System Administration
Showing results for 
Search instead for 
Did you mean: 

Re: WLM amd PRM on nPar/vPar system

Go to solution
Super Advisor

WLM amd PRM on nPar/vPar system

What is the difference between WLM and PRM on nPar and vPar systems ?

Steven E. Protter
Exalted Contributor

Re: WLM amd PRM on nPar/vPar system

WLM and PRM work exactly the same in a vpar as they would on a system that is running without npar/vpar.

This is my understanding based on reading Charles Keenan's HP-UX CSA and skimming Pantiowski's Virtual Partitions.

Steven E Protter
Owner of ISN Corporation
Raj D.
Honored Contributor

Re: WLM amd PRM on nPar/vPar system

Hi Shiv ,

Well in a short ..

WLM: Workload Manager.
PRM: Process Resource Manager.

nPar: Node Partition./ Hard Partition.
vPar: Virtual Partition.


WLM is a resource management tool that provides automatic CPU resource allocation and application performance management based on prioritized service-level objectives (SLOs). In addition, real memory and disk bandwidth allocations can be set to fixed levels in the configuration.

You can define workloads based on:
nPartitions that use Instant Capacity
HP-UX virtual partitions
Resource partitions, which can be:
Whole-CPU: HP-UX processor sets (PSETs)
Sub-CPU: Fair Share Scheduler (FSS) groups

PRM is a tool that controls the amount of resources processes use. The control over the amount of resources used is normally done when the system is at peak load with 100% utilization of CPU, memory, or disk.

Hard Partitions (nPartitions) have dedicated hardware within an HP 9000 that work independently from other nPartitions within the same server. This independence includes both hardware and software isolation from other nPartitions. Virtual Partitions (vPars) have full software isolation from one another. nPartitions have both software and hardware isolation from one another. An nPartition could be divided into multiple vPars.

The basic building block of an nPartition is the cell. Each cell has on it processors and memory that are assigned exclusively to that nPartition. I/O chassis are also exclusively assigned to nPartitions. Multiple cells can be combined to produce large nPartitions.

Virtual Partitions (vPars) you can take almost any HP 9000 server and turn it into many "virtual" computers. These virtual computers can each be running their own instance of HP-UX and associated applications. The virtual computers are isolated from one another at the software level. Software running on one Virtual Partition will not affect software running in any other Virtual Partition. In the Virtual Partitions you can run different revisions of HP-UX, different patch levels of HP-UX, different applications, or any software you want and not affect other partitions.

There are some base requirements that must be met in order to run vPars on your system. At the time of this writing, the following minimum requirements must be met for each vPar on your system:

Minimum of one CPU.

Sufficient memory to run HP-UX and any other software that will be present in the vPar.

A boot disk off which HP-UX can be booted. At the time of this writing it is not possible to share bus adapters between vPars. Therefore, a separate bus adapter is required for each of the vPars. This requirement may have been removed by the time you read this book.

A console for managing the system. The console can be either physical or virtual. We'll cover the console in detail in the book.

An HP 9000 system supported by HP-UX 11i. At the time of this writing only HP-UX 11i is supported in vPars. With systems based on the Itanium processor, there are plans to support numerous operating systems in vPars in the future.

The system we'll use in most of the examples throughout this chapter is an rp 5400 (formerly know as L-Class) system that meets all of the requirements in the previous list. You may also want to have additional disks and a separate LAN card in your vPars. I strongly recommend the LAN card so that you can establish TELNET, or other, sessions to your vPars rather than connecting to them only from the console. The LAN card is also required to perform backup and Ignite-UX-related work.

If you have Instant Capacity on Demand (iCOD) employed on your server, all CPUs must be activitated in order for vPars to work. When employing Processor Sets (psets) in a vPar, use only bound CPUs.

Enjoy ..
" If u think u can , If u think u cannot , - You are always Right . "
Raj D.
Honored Contributor

Re: WLM amd PRM on nPar/vPar system

Also ..few links , may help...




VPAR: (good book)

Specially VPAR book: HP-UX Virtual Partitions
By Marty Poniatowski

Publisher : Prentice Hall PTR
Pub Date : March 04, 2002
ISBN : 0-13-035212-8
Pages : 1040
Supplier : Team FLY

" If u think u can , If u think u cannot , - You are always Right . "
Trusted Contributor

Re: WLM amd PRM on nPar/vPar system

â hardware isolation per cell
â complete software isolation
â cell granularity
â multiple OS images

â complete software isolation
â CPU granularity
â dynamic CPU migration
â multiple OS images

â dynamic resource allocation
â FSS - share (%)granularity
â PSETs â processor granularity
â 1 OS image

HP-UX WLM (workload manager)
- automatic goal-based resource allocation via set SLO(service-level objective)s

Kamal Mirdad
Mahesh Kumar Malik
Honored Contributor

Re: WLM amd PRM on nPar/vPar system

Hi Shiv

Following links may be of help

WLM (Work Load Manager)

PRM (Process Resource Manager)