-<?xml version='1.0' encoding='UTF-8'?>
-<!-- This document was created with Syntext Serna Free. -->
-<chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en-US" xml:id="managinglnet">
- <info>
- <title xml:id="managinglnet.title">Managing Lustre Networking (LNET)</title>
- </info>
- <para>This chapter describes some tools for managing Lustre Networking (LNET) and includes the following sections:</para>
+<?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="managinglnet">
+ <title xml:id="managinglnet.title">Managing Lustre Networking (LNET)</title>
+ <para>This chapter describes some tools for managing Lustre networking (LNET) and includes the
+ following sections:</para>
<itemizedlist>
<listitem>
<para><xref linkend="dbdoclet.50438203_51732"/></para>
<listitem>
<para><xref linkend="dbdoclet.50438203_78227"/></para>
</listitem>
+ <listitem>
+ <para><xref linkend="managinglnet.configuringroutes"/></para>
+ </listitem>
</itemizedlist>
<section xml:id="dbdoclet.50438203_51732">
- <title>15.1 Updating the Health Status of a Peer or Router</title>
+ <title><indexterm><primary>LNET</primary><secondary>management</secondary></indexterm>
+ Updating the Health Status of a Peer or Router</title>
<para>There are two mechanisms to update the health status of a peer or a router:</para>
<itemizedlist>
<listitem>
<para>The router pinger actively checks the router health by sending pings, but LNDs only notice a dead peer when there is network traffic going on.</para>
</listitem>
<listitem>
- <para> The router pinger can bring a router from alive to dead or vice versa, but LNDs can only bring a peer down.</para>
+ <para>The router pinger can bring a router from alive to dead or vice versa, but LNDs can only bring a peer down.</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="dbdoclet.50438203_48703">
- <title>15.2 Starting and Stopping LNET</title>
- <para>Lustre automatically starts and stops LNET, but it can also be manually started in a standalone manner. This is particularly useful to verify that your networking setup is working correctly before you attempt to start Lustre.</para>
+ <title><indexterm><primary>LNET</primary><secondary>starting/stopping</secondary></indexterm>Starting and Stopping LNET</title>
+ <para>The Lustre software automatically starts and stops LNET, but it can also be manually
+ started in a standalone manner. This is particularly useful to verify that your networking
+ setup is working correctly before you attempt to start the Lustre file system.</para>
<section remap="h3">
- <title>15.2.1 Starting LNET</title>
+ <title>Starting LNET</title>
<para>To start LNET, run:</para>
<screen>$ modprobe lnet
$ lctl network up</screen>
<para>To see the list of local NIDs, run:</para>
<screen>$ lctl list_nids</screen>
- <para>This command tells you the network(s) configured to work with Lustre</para>
+ <para>This command tells you the network(s) configured to work with the Lustre file
+ system.</para>
<para>If the networks are not correctly setup, see the <literal>modules.conf</literal> "<literal>networks=</literal>" line and make sure the network layer modules are correctly installed and configured.</para>
<para>To get the best remote NID, run:</para>
- <screen>$ lctl which_nid <NID list></screen>
- <para>where <literal><NID list></literal> is the list of available NIDs.</para>
+ <screen>$ lctl which_nid <replaceable>NIDs</replaceable></screen>
+ <para>where <literal><replaceable>NIDs</replaceable></literal> is the list of available NIDs.</para>
<para>This command takes the "best" NID from a list of the NIDs of a remote host. The "best" NID is the one that the local node uses when trying to communicate with the remote node.</para>
<section remap="h4">
- <title>15.2.1.1 Starting Clients</title>
+ <title>Starting Clients</title>
<para>To start a TCP client, run:</para>
<screen>mount -t lustre mdsnode:/mdsA/client /mnt/lustre/</screen>
