Resizing partitions automatically with HP-UX Workload Manager

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WLM is most effective in managing applications that are CPU-bound. It adjusts the CPU allocation of
a group of processes known as a workload, basing the adjustment on the current needs and
performance of applications in that workload. A workload can be based on the collection of
processes in:
• nPartitions that uses Instant Capacity
• Virtual partitions (vPars)
• HP Integrity Virtual Machines (Integrity VM) hosts
• Resource partitions, which can be:
– Whole-core: HP-UX processor sets (pSets)
– Sub-core: Fair Share Scheduler (FSS) groups (WLM creates FSS groups using HP Process
Resource Manager (PRM))
Note
As of WLM A.03.01, PRM is no longer included with the WLM bundle. If
PRM C.03.00 or later is already on the machine on which you must install
or upgrade WLM, you can continue to manage FSS and pSet-based
workload groups (just as if PRM had been installed with WLM). If you are
installing WLM for the first time on a machine, you can use a strictly host-
based configuration (no FSS or pSet workload groups). However, to
manage FSS and pSet-based workload groups, you must install PRM
(C.03.00 or later) separately.
To have WLM migrate resources among workloads as needed, you create one or more SLOs for each
workload. In defining an SLO, you specify its relative level of importance (priority), and typically, you
also specify a usage goal to attain a targeted resource usage. If a performance measure (metric) is
available, you can specify a metric goal. As the applications run, WLM compares the application
usage or metrics against the goals. To achieve the goals, WLM then automatically adjusts CPU
allocations for the workloads.
To manage your systems more effectively, you can use WLM with several HP products, such as:
• Virtual partitions—For systems with partitions, WLM provides a global arbiter that takes input from
the WLM instances on the individual partitions. The global arbiter then moves cores among
partitions, if needed, to better achieve the SLOs specified in the WLM configuration files that are
active in the partitions.
• nPartitions—The WLM global arbiter also takes input from the WLM instances on individual
nPartitions. For nPartitions with Instant Capacity software installed, WLM can simulate the
movement of cores among the partitions, deactivating unneeded cores in one or more partitions
and then activating cores on the partitions where CPU resources are most needed. WLM can be
integrated with HP Serviceguard to reallocate resources in a failover situation according to defined
priorities. For more information on integrating with HP Serviceguard, see the white papers, “HP-UX
Workload Manager overview” and “More efficient high availability and resource utilization
through manageability (integrating HP-UX Clustering, Instant Capacity, HP-UX Workload Manager)”
available from the information library at:
http://www.hp.com/go/wlm
• Virtual machines—HP Integrity Virtual Machines is a robust soft partitioning and virtualization
technology that provides operating systems isolation, shared CPU resources (with sub-core
granularity), shared I/O, and automatic dynamic resource allocation. It is available for HP-UX 11i
v2 and later, running on HP Integrity servers. Each virtual machine is similar to a virtual partition but
emulates a generic server. Each virtual machine runs its own operating system. HP Integrity Virtual
Machines can be used within hard partitions. You can run WLM both on the Integrity VM host and
in an Integrity VM (guest), with each WLM running as an independent instance: