Installing the Lustre Software

The process of installing Lustre software is straightforward, but there are several options that need to be considered. These options are driven by the fact that Lustre is implemented as kernel modules, and has dependencies on other kernel modules in order to operate correctly. Specifically, Lustre is layered on top of block storage devices formatted either as LDISKFS (a variant of EXT4) or ZFS, and Lustre's RDMA networking driver leverages interfaces to the device drivers for RDMA capable fabrics such as InfiniBand and Intel Omni-path Architecture (OPA).

This article demonstrates how to install Lustre with LDISKFS and/or ZFS support, but will not specifically cover third party device drivers such as OFED, since there are a number of variations on implementation depending on the hardware vendor.

For more comprehensive coverage of third party network driver support, refer to the Compiling Lustre article, which will show how to create these packages. Once created, the process for installing these customised packages is very similar to the process described here.

Note: it is recommended that the host operating system is always installed with the latest kernel release supported by the operating system vendor. This ensures that the kernel is protected against known security vulnerabilities and has the latest bug fixes. The Lustre developers work to ensure that Lustre remains compatible across operating system kernel updates for supported platforms. For the latest information on compatibility for Linux kernels, refer to the Lustre ChangeLog file.

Lustre and OpenZFS
OpenZFS support for Lustre Object Storage Devices (OSDs) was introduced in Lustre version 2.4. ZFS is an integrated file system and storage management platform with strong data integrity and volume management features that complement the performance and scalability of Lustre.

The Linux kernel does not require Lustre-specific patches when using ZFS as the storage platform for Lustre servers. The ZFS kernel modules will be compiled against the kernel currently running on the target host.

The installation process for ZFS-based builds is more complex than for LDISKFS due to complications arising from an incompatibility in the distribution clauses of the licenses for the Linux kernel and OpenZFS. Linux is distributed under the terms of the GPLv2, while OpenZFS is governed by the CDDL. Both GPL and CDDL are free software open source licenses, but certain clauses create an incompatibility that prevents their distribution together in binary form. See the note at the end of this section for information on the license incompatibility.

Fortunately, by making use of a software distribution framework called Dynamic Kernel Modules Support (DKMS), OpenZFS can be packaged in a format that is easy for system integrators and operators to build and install. DKMS also ensures that any kernel modules are automatically recompiled if the kernel is updated.

The documentation here will focus on using DKMS. Refer to the Compiling Lustre article for information on creating binary kernel module packages for ZFS on Linux.

For the DKMS mechanism to work, compiler tools and some additional libraries will be needed on each OpenZFS-based Lustre server. DKMS recompiles DKMS-enabled kernel modules whenever a kernel update is installed, which means the compiler tool-chain must be present on all systems using the OpenZFS file system. The  and   packages for any new Linux kernel are also required.

Note: The CDDL (the license of OpenZFS) and GPLv2 (the license of Linux) are considered incompatible by the FSF (the authors of the GPL; see https://www.gnu.org/licenses/license-list.html#CDDL), but does not prohibit end users from using OpenZFS with Linux together in ways that don’t invoke that incompatibility. The Lustre community does not distribute compiled binaries of OpenZFS kernel modules for Linux. Consider seeking legal advice for any activities that might be considered “distribution” under GPLv2.

Using YUM to Manage Local Software Provisioning
To streamline the installation process, the Lustre packages can be copied to an HTTP server on the network and incorporated into local YUM repositories.

Using YUM repositories simplifies the distribution of software packages to computers, aiding provisioning and configuration automation, and simplifying tasks such as auditing and updating.

The following instructions can be used to help establish a web server as a YUM repository host for the Lustre packages. The examples make use of the default directory structure for an Apache HTTP server on RHEL / CentOS 7. NGINX and other web servers may use different directory structures to store content.

Note: The installation processes used in this article assume that there is a YUM repo definition for the Lustre packages configured on the machines where Lustre will be installed.

 Create a temporary YUM repository definition. This will be used to assist with the initial acquisition of Lustre and related packages.

 cat >/tmp/lustre-repo.conf <<\__EOF [lustre-server-2.10.0] name=lustre-server baseurl=https://downloads.hpdd.intel.com/public/lustre/lustre-2.10.0/el7/server gpgcheck=0
 * 1) exclude=*debuginfo*

[lustre-client-2.10.0] name=lustre-client baseurl=https://downloads.hpdd.intel.com/public/lustre/lustre-2.10.0/el7/client gpgcheck=0
 * 1) exclude=*debuginfo*

[e2fsprogs-wc] name=e2fsprogs-wc baseurl=https://downloads.hpdd.intel.com/public/e2fsprogs/latest/el7 gpgcheck=0 __EOF
 * 1) exclude=*debuginfo*

Note: The above example references the Lustre version explicitly. To always pull the latest version, replace  with   in the URLs and remove the version numbers from the repository section header. Always pull in the latest  package unless directed otherwise.