<para>To start an Elan client, run:</para>
</section>
</section>
<section remap="h3">
- <title>15.2.2 Stopping LNET</title>
- <para>Before the LNET modules can be removed, LNET references must be removed. In general, these references are removed automatically when Lustre is shut down, but for standalone routers, an explicit step is needed to stop LNET. Run:</para>
+ <title>Stopping LNET</title>
+ <para>Before the LNET modules can be removed, LNET references must be removed. In general,
+ these references are removed automatically when the Lustre file system is shut down, but for
+ standalone routers, an explicit step is needed to stop LNET. Run:</para>
<screen>lctl network unconfigure</screen>
<note>
- <para>
-Attempting to remove Lustre modules prior to stopping the network may result in a crash or an LNET hang. if this occurs, the node must be rebooted (in most cases). Make sure that the Lustre network and Lustre are stopped prior to unloading the modules. Be extremely careful using rmmod -f.</para>
+ <para>Attempting to remove Lustre modules prior to stopping the network may result in a
+ crash or an LNET hang. If this occurs, the node must be rebooted (in most cases). Make
+ sure that the Lustre network and Lustre file system are stopped prior to unloading the
+ modules. Be extremely careful using <literal>rmmod -f</literal>.</para>
</note>
<para>To unconfigure the LNET network, run:</para>
- <screen>modprobe -r <any lnd and the lnet modules>
-</screen>
+ <screen>modprobe -r <replaceable>lnd_and_lnet_modules</replaceable></screen>
<note>
<para>
To remove all Lustre modules, run:</para>
- <para><literal>$ lctl modules | awk '{print $2}' | xargs rmmod</literal></para>
+ <para><literal>$ lustre_rmmod</literal></para>
</note>
</section>
</section>
<section xml:id="dbdoclet.50438203_82542">
- <title>15.3 Multi-Rail Configurations with LNET</title>
+ <title><indexterm><primary>LNET</primary><secondary>multi-rail configuration</secondary></indexterm>Multi-Rail Configurations with LNET</title>
<para>To aggregate bandwidth across both rails of a dual-rail IB cluster (o2iblnd) <footnote>
<para>Multi-rail configurations are only supported by o2iblnd; other IB LNDs do not support multiple interfaces.</para>
</footnote> using LNET, consider these points:</para>
<para>LNET can work with multiple rails, however, it does not load balance across them. The actual rail used for any communication is determined by the peer NID.</para>
</listitem>
<listitem>
- <para>Multi-rail LNET configurations do not provide an additional level of network fault tolerance. The configurations described below are for bandwidth aggregation only. Network interface failover is planned as an upcoming Lustre feature.</para>
+ <para>Multi-rail LNET configurations do not provide an additional level of network fault
+ tolerance. The configurations described below are for bandwidth aggregation only. </para>
</listitem>
<listitem>
<para>A Lustre node always uses the same local NID to communicate with a given peer NID. The criteria used to determine the local NID are:</para>
<itemizedlist>
+ <listitem>
+ <para condition='l25'>Lowest route priority number (lower number, higher priority).</para>
+ </listitem>
<listitem>
- <para> Fewest hops (to minimize routing), and</para>
+ <para>Fewest hops (to minimize routing), and</para>
</listitem>
<listitem>
- <para> Appears first in the "<literal>networks</literal>" or "<literal>ip2nets</literal>" LNET configuration strings</para>
+ <para>Appears first in the "<literal>networks</literal>" or "<literal>ip2nets</literal>" LNET configuration strings</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
</section>
<section xml:id="dbdoclet.50438203_78227">
- <title>15.4 Load Balancing with InfiniBand</title>
- <para>A Lustre file system contains OSSs with two InfiniBand HCAs. Lustre clients have only one InfiniBand HCA using OFED Infiniband ''o2ib'' drivers. Load balancing between the HCAs on the OSS is accomplished through LNET.</para>
