#/opt/wlm/bin/wlmd -k

Rare incompatibility with virtual partitions

Depending on workload characteristics, gWLM can migrate CPU resources rapidly. This frequent migration can potentially, although very rarely, produce a race condition, causing the virtual partition to crash. It can also produce a panic, resulting in one or more of the following messages:

No Chosen CPU on the cell-cannot proceed with NB PDC.

or

PDC_PAT_EVENT_SET_MODE(2) call returned error

Workaround

Upgrading to vPars A.03.04 resolves this issue.

With earlier versions of vPars, you can work around this issue as follows: Assign (using path assignment) at least one CPU per cell as a bound CPU to at least one virtual partition. (It can be any virtual partition). This ensures that there is no redesignation on CPU migrations. For example, if you have four cells (0, 1, 2, 3), each with four CPUs (10, 11, 12, 13) and four virtual partitions (vpar1, vpar2, vpar3, vpar4), you could assign 0/1x to vpar1, 1/1x to vpar2, 2/1x to vpar3, and 3/1x to vpar4, where x is 0,1,2,3.

Workloads in gWLM do not follow associated Serviceguard packages

With the exception of virtual machines, a workload can be managed by gWLM in only one deployed SRD at a time. As a result, if a workload is directly associated with a Serviceguard package (using the selector in the Workload Definition dialog), gWLM can manage it on only one of the hosts on which it might potentially run. However, management of such a workload might disrupt the HP Matrix OE visualization and Capacity Advisor tracking of the workload utilization between cluster members. Thus, it is recommended that you not directly manage a workload associated with a Serviceguard package.

Workaround

For all hosts to which a workload associated with a Serviceguard package might fail over, you must apply a policy to an enclosing operating system instance (virtual partition or nPartition). You can use a gWLM conditional policy to change the resource allocation depending on which packages are present. This enables you to control the resource allocation of the enclosing operating system instance and still monitor the workload via HP Matrix OE visualization.

Host name aliases are not supported

Host name aliases are not supported by gWLM. Only canonical DNS host names (fully qualified domain names) are supported.

Workaround

Use only canonical DNS names when configuring gWLM through either System Insight Manager or an XML file used with the gwlm command.

Making a configuration change to a large SRD is slow

Changes made to the configuration of a large SRD that is deployed might take a long time (several minutes) to take effect.

Workaround

There is no workaround. The amount of time needed to complete a change depends on the time it takes to communicate with all the compartments in the SRD.

Events for gWLM CPU migration can affect System Insight Manager CMS performance

The HP products System Fault Management (SFM) and Event Monitoring Service (EMS hardware monitors in particular) generate events, or indications, when CPUs are migrated. Depending on workload characteristics, gWLM can migrate CPUs rapidly. Over time, this frequent migration can

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HP UX 11i Workload Management (gWLM/WLM) Software manual Rare incompatibility with virtual partitions
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UX 11i Workload Management (gWLM/WLM) Software specifications

HP-UX 11i Workload Management (gWLM/WLM) software is an integral component of HP's premier UNIX operating system, designed to enhance system performance and resource management across diverse workloads. This advanced tool allows system administrators to monitor, control, and allocate resources effectively to achieve optimal performance, reliability, and service levels in enterprise environments.

One of the main features of gWLM/WLM is its ability to classify workloads and manage them according to specific policies set by the administrator. By using service level objectives (SLOs), administrators can define the performance criteria for various applications and workloads. gWLM continuously tracks these workloads, ensuring that they adhere to the defined SLOs, thus maintaining a high level of application performance.

The software employs resource pools, which segment resources such as CPU, memory, and I/O bandwidth among different workloads based on predefined priorities. This capability ensures that critical applications receive the resources they require, even during peak usage periods, thereby preventing resource starvation that could lead to system slowdowns or crashes.

Another significant characteristic of gWLM/WLM is its real-time monitoring and reporting capabilities. The software provides detailed insights into resource utilization, workload performance, and system health. Administrators can access this information through a user-friendly interface, allowing for informed decision-making and proactive management.

Integration with HP Serviceguard adds another layer of functionality, enabling high availability for critical applications. gWLM can orchestrate workload migration to ensure that service levels are maintained, even in the event of hardware failures or resource contention.

The technology behind gWLM/WLM is built on advanced algorithms that leverage historical data and predictive modeling to optimize resource allocation dynamically. This means that as workloads change, the system can automatically adjust resource distribution to meet performance targets without the need for constant manual intervention.

gWLM also supports integration with various enterprise management tools, enabling administrators to implement comprehensive monitoring and management strategies across the IT infrastructure. The scalability of gWLM allows organizations of all sizes to benefit from its robust workload management features, ensuring that they can adapt to changing demands in their operational environments.

In summary, HP-UX 11i Workload Management software offers a sophisticated solution for optimizing resource utilization, managing workloads effectively, and maintaining high performance in complex enterprise environments. Its comprehensive features and technologies make it an essential tool for any organization seeking to enhance their IT operations.
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