, it is required to enable index_backup before the
+ unmount of the target. This is an additional step for a regular
+ ldiskfs-based backup/restore and easy to be missed.</para>
+ <para>Next, restore the backup to an ldiskfs-based system as described
+ in <xref linkend="backup_fs_level.restore"/>.</para>
+ </section>
+ </section>
</chapter>
-<?xml version='1.0' encoding='UTF-8'?><chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US" xml:id="lustremaintenance">
+<?xml version='1.0' encoding='UTF-8'?><chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US" xml:id="lustremaintenance">
<title xml:id="lustremaintenance.title">Lustre Maintenance</title>
<para>Once you have the Lustre file system up and running, you can use the procedures in this section to perform these basic Lustre maintenance tasks:</para>
<itemizedlist>
<para><xref linkend="dbdoclet.50438199_54623"/></para>
</listitem>
<listitem>
- <para><xref linkend="dbdoclet.50438199_31353"/></para>
+ <para><xref linkend="dbdoclet.changingservernid"/></para>
</listitem>
<listitem>
<para><xref linkend="dbdoclet.adding_new_mdt"/></para>
</orderedlist>
<para>After the <literal>writeconf</literal> command is run, the configuration logs are re-generated as servers restart.</para>
</section>
- <section xml:id="dbdoclet.50438199_31353">
+ <section xml:id="dbdoclet.changingservernid">
<title><indexterm><primary>maintenance</primary><secondary>changing a NID</secondary></indexterm>
Changing a Server NID</title>
<para>In Lustre software release 2.3 or earlier, the <literal>tunefs.lustre
<para>If the original OST is still available, it is best to follow the
OST backup and restore procedure given in either
<xref linkend="dbdoclet.backup_device"/>, or
- <xref linkend="dbdoclet.backup_target_filesystem"/> and
- <xref linkend="dbdoclet.restore_target_filesystem"/>.</para>
+ <xref linkend="backup_fs_level"/> and
+ <xref linkend="backup_fs_level.restore"/>.</para>
<para>To replace an OST that was removed from service due to corruption
or hardware failure, the replacement OST needs to be formatted using
<literal>mkfs.lustre</literal>, and the Lustre file system configuration
linkend="configuringfailover"/>.</para>
</section>
<section xml:id="dbdoclet.50438199_62545">
- <title><indexterm><primary>maintenance</primary><secondary>separate a combined MGS/MDT</secondary></indexterm>
-Separate a combined MGS/MDT</title>
- <para>These instructions assume the MGS node will be the same as the MDS node. For instructions on how to move MGS to a different node, see <xref linkend="dbdoclet.50438199_31353"/>.</para>
- <para>These instructions are for doing the split without shutting down other servers and clients.</para>
+ <title><indexterm><primary>maintenance</primary><secondary>separate a
+ combined MGS/MDT</secondary></indexterm>
+ Separate a combined MGS/MDT</title>
+ <para>These instructions assume the MGS node will be the same as the MDS
+ node. For instructions on how to move MGS to a different node, see
+ <xref linkend="dbdoclet.changingservernid"/>.</para>
+ <para>These instructions are for doing the split without shutting down
+ other servers and clients.</para>
<orderedlist>
<listitem>
<para>Stop the MDS.</para>
git://git.whamcloud.com / doc / manual.git / commitdiff