+ <title><indexterm>
+ <primary>LNET</primary>
+ <secondary>InfiniBand load balancing</secondary>
+ </indexterm>Load Balancing with an InfiniBand<superscript>*</superscript> Network</title>
+ <para>A Lustre file system contains OSSs with two InfiniBand HCAs. Lustre clients have only one
+ InfiniBand HCA using OFED-based Infiniband ''o2ib'' drivers. Load
+ balancing between the HCAs on the OSS is accomplished through LNET.</para>
<section remap="h3">
- <title>15.4.1 Setting Up <literal>modprobe.conf</literal> for Load Balancing</title>
+ <title><indexterm><primary>LNET</primary><secondary>lustre.conf</secondary></indexterm>Setting Up <literal>lustre.conf</literal> for Load Balancing</title>
<para>To configure LNET for load balancing on clients and servers:</para>
<orderedlist>
<listitem>
- <para><emphasis role="bold">Set the <literal>modprobe.conf</literal> options.</emphasis></para>
- <para>Depending on your configuration, set modprobe.conf options as follows:</para>
+ <para>Set the <literal>lustre.conf</literal> options.</para>
+ <para>Depending on your configuration, set <literal>lustre.conf</literal> options as follows:</para>
<itemizedlist>
<listitem>
- <para> Dual HCA OSS server</para>
+ <para>Dual HCA OSS server</para>
</listitem>
</itemizedlist>
- <screen>options lnet networks="o2ib0(ib0),o2ib1(ib1) 192.168.10.1.[101-102] </screen>
+ <screen>options lnet networks="o2ib0(ib0),o2ib1(ib1)"</screen>
<itemizedlist>
<listitem>
- <para> Client with the odd IP address</para>
+ <para>Client with the odd IP address</para>
</listitem>
</itemizedlist>
- <screen>options lnet networks=o2ib0(ib0) 192.168.10.[103-253/2] </screen>
+ <screen>options lnet ip2nets="o2ib0(ib0) 192.168.10.[103-253/2]"</screen>
<itemizedlist>
<listitem>
- <para> Client with the even IP address</para>
+ <para>Client with the even IP address</para>
</listitem>
</itemizedlist>
- <screen>options lnet networks=o2ib1(ib0) 192.168.10.[102-254/2]
-</screen>
+ <screen>options lnet ip2nets="o2ib1(ib0) 192.168.10.[102-254/2]"</screen>
</listitem>
<listitem>
- <para><emphasis role="bold">Run the modprobe lnet command and create a combined MGS/MDT file system.</emphasis></para>
- <para>The following commands create the MGS/MDT file system and mount the servers (MGS/MDT and OSS).</para>
+ <para>Run the modprobe lnet command and create a combined MGS/MDT file system.</para>
+ <para>The following commands create an MGS/MDT or OST file system and mount the targets on the servers.</para>
<screen>modprobe lnet
-$ mkfs.lustre --fsname lustre --mgs --mdt <block device name>
-$ mkdir -p <mount point>
-$ mount -t lustre <block device> <mount point>
-$ mount -t lustre <block device> <mount point>
-$ mkfs.lustre --fsname lustre --mgs --mdt <block device name>
-$ mkdir -p <mount point>
-$ mount -t lustre <block device> <mount point>
-$ mount -t lustre <block device> <mount point> </screen>
+# mkfs.lustre --fsname lustre --mgs --mdt <replaceable>/dev/mdt_device</replaceable>
+# mkdir -p <replaceable>/mount_point</replaceable>
+# mount -t lustre /dev/<replaceable>mdt_device</replaceable> <replaceable>/mount_point</replaceable></screen>
<para>For example:</para>
<screen>modprobe lnet
-$ mkfs.lustre --fsname lustre --mdt --mgs /dev/sda
-$ mkdir -p /mnt/test/mdt
-$ mount -t lustre /dev/sda /mnt/test/mdt
-$ mount -t lustre mgs@o2ib0:/lustre /mnt/mdt
-$ mkfs.lustre --fsname lustre --ost --mgsnode=mds@o2ib0 /dev/sda
-$ mkdir -p /mnt/test/mdt
-$ mount -t lustre /dev/sda /mnt/test/ost
-$ mount -t lustre mgs@o2ib0:/lustre /mnt/ost</screen>
+mds# mkfs.lustre --fsname lustre --mdt --mgs /dev/sda
+mds# mkdir -p /mnt/test/mdt
+mds# mount -t lustre /dev/sda /mnt/test/mdt
+mds# mount -t lustre mgs@o2ib0:/lustre /mnt/mdt
+oss# mkfs.lustre --fsname lustre --mgsnode=mds@o2ib0 --ost --index=0 /dev/sda
+oss# mkdir -p /mnt/test/mdt
