- <para> Add a new OST by passing on the following commands, run:</para>
- <screen>oss# mkfs.lustre --fsname=spfs --mgsnode=mds16@tcp0 --ost --index=12 /dev/sda
-oss# mkdir -p /mnt/test/ost12
-oss# mount -t lustre /dev/sda /mnt/test/ost12</screen>
- </listitem>
- <listitem>
- <para> Migrate the data (possibly).</para>
- <para>The file system is quite unbalanced when new empty OSTs are added. New file creations are automatically balanced. If this is a scratch file system or files are pruned at a regular interval, then no further work may be needed.</para>
- <para>New files being created will preferentially be placed on the empty OST. As old files are deleted, they will release space on the old OST.</para>
- <para>Files existing prior to the expansion can optionally be rebalanced with an in-place copy, which can be done with a simple script. The basic method is to copy existing files to a temporary file, then move the temp file over the old one. This should not be attempted with files which are currently being written to by users or applications. This operation redistributes the stripes over the entire set of OSTs.</para>
- <para>For example, to rebalance all files within <literal>/mnt/lustre/dir</literal>, enter:</para>
- <screen>client# lfs_migrate /mnt/lustre/file</screen>
- <para>To migrate files within the <literal>/test</literal> file system on
- <literal>OST0004</literal> that are larger than 4GB in size, enter:</para>
- <screen>client# lfs find /test -obd test-OST0004 -size +4G | lfs_migrate -y</screen>
- <para>See <xref linkend="dbdoclet.50438206_42260"/> for more details.</para>
+ <para> Add a new OST by using <literal>mkfs.lustre</literal> as when
+ the filesystem was first formatted, see
+ <xref linkend="dbdoclet.format_ost" /> for details. Each new OST
+ must have a unique index number, use <literal>lctl dl</literal> to
+ see a list of all OSTs. For example, to add a new OST at index 12
+ to the <literal>testfs</literal> filesystem run following commands
+ should be run on the OSS:</para>
+ <screen>oss# mkfs.lustre --fsname=testfs --mgsnode=mds16@tcp0 --ost --index=12 /dev/sda
+oss# mkdir -p /mnt/testfs/ost12
+oss# mount -t lustre /dev/sda /mnt/testfs/ost12</screen>
+ </listitem>
+ <listitem>
+ <para>Balance OST space usage (possibly).</para>
+ <para>The file system can be quite unbalanced when new empty OSTs
+ are added to a relatively full filesystem. New file creations are
+ automatically balanced to favour the new OSTs. If this is a scratch
+ file system or files are pruned at regular intervals, then no further
+ work may be needed to balance the OST space usage as new files being
+ created will preferentially be placed on the less full OST(s). As old
+ files are deleted, they will release space on the old OST(s).</para>
+ <para>Files existing prior to the expansion can optionally be
+ rebalanced using the <literal>lfs_migrate</literal> utility.
+ This redistributes file data over the entire set of OSTs.</para>
+ <para>For example, to rebalance all files within the directory
+ <literal>/mnt/lustre/dir</literal>, enter:</para>
+ <screen>client# lfs_migrate /mnt/lustre/dir</screen>
+ <para>To migrate files within the <literal>/test</literal> file
+ system on <literal>OST0004</literal> that are larger than 4GB in
+ size to other OSTs, enter:</para>
+ <screen>client# lfs find /test --ost test-OST0004 -size +4G | lfs_migrate -y</screen>
+ <para>See <xref linkend="dbdoclet.lfs_migrate"/> for details.</para>