- <para>If there is a need to migrate the file data from the current
- OST(s) to new OSTs, the data must be migrated (copied) to the new
- location. The simplest way to do this is to use the
- <literal>lfs_migrate</literal> command (see
- <xref linkend="dbdoclet.50438206_42260" />). However, the steps for
- migrating a file by hand are also shown here for reference.</para>
- <orderedlist>
- <listitem>
- <para>Identify the file(s) to be moved.</para>
- <para>In the example below, the object information portion of the output from the
- <literal>lfs getstripe</literal> command below shows that the
- <literal>test_2</literal>file is located entirely on OST0002:</para>
- <screen>
-client# lfs getstripe /mnt/testfs/test_2
-/mnt/testfs/test_2
-obdidx objid objid group
- 2 8 0x8 0
-</screen>
- </listitem>
- <listitem>
- <para>To move the data, create a copy and remove the original:</para>
- <screen>
-client# cp -a /mnt/testfs/test_2 /mnt/testfs/test_2.tmp
-client# mv /mnt/testfs/test_2.tmp /mnt/testfs/test_2
-</screen>
- </listitem>
- <listitem>
- <para>If the space usage of OSTs is severely imbalanced, it is
- possible to find and migrate large files from their current location
- onto OSTs that have more space, one could run:</para>
- <screen>
-client# lfs find --ost
-<replaceable>ost_name</replaceable> -size +1G | lfs_migrate -y
-</screen>
- </listitem>
- <listitem>
- <para>Check the file system balance.</para>
- <para>The
- <literal>lfs df</literal> output in the example below shows a more
- balanced system compared to the
- <literal>lfs df</literal> output in the example in
- <xref linkend="dbdoclet.50438211_17536" />.</para>
- <screen>
-client# lfs df -h
-UUID bytes Used Available Use% \
- Mounted on
-testfs-MDT0000_UUID 4.4G 214.5M 3.9G 4% \
- /mnt/testfs[MDT:0]
-testfs-OST0000_UUID 2.0G 1.3G 598.1M 65% \
- /mnt/testfs[OST:0]
-testfs-OST0001_UUID 2.0G 1.3G 594.1M 65% \
- /mnt/testfs[OST:1]
-testfs-OST0002_UUID 2.0G 913.4M 1000.0M 45% \
- /mnt/testfs[OST:2]
-testfs-OST0003_UUID 2.0G 1.3G 602.1M 65% \
- /mnt/testfs[OST:3]
-testfs-OST0004_UUID 2.0G 1.3G 606.1M 64% \
- /mnt/testfs[OST:4]
-testfs-OST0005_UUID 2.0G 1.3G 610.1M 64% \
- /mnt/testfs[OST:5]
-
-filesystem summary: 11.8G 7.3G 3.9G 61% \
-/mnt/testfs
-</screen>
- </listitem>
- </orderedlist>
+ <para>If there is a need to migrate the file <emphasis>data</emphasis>
+ from the current OST(s) to new OST(s), the data must be migrated (copied)
+ to the new location. The simplest way to do this is to use the
+ <literal>lfs_migrate</literal> command, see
+ <xref linkend="dbdoclet.lfs_migrate" />.</para>