+oss# mount -t lustre /dev/sda /mnt/test/ost
+oss# mount -t lustre mgs@o2ib0:/lustre /mnt/ost0</screen>
</listitem>
<listitem>
- <para><emphasis role="bold">Mount the clients.</emphasis></para>
- <screen>mount -t lustre <MGS node>:/<fsname> <mount point></screen>
+ <para>Mount the clients.</para>
+ <screen>client# mount -t lustre <replaceable>mgs_node</replaceable>:/<replaceable>fsname</replaceable> <replaceable>/mount_point</replaceable></screen>
<para>This example shows an IB client being mounted.</para>
- <screen>mount -t lustre
+ <screen>client# mount -t lustre
192.168.10.101@o2ib0,192.168.10.102@o2ib1:/mds/client /mnt/lustre</screen>
</listitem>
</orderedlist>
- <para>As an example, consider a two-rail IB cluster running the OFA stack (OFED) with these IPoIB address assignments.</para>
+ <para>As an example, consider a two-rail IB cluster running the OFED stack with these IPoIB
+ address assignments.</para>
<screen> ib0 ib1
Servers 192.168.0.* 192.168.1.*
Clients 192.168.[2-127].* 192.168.[128-253].*</screen>
<para>You could create these configurations:</para>
<itemizedlist>
<listitem>
- <para>A cluster with more clients than servers. The fact that an individual client cannot get two rails of bandwidth is unimportant because the servers are the actual bottleneck.</para>
+ <para>A cluster with more clients than servers. The fact that an individual client cannot get two rails of bandwidth is unimportant because the servers are typically the actual bottleneck.</para>
</listitem>
</itemizedlist>
<screen>ip2nets="o2ib0(ib0), o2ib1(ib1) 192.168.[0-1].* \
<para>This configuration gives every server two NIDs, one on each network, and statically load-balances clients between the rails.</para>
<itemizedlist>
<listitem>
- <para> A single client that must get two rails of bandwidth, and it does not matter if the maximum aggregate bandwidth is only (# servers) * (1 rail).</para>
+ <para>A single client that must get two rails of bandwidth, and it does not matter if the maximum aggregate bandwidth is only (# servers) * (1 rail).</para>
</listitem>
</itemizedlist>
<screen>ip2nets=" o2ib0(ib0) 192.168.[0-1].[0-252/2] \
<para>This configuration gives every server a single NID on one rail or the other. Clients have a NID on both rails.</para>
<itemizedlist>
<listitem>
- <para> All clients and all servers must get two rails of bandwidth.</para>
+ <para>All clients and all servers must get two rails of bandwidth.</para>
</listitem>
</itemizedlist>
<screen>ip2nets=†o2ib0(ib0),o2ib2(ib1) 192.168.[0-1].[0-252/2] \
o2ib0(ib0),o2ib3(ib1) 192.168.[2-253].[0-252/2) \
#even clients;\
o2ib1(ib0),o2ib2(ib1) 192.168.[2-253].[1-253/2) \
-#odd clients"
-</screen>
- <para>This configuration includes two additional proxy o2ib networks to work around Lustre's simplistic NID selection algorithm. It connects "even" clients to "even" servers with <literal>o2ib0</literal> on <literal>rail0</literal>, and "odd" servers with <literal>o2ib3</literal> on <literal>rail1</literal>. Similarly, it connects "odd" clients to "odd" servers with <literal>o2ib1</literal> on <literal>rail0</literal>, and "even" servers with <literal>o2ib2</literal> on <literal>rail1</literal>.</para>
+#odd clients"</screen>
+ <para>This configuration includes two additional proxy o2ib networks to work around the
+ simplistic NID selection algorithm in the Lustre software. It connects "even"
+ clients to "even" servers with <literal>o2ib0</literal> on
+ <literal>rail0</literal>, and "odd" servers with <literal>o2ib3</literal> on
+ <literal>rail1</literal>. Similarly, it connects "odd" clients to
+ "odd" servers with <literal>o2ib1</literal> on <literal>rail0</literal>, and
+ "even" servers with <literal>o2ib2</literal> on <literal>rail1</literal>.</para>
+ </section>
+ </section>
+ <section xml:id="managinglnet.configuringroutes" condition='l24'>
+ <title><indexterm><primary>LNET</primary></indexterm>Dynamically Configuring LNET Routes</title>
