With the release of AIX 6.1, IBM introduced a new virtualization capability called Workload Partition (WPAR). A WPAR is a software-created, virtualized operating system environment within a single AIX image. Each workload partition is a secure and isolated environment for the application that it hosts. The application in a WPAR “thinks” that it is being executed in its own dedicated AIX instance.

WPARs can be created in all hardware environments that support AIX 6.1 and later. This includes, for example, POWER4 machines, which are supported by AIX 6.1. Figure 7-1 shows that you can create workload partitions within multiple AIX instances on the same physical server, whether they execute in dedicated LPARs or micropartitions.

WPARs have the following characteristics:

There are multiple types of WPARs:

Both types can run within a single AIX OS image, which is referred to as the global environment. Starting with AIX 7.1 and POWER7, versioned WPARS are available. Versioned WPARs provide a different OS version in the WPAR than the OS version of the global environment, for example an AIX 5.2 WPAR running in an AIX 7.1.

A System WPAR presents a secure and isolated environment that is most similar to a standalone AIX system. Each System WPAR has dedicated writable file systems, although it can share the global environment /usr and /opt file systems in read only mode. Here, we term this difference as Unshared and Shared, respectively.

System WPARs are autonomous virtual system environments and appear, to applications that are running within the WPAR, as though they run in their own separate instance of AIX. Multiple System WPARs can run within the single global AIX image, and each WPAR is isolated from other WPARs.

System WPARs have the following attributes:

The combination of isolation and resource sharing makes System WPARs an excellent feature for consolidating several SAP systems, independent from the underlying POWER hardware. Using a single global AIX image simplifies OS maintenance for multiple SAP systems; however, using one global OS image also introduces a very obvious single-point-of-failure and introduces new dependencies.

Hence, consolidating non-production and smaller SAP instances is expected to be the major use case for this feature.

An Application WPAR has all of the process isolation that the System WPAR does. However, it shares the file system name space with the global system and any other Application WPAR that is defined within the system.

An Application WPAR is essentially a wrapper around a running application or process for the purposes of isolation and mobility. It lacks some of the system services that the System WPAR provides, for example, it is not possible to log in or to telnet into an Application WPAR. When the application that is running in an Application WPAR terminates, the WPAR also ceases to exist.

An SAP system implementation is a complex environment with multiple components, specific requirements to the AIX environment, and many processes. Therefore, Application WPARs are not supported for SAP applications.

For more information about WPARs, refer to Introduction to Workload Partition Management in IBM AIX Version 6.1, SG24-7431, available at:

Versioned WPARs are intended to provide runtime environments for applications, where the manufacturer of the software does not exist anymore or is not able to provide versions of his software for newer AIX releases. In these cases a client might not be able to update their hardware to a new generation, since the new hardware might not support the OS version required by the old software. Since SAP is providing its software stack very quickly on new versions of AIX and also recertifies older software versions to new AIX versions, SAP does not support versioned WPARs.

You can use all SAP applications, which are based on SAP NetWeaver Application Server for ABAP and JAVA and are available on AIX 6.1 and later, in WPARs. For details, review the SAP Product Availability Matrix at:

Detailed information about the current support status can be found in SAP Note 1105456. This note also documents all prerequisites and restrictions and is updated regularly. At the time this book was written the following restrictions and prerequisites applied:

In this section, we provide the scenarios to which the setup is restricted.

You can install and run SAP applications in an Unshared System WPAR without any changes required in the SAP installer. Just follow the instructions in the SAP Installation Guide.

SAP applications installed in an Unshared System WPAR can be upgraded with standard SAP upgrade procedures without any restrictions. Just follow the instructions in the SAP Upgrade Guide.

Manual migration scenarios:

The manual migration of an SAP installation from an LPAR into an Unshared System WPAR is supported using the standard SAP Homogeneous System Copy procedure (see the standard SAP System Copy documentation).

You can install and run SAP applications in a Shared System WPAR without any changes required in the SAP installer, after some WPAR-specific preparations. Review 7.4, “Sample installation of SAP NetWeaver 7.0 in a Shared System WPAR” on page 73. Follow the instructions in the SAP Installation Guide.

You must first create a Shared System WPAR. You can specify, for example, the Volume Group to be used for the WPAR-specific file systems, the host name (DNS entry exists), and to duplicate the network name resolution from the global environment:

After a few (in our test scenario 2-3) minutes, the WPAR is created, and you can start it with the following command:

Prepare the system (global environment and WPAR) for the SAP installation:

After this preparation, you can run the SAP installation as described in the SAP installation guide without any restrictions.

Live Application Mobility requires an additional Licensed Program Product called Workload Partitions Manager™ for AIX.

The Workload Partitions Manager provides more advanced features for managing multiple WPARs, including:

To transfer an application to another LPAR or server, a checkpoint/restart feature is used. During a WPAR checkpoint, the current state of running applications is saved and during restart operations resumed in the new AIX image.

With this feature, it is possible to move WPARs between compatible systems without significantly affecting WPAR users.

Live Application Mobility is not supported in SAP environments. Review SAP Note 1105456 for current support.