High Availability Option (HAO) for Red Hat Enterprise Linux on IBM System z

What is HAO for RHEL on System z?

Our average customer spends $22,000 on this.

***Now supports SCSI Hard Drives***

Developed and supported by Sine Nomine Associates and incorporating Red Hat technologies, the High-Availability Option (HAO) for Red Hat Enterprise Linux on Systems z provides software and support tooling to implement clustered, highly available system services and data storage services on System z hardware.

HAO provides workload distribution, cluster creation and management software and enterprise-level support for GFS2, a comprehensive cluster-aware file system that is aware of the System z hardware capabilities for zero down time service. The product enables cluster communications via TCPIP and IUCV message transports, and provides the ability to cluster combinations of z/VM guests and LPARs running RHEL on the same physical system or different physical systems (subject to the documented hardware and disk sharing configuration limitations supported by IBM).


Target Audience for HAO for RHEL on System z


HAO is intended as a general purpose clustering infrastructure component for all users of RHEL on System z who need to provide highly available system services and data storage systems on System z hardware.


HAO for RHEL on System z Features


HAO provides a comprehensive clustering and workload distribution solution for RHEL deployments on System z equivalent to the solutions provided on Intel hardware by Red Hat. The package includes:

  • Cluster failover infrastructure tooling
  • Cluster failover policy definition, management, deployment, and monitoring tools
  • GFS2 (a cluster-aware general purpose file system) and support
  • Support for LPAR and z/VM implementation
  • Load balancing and workload distribution software
  • Load balancing and workload distribution policy definition, mangement, deployment and monitoring tools

The package is designed to be functionally equivalent to the Red Hat Cluster Suite, and to leverage existing skills within your organization on cluster definition, application migration and management, and cluster operations.


HAO has been tested with popular commercial enterprise applications such as DB/2 and Websphere MQSeries high-availability requirements. SNA engineers can assist with implementing HA support for many products as part of separate services engagements.


HAO for RHEL on System z is a "Red Hat Ready" registered ISV Partner product.




HAO for RHEL on System z is currently supported for the following RHEL releases:

  • RHEL 6.2 or higher on System z
  • ClefOS 6.2 or higher on System z
  • RHEL 7 and higher on System z
  • ClefOS 7 and higher on System z

All RHEL 6 releases supported by Redhat and all z/VM releases supported by IBM are supported for HAO operation.

We recommend using the most up to date z/VM available, enabling the SSI Option, and using RHEL 6.9 or higher. The SSI Option for z/VM is not required for HAO operation, but SSI function is exploited if present.

Software support and maintenance is included in the annual subscription price.


Delivery and Installation

HAO for RHEL on System z is delivered in electronic form to Internet-connected sites, and is installed using standard RHEL software installation processes. HAO is available for installation immediately upon payment of the invoice.



HAO for RHEL on System z is licensed on an annual basis by a subscription fee, which is priced based on the effective capacity used to support RHEL systems running HAO across your entire enterprise. A worksheet provides a simple way to estimate your costs. Please contact us for details and pricing.


Where Can You Find Out More About HAO for System z?

Additional information, manuals, white papers and brochures about HAO for System z and System p are available from the following sources:

If you have other questions, or want to arrange a trial license, please contact us here.