+ <para>Two scripts are provided: <literal>lustre/scripts/lustre_routes_config</literal> and <literal>lustre/scripts/lustre_routes_conversion</literal>.</para>
+ <para><literal>lustre_routes_config</literal> sets or cleans up LNET routes from the specified config file. <literal>/etc/sysconfig/lustre_routes.conf</literal> file can be used to automatically configure routes on LNET startup. </para>
+ <para><literal>lustre_routes_conversion</literal> converts a legacy routes configuration file to the new syntax, which is parsed by <literal>lustre_routes_config</literal>.</para>
+ <section remap="h3">
+ <title><indexterm><primary>LNET</primary></indexterm><literal>lustre_routes_config</literal></title>
+ <para><literal>lustre_routes_config</literal> usage is as follows</para>
+ <screen><literal>lustre_routes_config [--setup|--cleanup|--dry-run|--verbose] <replaceable>config_file</replaceable></literal>
+ --setup: configure routes listed in config_file
+ --cleanup: unconfigure routes listed in config_file
+ --dry-run: echo commands to be run, but do not execute them
+ --verbose: echo commands before they are executed </screen>
+ <para> The format of the file which is passed into the script is as follows: </para>
+ <para><literal><replaceable>network</replaceable>: { gateway: <replaceable>gateway</replaceable>@<replaceable>exit_network</replaceable> [hop: <replaceable>hop</replaceable>] [priority: <replaceable>priority</replaceable>] }</literal></para>
+ <para> An LNET router is identified when its local NID appears within the list of routes. However, this can not be achieved by the use of this script, since the script only adds extra routes after the router is identified. To ensure that a router is identified correctly, make sure to add its local NID in the routes parameter in the modprobe lustre configuration file. See <xref linkend='dbdoclet.50438293_15350'/>.</para>
+ </section>
+ <section remap="h3">
+ <title><indexterm><primary>LNET</primary></indexterm><literal>lustre_routes_conversion</literal></title>
+ <para><literal>lustre_routes_conversion</literal> usage is as follows:</para>
+ <screen><literal>lustre_routes_conversion <replaceable>legacy_file</replaceable> <replaceable>new_file</replaceable></literal></screen>
+ <para><literal>lustre_routes_conversion</literal> takes as a first parameter a file with routes configured as follows:</para>
+ <para><literal><replaceable>network</replaceable> [<replaceable>hop</replaceable>] <replaceable>gateway</replaceable>@<replaceable>exit network</replaceable>[:<replaceable>priority</replaceable>];</literal></para>
+ <para>The script then converts each routes entry in the provided file to:</para>
+ <para><literal><replaceable>network</replaceable>: { gateway: <replaceable>gateway</replaceable>@<replaceable>exit network</replaceable> [hop: <replaceable>hop</replaceable>] [priority: <replaceable>priority</replaceable>] }</literal></para>
+ <para>and appends each converted entry to the output file passed in as the second parameter to the script.</para>
+ </section>
+ <section remap="h3">
+ <title><indexterm><primary>LNET</primary></indexterm><literal>Route Configuration Examples</literal></title>
+ <para>Below is an example of a legacy LNET route configuration. A legacy configuration file can have multiple entries.</para>
+ <screen><literal>tcp1 10.1.1.2@tcp0:1;
+tcp2 10.1.1.3@tcp0:2;
+tcp3 10.1.1.4@tcp0;</literal></screen>
+ <para>Below is an example of the converted LNET route configuration. The following would be the result of the <literal>lustre_routes_conversion</literal> script, when run on the above legacy entries.</para>
+ <screen><literal>tcp1: { gateway: 10.1.1.2@tcp0 priority: 1 }
+tcp2: { gateway: 10.1.1.2@tcp0 priority: 2 }
+tcp1: { gateway: 10.1.1.4@tcp0 }</literal></screen>
</section>
</section>
</chapter>
git://git.whamcloud.com / doc / manual.git / blobdiff