HP-UX Workload Manager User's Guide

Introduction
What is HP-UX Workload Manager?
Chapter 1 45
You can assign secure compartments to workload groups, creating the
secure compartments with the HP-UX feature Security Containment.
Secure compartments isolate files and processes. WLM can then
automatically allocate resources for these secure compartments.
When you configure WLM, you define one or more SLOs for each
workload group and prioritize them. To satisfy the SLOs for the workload
groups, WLM will then automatically manage CPU resources and,
optionally, real memory and disk bandwidth (WLM management of
workload groups is confined within the HP-UX instance or partition; no
allocation is made across partitions.) If multiple users or applications
within a workload group are competing for resources, standard HP-UX
resource management determines the resource allocation within the
workload.
With real memory, WLM allows you to specify lower and upper limits on
the amount of memory a workload group receives. Disk bandwidth
shares can be statically assigned in the configuration file.
NOTE The WLM daemon is designed to use minimal system resources. All of
the daemon’s processes run in the PRM_SYS (ID 0) workload, as explained
in the section “Reserved workload groups” on page 163.
Summary
WLM can manage the following resources for your workloads:
• CPU (cores)
Arbitrates CPU resource requests to ensure that high-priority SLOs
meet their objectives. SLOs make CPU resource requests for
workloads (or workload groups). CPU resources can be allocated in:
— Time slices on several cores
— Whole cores used by PSET-based workloads
— Whole cores used by vPar-based workloads
— Whole cores used by nPartition-based workloads (with each
nPartition using Instant Capacity software)
A workload might not achieve its CPU request if CPU resources are
oversubscribed and the workload’s SLOs are low priority.