SUSE Linux Enterprise High Availability Extension 12 SP3

Release Notes

SUSE Linux Enterprise High Availability Extension is a suite of clustering technologies that enable enterprises to implement highly available Linux clusters and eliminate single points of failure. This document gives an overview of features of SUSE Linux Enterprise High Availability Extension and their limitations. Some sections do not apply to a particular architecture or product, this is explicitly marked.

Manuals can be found in the docu directory of the installation media, or in the directory /usr/share/doc/ on the installed system (if installed).

Product to be released: September 2017

Publication Date: 2017-07-12, Version: 12.3.20170706

1 SUSE Linux Enterprise High Availability Extension

SUSE Linux Enterprise High Availability Extension is an affordable, integrated suite of robust open source clustering technologies that enable enterprises to implement highly available Linux clusters and eliminate single points of failure.

Used with SUSE Linux Enterprise Server, it helps firms maintain business continuity, protect data integrity, and reduce unplanned downtime for their mission-critical Linux workloads.

SUSE Linux Enterprise High Availability Extension provides all of the essential monitoring, messaging, and cluster resource management functionality of proprietary third-party solutions, but at a more affordable price, making it accessible to a wider range of enterprises.

It is optimized to work with SUSE Linux Enterprise Server, and its tight integration ensures customers have the most robust, secure, and up to date high availability solution. Based on an innovative, highly flexible policy engine, it supports a wide range of clustering scenarios.

With static or stateless content, the High Availability cluster can be used without a cluster file system. This includes web-services with static content as well as printing systems or communication systems like proxies that do not need to recover data.

Finally, its open source license minimizes the risk of vendor lock-in, and its adherence to open standards encourages interoperability with industry standard tools and technologies.

2 What Is New?

Cluster File System

GFS2 cluster file system with read/write support, to complement the SUSE recommended OCFS2 cluster file system.

Load balancer

HAProxy as layer 4 load balancer added, to complement the Linux virtual server load balancer.

History Explorer

Hawk history explorer now includes off-line analysis capabilities.

Resource Agents

Resource agents got multiple updates, including a resource agent to handle SCSI reservations

Make sure to also review the release notes for the base product, SUSE Linux Enterprise Server 12 SP3 which are published at

To find out what is new in the Geo clustering option for the SUSE Linux Enterprise High Availability Extension 12 SP3, see

3 Cluster

3.1 Support for Watchdog-only Fencing Using SBD

For some scenarios that do not involve shared storage, relying on cluster quorum together with a hardware watchdog device for fencing is sufficient as a fencing mechanism.

SBD can function in a disk-less mode which relies solely on the hardware watchdog device for detecting and recovering from node failure. This method depends on cluster quorum, and thus needs a minimum of three nodes in the cluster.

When using this fencing method, recovery of a fenced node takes at least as long as the watchdog timeout.

4 High-Availability Tools

4.1 Bug Fixes in Corosync 2.4.x Have Been Backported to 2.3.6

There are some issues in Corosync 2.3.5 which were fixed in later versions. The current Corosync release series is 2.4 which, however, has very different ABI.

In SLE HA 12 SP3, we wanted to avoid a large Corosync ABI change. Therefore, Corosync has been updated to version 2.3.6 and patches from version 2.4.2 have been backported.

4.2 Hawk: Detection of Unexpected DRBD Resource Status

In previous versions of SLE HA, if a DRBD resource had lost connection to its peer or was in standalone mode for any other reason, the DRBD resource would still run OK and the status was displayed as green in Hawk.

Hawk now detects and displays a warning when DRBD resources are in unexpected states (disconnected, error, or standalone).

4.3 Hawk: Editing Fencing Topologies

The cluster resource manager has support for configuring multiple fencing devices, to allow backup fencing methods if the original method fails. This can for example be used to combine fencing via shared storage with UPS/PDU fencing.

Hawk now has an interface for creating and configuring fencing topologies. This functionality was previously only available via the command line interface.

4.4 Creating and Editing Pacemaker Alerts in Hawk

Pacemaker can create and edit alerts, user scripts called by the cluster when interesting events occur (nodes joining or leaving, resources starting or stopping, etc.).

On the command line, these alerts can be configured using crm configure alert.

You can now also view and configure alerts in Hawk.

4.5 Fencing Agent for Azure

Clusters running in the public cloud need special fencing mechanisms to take advantage of the APIs provided by the cloud provider.

