IBM Virtual IO Server

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Virtual I/O (VIO) and Virtualization

Briefly What is Virtualization?


The Virtual I/O Server is part of the IBM System p5 Advanced Power Virtualization hardware feature. Virtual I/O Server allows sharing of physical resources between LPARs including virtual SCSI and virtual networking. This allows more efficient utilization of physical resources through sharing between LPARs and facilitates server consolidation.

This allows a single machine to run multiple operating system (OS) images at the same time but each is isolated from the others. POWER4 based machines started this in 2001 by allowing many Logical Partitions (LPAR) to run on the same machine using but each using different CPUs, different memory sections and different PCI adapter slots. Next came with POWER4, the ability to dynamically change the CPU, memory and PCI adapters slots with the OS running. With the introduction of POWER5 in 2005, further Virtualization items have been added:

  1. Less than a whole CPU can be allocated to a LPAR
  2. The LPARs sharing CPUs can be setup to allow automatic load balancing (in milliseconds)
  3. The sharing of disks, networks, optical devices (CD/DVD) using a VIO Server (see below)

If you want more, try these two links:

Briefly, What is Virtual IO (VIO)?

This is a logical partition (LPAR) on a pSeries machine controlled by the HMC or IVM that owns hardware adapters like SCSI disks, Fibre-Channel disks, Ethernet or CD/DVD optical devices but allows other LPARs to access them or a part of them. This allows the device to be shared. The LPAR with the resources is called the VIO Server and the other LPARs using it are called VIO Clients. For example, instead of each LPAR having a SCSI adapter and SCSI disk to boot from they can shared one disk on the VIO Server. This reduces costs but eliminating adapters, adapter slots and disks. This Client:Server access is implemented over memory within the machine for speed.

For a more detailed explanation, please click here: VIOS Detail

Virtualization Best Practice

To aid the sharing of good practice, hints and tip the Best Practice guide is a constant work in progress and a community based self help document. If you need some guideance take a look or if you have a really good idea that can help others please add it here.

Virtualization Back to Power Basics Movies

You can watch and download ten small movies of hands-on use of PowerVM and Virtualization on the AIX6 and POWER6 Movie AIX Wiki page at:

Look for the Back to Power Basics Series. Each is around 10 minutes long and is a good introduction to PowerVM and the Virtual I/O Server and many of the features it provides.

Virtualization Assessments

Use these questionaires to evaluate your company and your personal readiness for Virtualizition and APV technology to reap the beneifts of:

  • Reduced costs,
  • Higher peak performance,
  • Rapid response to business needs and
  • Flexibility.

    The five stages (see below) of Virtualization have a set of questions each. Then via a simple scoring system that will award a Bronze, Silver or Gold level. The questions that you answered "no" will suggest an action list that you use to plan improvements and develop skills..

What to do if you want to develop your p5 Virtualisation skills?

The below diagram shows the suggested roadmap for developing Virtualisation Skills:

Each level involes back ground reading, Redbooks and the education available as highlighted below (see the table further below for the meaning of the reference numbers):


Level Skills What to read? Documentation Redbooks Education
1 Pre-requsites       AIX 5.3 System Administration

If only using Linux and IVM then just Linux System Admin

If using Linux and HMC then AIX System Admin is recommended

See IBM Learning Services at Curriculum
2 Virtualisation Concepts &

pSeries p5 Implementation
0, 4, 9, 10, 11      
3 Product information 1, 2, 3, 9     235
4a Basic Hands-on for IVM based Virtualisation 13, 18, 19, 20 16,17 103  
4b Basic Hands-on for HMC based Virtualisation 18, 6 (IBMers only), 21 16, 17 101 231 (POWER5), 232 (POWER4)
5 Advanced Hands-on for HMC based Virtualisation

includes dual VIO Server, SAN and VLAN
5, 7, 8, 12, 15, 21   102 233 (Performance), 234(underdevelopment)

Key Places For More Information and Building Virtualization Skills

We can recommend the following places:


Reference Number Type Name URL Size Comments
1 Website VIO Server home Link 1 page the Home for VIO Server
2 Website White papers, FAQ & Data sheet Link 3 pages from here
3 Website Download of the updates Link 1 page the most important website
4 Whitepaper Overview of Virtualization & setting up the VIO Server Link 21 pages Excellent start pack example with all the details and background
5 Whitepaper Virtualization working with VLANS Link 18 pages Details VLAN paper from the developer
6 Powerpoint Power5 Virtual I/O (VIO) Options

(internal to IBM only)
Link 94 pages diagrams of the correct setups and procs+cons for each.
7 Whitepaper POWER5 Virtual SCSI Performance Study

(internal to IBM only)
Link 21 pages A case study with vSCSI and DS4500 SAN disks
8 Whitepaper POWER5 Processors Virtual SCSI Throughput Analysis Link 23 pages A case study of vSCSI and how small the overhead is.
9 Website Advanced POWER Virtualization on eServer p5 Link 1 pages Lots of links to other articles and websiates
10 Whitepaper IBM p5 570 Server Consolidation Using POWER5 Virtualization Link 8 pages Good whitepaper on appraoching consolidation with APV
11 Whitepaper IBM p5 570 Workload Balancing Using POWER5 Virtualization Link 18 pages Good worked example of what to expect
12 Web page Virtual I/O Server sizing Link 1 page Be sure to follow links to other documentation
13 Whitepaper Use the Integrated Virtualization Manager with Linux on POWER Link 22 pages Blow by blow HowTo
14 Whitepaper How to work with VLANs using the IBM Virtual I/O Server Link 9 pages What you really need to know to get started with VLAN and APV
15 Certification Certified p5 Virtualization Technical Support AIX 5L V5.3 Link 1 Book you exam here.
16 Documentation Using the Virtual I/O Server Link 154 pages Impossibly to find as its URL changes so often !!!! (Last link URL contained "v1r2s" instead of current "v1r3s".)
17 Documentation VIO Server and PLM Commands Reference Link 174 pages trouble is the URL keeps changing - good luck finding it !!
18 Wiki Virtualization Best Practice Virtualization Best Practice 6 pages User wiki additions to the Best Practice Redbook
19 Wiki Integrated Virtualization Manager Wiki IVM whitpaper 16 pages Overview and excellent summary of the features
20 Wiki Advanced IVM Topics Link 21 pages Good further reading after the IVM Redbook
21 Website The definative list of what is supported Link 4 pages Check here for features supported
101 Redbook Advanced POWER Virtualization on IBM p5 Servers

  • Introduction and Basic Configuration, SG24-7940, public

  • includes configurations and setup examples
Link 446 pages Excellent reference work and must read if you serious on APV
102 Redbook Advanced Power Virtualization on IBM p5 Servers

  • Architecture and Performance Considerations, SG24-5768,

  • follow on Redbook with advanced topics and details
Link 436 pages Excellent reference work
103 Redbook Integrated Virtualization Manager with VIO Server

  • the IVM starter pack and Handbook
Link 90 pages Excellent start for IVM
104 Redbook Advanced Power Virtualization Best Practice Link 150 pages Excellent up to date extra ideas
230 Education AIX pSeries System Administration Curriculum Curriculum
231 Education System p LPAR and Virtualization I: Planning and Configuration Go to

and search for AU73
5 days  
232 Education System p Virtualization and LPAR for pSeries Power4 Administrators Go to

and search for AU74
3 days  
233 Education System p LPAR & Virtualization III: Virtualization Performance Mgnt

including VIO Server
Go to

and search for AU75
5 days  
234 Education System p LPAR and Virtualization II: Implementing Adv Configurations Go to

and search for AU78
4 days  
235 Education eServer, pSeries and AIX Product Overview Go to

and search for AM21
2 days  

For more technical details a good place to start learning is the IBM Redbooks which are freely available for download in .PDF format:

Alternative solutions:

The Linux SUSE SLES 9 operating system can also be used as a VIO Server (but with different features and not supported in the same way as the IBM VIO Server)

The postings on this site solely reflect the personal views of the authors and do not necessarily represent the views, positions, strategies or opinions of IBM or IBM management.