To cut down on the size of the download when testing, uncomment the exclude lines. This will omit the download of the debuginfo packages, which can be large. Nevertheless, it is generally a good idea to pull in these files as well in order that they be readily available to aid debugging. 

Use the  command (distributed in the   package) to download mirrors of the Lustre repositories to the manager server:

 mkdir -p /var/lib/www/html/repo cd /var/www/html/repo reposync -c /tmp/lustre-repo.conf -n \ -r lustre-server-2.10.0 \ -r lustre-client-2.10.0 \ -r e2fsprogs-wc  Create the repository metadata:

 cd /var/www/html/repo for i in e2fsprogs-wc lustre-client-2.10.0 lustre-server-2.10.0; do (cd $i && createrepo .) done 

Create a YUM repository definition file. The following script creates a file containing repository definitions for the Lustre packages, and stores it in the web server static content directory. This makes it easy to distribute to the Lustre servers and clients.

Review the content and adjust according to the requirements of the target environment. Run the script on the web server host:

 hn=`hostname --fqdn` cat >/var/www/html/lustre-2.10.0.repo <<__EOF [lustre-server-2.10.0] name=lustre-server baseurl=https://$hn/repo/lustre-server-2.10.0 enabled=0 gpgcheck=0 proxy=_none_

[lustre-client-2.10.0] name=lustre-client baseurl=https://$hn/repo/lustre-client-2.10.0 enabled=0 gpgcheck=0

[e2fsprogs-wc] name=e2fsprogs-wc baseurl=https://$hn/repo/e2fsprogs-wc enabled=0 gpgcheck=0 __EOF

Make sure that the  variable matches the host name that will be used by the Lustre servers and clients to access the YUM web server.

The use of the version numbers for the repository definitions is a matter of preference, and can be altered. As new versions of Lustre are released, these version numbers will, naturally, need to be changed.  Apply any configuration changes that may be necessary for the web server to incorporate the new bundle directories. The configuration may need to be reloaded, or the web service restarted when done.  Copy the Lustre repo definition file onto each of the Lustre servers and clients, in the directory. Utilities like  and   can be used to retrieve the file from the web server as part of a configuration management system rule/promise or during system provisioning. </li> </ol>

Lustre Server Software Installation
Select one of the procedures described in the following sections and install the Lustre software on each of the machines that will be used as Lustre servers.

Lustre Servers with Both LDISKFS and ZFS OSD Support
Note: This configuration provides the widest range of compatibility with the different storage types, mostly useful for migration purposes or for broad compatibility with software such as Manager for Lustre.

<ol> Install the Lustre  distribution:

<pre style="overflow-x:auto;"> yum --nogpgcheck --disablerepo=* --enablerepo=e2fsprogs-wc \ install e2fsprogs </li>

Follow the instructions from the ZFS on Linux project to install the ZFS YUM repository definition. Use the DKMS package repository (the default). For example: <pre style="overflow-x:auto;"> yum -y install \ http://download.zfsonlinux.org/epel/zfs-release.el7_3.noarch.rpm </li>

Install the Lustre-patched kernel packages. Ensure that the Lustre repository is picked for the kernel packages, by disabling the OS repos:

<pre style="overflow-x:auto;"> yum --nogpgcheck --disablerepo=base,extras,updates \ --enablerepo=lustre-server-2.10.0 install \ kernel \ kernel-devel \ kernel-headers \ kernel-tools \ kernel-tools-libs \ kernel-tools-libs-devel </li>

Generate a persistent hostid on the machine, if one does not already exist. This is needed to help protect ZFS zpools against simultaneous imports on multiple servers. For example:

hid=`[ -f /etc/hostid ] && od -An -tx /etc/hostid|sed 's/ //g'` [ "$hid" = `hostid` ] || genhostid </li>

Reboot the node. <pre style="overflow-x:auto;"> reboot </li>

Install Lustre, and the LDISKFS and ZFS kmod packages:

<pre style="overflow-x:auto;"> yum --nogpgcheck --enablerepo=lustre-server-2.10.0 install \ lustre-dkms \ zfs \ kmod-lustre-osd-ldiskfs \ lustre-osd-ldiskfs-mount \ lustre-osd-zfs-mount \ lustre \ lustre-resource-agents </li>

Load the Lustre and ZFS kernel modules to verify that the software has installed correctly:

<pre style="overflow-x:auto;"> modprobe -v zfs modprobe -v lustre </li>

Before continuing to configuration of LNet, unload the Lustre modules from the kernel: <pre style="overflow-x:auto;"> lustre_rmmod </li> </ol>

Lustre Servers with ZFS OSD Support
<ol> Follow the instructions from the ZFS on Linux project to install the ZFS YUM repository definition. Use the DKMS package repository (the default). For example: <pre style="overflow-x:auto;"> yum -y install \ http://download.zfsonlinux.org/epel/zfs-release.el7_3.noarch.rpm </li>

Install the kernel packages that match the latest supported version for the Lustre release:

