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

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#/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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Contents HP Global Workload Manager 7.4 User Guide Acknowledgements Contents Support and other resources Additional configuration and administration tasksIndex GWLM Overview Benefits of using gWLMComparison of PRM, WLM, and gWLM features OverviewScheduler fss group. gWLM manages a workload by Concepts and terms for using gWLMWould make for a workload-without actually affecting SRD GWLM management modelHow gWLM allocates CPU resources Assumptions Available interfacesFinding more gWLM information Where to find additional informationLearn about other gWLM commands Policy types Configuring gWLM to manage workloadsPolicy types Choosing a policy type Choosing a policy typeCombining the different policy types Using the wizardSeeing how gWLM will perform without affecting the system Getting started with gWLM# /opt/gwlm/bin/gwlmagent Seeing gWLM in action# perl -e ’print $$\nwhile 1 ’ & 1 Fixing the amount of CPU resources a workload gets Common uses for gWLMSetting up gWLM initial setup steps Common configuration tasksCreating a new policy Changing from advisory mode to managed modeChanging which policy is associated with a workload Editing a policyStop managing a workload Adding a new compartment or GiCAP group member to an SRDStop managing an SRD Quick Link Option High-Level view Viewing gWLM reports in monitor-Only modeMonitoring workloads and gWLM Monitoring workloadsMessage logs Monitoring gWLM from the command lineHP-UX /var/opt/gwlm/gwlmcommand.log.0 Monitoring gWLM with GlancePlus Viewing HP Systems Insight Manager eventsSecuring database communications SecurityGeneral security topics Securing gWLM communicationsSecurity Manually adjusting CPU resources Additional configuration and administration tasksSetting aside space for historical data Manually adjusting memory resourcesTips for backup and restore Setting cache size for historical configuration dataSetting database recovery model Creating a database maintenance planCMS properties Setting gWLM propertiesSetting gWLM properties Agent properties # Severe # Warning # Info # Config # Fine # Finer # Finest Communications ports Controlling gWLM’s startup behavior# /opt/gwlm/bin/gwlmagent --enablestartonboot Related events How the automatic restart worksNode Failed to Rejoin SRD on Start-up event Manually clearing an SRD# gwlm undeploy --srd=SRD--force Nested partitions Nesting partitionsChanging the interval in HP System Insight Manager Using gWLM with Hyper-ThreadingChanging the interval on the command line Changing the gWLM resource allocation intervalShows a possible scenario Using gWLM with hosts on multiple LANsMultiple network interface cards Creating Golden ImagesGet the IP address configured for the host using nslookup Incorrectly configured host name or IP addressEnabling or disabling dumping core for gWLM Unable to create new native threadCore dump file is available in root directory Information to collect before contacting HP How to contact HPSubscription service Support and other resourcesTypographic conventions HP authorized resellersRelated information User input Documentation feedback Compatibility with agents Limitations Global Workload Manager known issuesCompatibility with PRM and WLM Unable to build a single shared resource domainHost name aliases are not supported Making a configuration change to a large SRD is slowRare incompatibility with virtual partitions Integrity VM prevents discovery of psets and fss groups Deleting workloads takes a long timeCustom metrics lost on redeploy Information error during shutdownProcess placement using psrset is ignored Major issues Remove old configuration data from the gWLM database Documentation or minor issuesCMS is slow to respond Cell-local processors and iCAP environmentModifying Java while gWLM is running Error during discovery of compartmentsCombining psets and virtual partitions Only one SRD is allowed to be deployed Missing or unexpected historical data system clocks differSample missing at start or end of gwlmreport output Scripts not placed in correct workloads Processes moved to default pset or default fss groupSRD deployment times out and displays a blank screen Application hangs in fss groupUnable to remove workload from nested partitions SRD Configuration of agent and CMS not synchronizedChanges in sizes in Discovery Negative current size for Nonvm Missing historical data gWLM CMS daemon/service restartedUnmanaging a VM or vPar that is on leaves SRD undeployed SRD IndexIndex

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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