A new fencing agent has been added which relies on the Azure Resource Management (ARM) API. The necessary Azure Resource Management packages are part of the Public Cloud Module for SLES.

4.6 Hawk: Wizard to Verify Cluster Health and Configuration

A system adminstrator needs tools to verify that the cluster configuration is valid and working properly, and make sure that the cluster nodes have the correct package versions. Previously, the command crm cluster health was available for this purpose.

A new wizard has been added to Hawk which performs the cluster health check and reports the cluster status information directly in the web interface.

4.7 Hawk: New Wizard Shows Differences in Software Package Versions Between Nodes

Mismatching package versions between live and backup systems are a problem which may only noticed at failover.

A new Hawk wizard checks the software package versions of all cluster nodes, and reports any differences it discovers.

5 Storage

5.1 DRBD Has Been Updated to Version 9.0.8

In SLE HA 12 SP3, DRBD has been updated to version 9.0.8. This version includes a number of bug fixes.

5.2 ocfs2-tools Has Been Updated to 1.8.5

The update to ocfs2-tools 1.8.5 fixes many bugs and also brings some enhancements. New functionality includes:

  • debugfs.ocfs2: The command grpextents has been added

  • fsck.ocfs2: Fix or rebuild index trees of directories

  • fsck.ocfs2: Break chain loops in group descriptors

  • fsck.ocfs2: Recalculate ECC for inode metadata block

  • fsck.ocfs2: Fix corruption when truncating reflink file

  • mkfs.ocfs2 / tunefs.ocfs2 / fsck.ocfs2: Support append direct IO incompat feature

5.3 Support for Online Size Change in cluster-md (Cluster Multi-Device)

It is now possible to resize the cluster-md RAID1 without stopping the multi-device.

Fail/remove one drive first, increase the size of drive, then add the drive back to the multi-device. After that has been done to all drives of the multi-device, grow the size of the multi-device by running:

mdadm --grow /dev/mdx --size=max

For more information, see (

6 Support Statement for SUSE Linux Enterprise High Availability Extension 12 SP3

Support requires an appropriate subscription from SUSE. For more information, see

A Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription is needed to receive support and maintenance to run geographical clustering scenarios, including manual and automated setups.

Support for the DRBD storage replication is independent of the cluster scenario and included as part of the SUSE Linux Enterprise High Availability Extension product and does not require the addition of a Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription.

General Support Statement

The following definitions apply:

  • L1: Installation and problem determination - technical support designed to provide compatibility information, installation and configuration assistance, usage support, on-going maintenance and basic troubleshooting. Level 1 Support is not intended to correct product defect errors.

  • L2: Reproduction of problem isolation - technical support designed to duplicate customer problems, isolate problem areas and potential issues, and provide resolution for problems not resolved by Level 1 Support.

  • L3: Code Debugging and problem resolution - technical support designed to resolve complex problems by engaging engineering in patch provision, resolution of product defects which have been identified by Level 2 Support.

SUSE will only support the usage of original (unchanged or not recompiled) packages.

7 How to Obtain Source Code

This SUSE product includes materials licensed to SUSE under the GNU General Public License (GPL). The GPL requires SUSE to provide the source code that corresponds to the GPL-licensed material. The source code is available for download at Also, for up to three years after distribution of the SUSE product, upon request, SUSE will mail a copy of the source code. Requests should be sent by e-mail to or as otherwise instructed at SUSE may charge a reasonable fee to recover distribution costs.

8 More Information and Feedback

  • Read the READMEs on the CDs.

  • Get detailed changelog information about a particular package from the RPM (where FILENAME is the name of the RPM):

    rpm --changelog -qp FILENAME.rpm
  • Check the ChangeLog file in the top level of CD1 for a chronological log of all changes made to the updated packages.

  • Find more information in the docu directory of first medium of the SUSE Linux Enterprise High Availability Extension media. This directory includes a PDF version of the High Availability Guide.

  • contains additional or updated documentation for SUSE Linux Enterprise High Availability Extension 12 SP3.

  • Visit for the latest product news from SUSE and for additional information on the source code of SUSE Linux Enterprise products.

Copyright © 2010- 2017 SUSE LLC.

Thanks for using SUSE Linux Enterprise High Availability Extension in your business.

The SUSE Linux Enterprise High Availability Extension Team.

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