<pre style="overflow-x:auto;"> yum install \ kernel \ kernel-devel \ kernel-headers \ kernel-tools \ kernel-tools-libs \ kernel-tools-libs-devel

It may be necessary to specify the kernel package version number in order to ensure that a kernel that is compatible with Lustre is installed. For example, Lustre 2.10.0 has support for RHEL kernel 3.10.0-514.21.1.el7:

<pre style="overflow-x:auto;"> yum install \ kernel-3.10.0-514.21.1.el7 \ kernel-devel-3.10.0-514.21.1.el7 \ kernel-headers-3.10.0-514.21.1.el7 \ kernel-tools-3.10.0-514.21.1.el7 \ kernel-tools-libs-3.10.0-514.21.1.el7 \ kernel-tools-libs-devel-3.10.0-514.21.1.el7

Refer to the Lustre ChangeLog for the list of supported kernels. </li>

Generate a persistent hostid on the machine, if one does not already exist. This is needed to help protect ZFS zpools against simultaneous imports on multiple servers. For example:

hid=`[ -f /etc/hostid ] && od -An -tx /etc/hostid|sed 's/ //g'` [ "$hid" = `hostid` ] || genhostid </li>

Reboot the node.

<pre style="overflow-x:auto;"> reboot </li>

Install the packages for Lustre and ZFS:

<pre style="overflow-x:auto;"> yum --nogpgcheck --enablerepo=lustre-server-2.10.0 install \ lustre-dkms \ zfs \ lustre-osd-zfs-mount \ lustre \ lustre-resource-agents </li>

Load the Lustre and ZFS kernel modules to verify that the software has installed correctly:

<pre style="overflow-x:auto;"> modprobe -v zfs modprobe -v lustre </li>

Upon verification, unload the Lustre modules from the kernel:

<pre style="overflow-x:auto;"> lustre_rmmod </li> </ol>

Lustre Servers with LDISKFS OSD Support
<ol> Install the Lustre  distribution:

<pre style="overflow-x:auto;"> yum --nogpgcheck --disablerepo=* --enablerepo=e2fsprogs-wc \ install e2fsprogs </li>

<li>Install the Lustre-patched kernel packages. Ensure that the Lustre repository is picked for the kernel packages, by disabling the OS repos:

<pre style="overflow-x:auto;"> yum --nogpgcheck --disablerepo=base,extras,updates \ --enablerepo=lustre-server-2.10.0 install \ kernel \ kernel-devel \ kernel-headers \ kernel-tools \ kernel-tools-libs \ kernel-tools-libs-devel </li>

<li>Reboot the node:

<pre style="overflow-x:auto;"> reboot </li>

<li>Install the LDISKFS  and other Lustre packages:

<pre style="overflow-x:auto;"> yum --nogpgcheck --enablerepo=lustre-server-2.10.0 install \ kmod-lustre \ kmod-lustre-osd-ldiskfs \ lustre-osd-ldiskfs-mount \ lustre \ lustre-resource-agents </li>

<li>Load the Lustre kernel modules to verify that the software has installed correctly:

<pre style="overflow-x:auto;"> modprobe -v lustre </li>

<li>Upon verification, unload the Lustre modules from the kernel:

<pre style="overflow-x:auto;"> lustre_rmmod </li> </ol>

Lustre Client Software Installation
The Lustre client software comprises a package containing the kernel modules and separate packages for user-space tools used to manage the client software. The Lustre clients do not require a "Lustre-patched" kernel, which simplifies installation.

Execute the following steps on each machine in that will use the Lustre client:

<ol> <li>Install the kernel packages that match the latest supported version for the Lustre release:

<pre style="overflow-x:auto;"> yum install \ kernel \ kernel-devel \ kernel-headers \ kernel-tools \ kernel-tools-libs \ kernel-tools-libs-devel

It may be necessary to specify the kernel package version number in order to ensure that a kernel that is compatible with Lustre is installed. For example, Lustre 2.10.0 has support for RHEL kernel 3.10.0-514.21.1.el7:

<pre style="overflow-x:auto;"> yum install \ kernel-3.10.0-514.21.1.el7 \ kernel-devel-3.10.0-514.21.1.el7 \ kernel-headers-3.10.0-514.21.1.el7 \ kernel-tools-3.10.0-514.21.1.el7 \ kernel-tools-libs-3.10.0-514.21.1.el7 \ kernel-tools-libs-devel-3.10.0-514.21.1.el7

Refer to the Lustre ChangeLog for the list of supported kernels. </li>

<li>Install the Lustre client packages:

<pre style="overflow-x:auto;"> yum --nogpgcheck --enablerepo=lustre-client-2.10.0 install \ kmod-lustre-client \ lustre </li>

<li>Load the Lustre and ZFS kernel modules to verify that the software has installed correctly:

<pre style="overflow-x:auto;"> modprobe -v lustre </li>

<li>Upon verification, unload the Lustre modules from the kernel:

<pre style="overflow-x:auto;"> lustre_rmmod </li> </ol>