What is Virtualization?

Virtualization is the process of consolidating physical machines and/or servers onto one physical machine, thus creating “Virtual Machines” that share the central Server’s resources (Processor, Memory, Storage, etc.) virtualization allows the creation of multiple systems, the physical systems that are already in use can have its data and information moved to the mainframe and used as if it was still a “physical” box.  This also will allow that system to be used from virtually anywhere access is allowed.  By being moved to the mainframe system, these existing systems will also become more isolated and secure than it was as an individual system.

Virtualization consolidation

As a Virtual Machine, or VM, the system has more controlled and secure access to its data. With adjusted settings, the VM will be completely isolated from other systems and completely unaffected by other systems on the mainframe, whereas in its physical state, the machine could be intruded or accidentally affected, or crashed, by other systems within that network.  Virtual Machines are impenetrable within a mainframe environment. Virtualization ultimately allows multiple, different operating systems to run on the mainframe at the same time.


Advantages of virtualization


The virtual machine environment is highly flexible and adaptable.  New Linux guests can be added to a VM system quickly and easily without requiring dedicated resources.  This is useful for replicating servers in addition to giving users a highly flexible test environment

Sharing resources

Resources can be shared among multiple Linux images running on the same VM system. These resources include: CPU cycles, memory, storage devices, and network adapters.

Server hardware consolidation

Running tens or hundreds of Linux instances on a single System z server offers customers savings in space and personnel required to manage real hardware.

System z advantages

Running Linux on VM means the Linux guest(s) can transparently take advantage of VM support for System z hardware architecture and features

z/VM Connectivity

z/VM provides high-performance communication among virtual machines running Linux and other operating systems on the same processor.  Simplification of the network by using HiperSockets may provide savings and reduce cabling, hubs, switches, and routers, as well as help to reduce maintenance effort.

Horizontal growth

An effective way to grow your Linux workload capacity is to add more Linux guests to a VM system.  z/VM V5 supports Integrated Facility for Linux (IFL) processors, the attractively-priced hardware feature for Linux workloads available for System z.   An IFL is an dedicated processor for running Linux on the mainframe, designed to reduce software costs specifically.   

IBM introduced a new engine-based Value Unit pricing announced for z/VM V5, replacing the per-engine pricing model that was available with z/VM V4.  Engine-based Value Unit pricing is designed to provide a decreasing price curve as hardware capacities and workload grow, which may help improve price/performance.

So, why use Linux on the mainframe?

Linux is more secure and also stable than most OS’s.  Since its creation, Linux has been able to remain clear of mass-spread viruses or spyware.  This will disable the need for the organization to purchase any antivirus software and the subscriptions such as it would on Windows.   Also, by Linux being open source, the vast majority of Linux based software is also completely free and available for download at any time.

Mainframe customers just about always buy support.   Annual subscriptions for Red Hat is 15 to 18 thousand per IFL.   Suse is similar.  Linux on z is typically used to run licensed enterprise software rather than free open source, so there are costs as with most servers.  However  there is still cost savings for many workloads due to consolidation.

Some real examples of the benefits of virtualization, specifically Linux, includes Nationwide Insurance.  Nationwide.com runs on WebSphere¸ one of IBM’s lead web application server products, on Linux for System z.  They expect to save $16M over the next 3 years from their initial deployment of the Linux application.  The initial deployment consolidated over 250 Production, Development & Test Servers down to only 6 IFLs, or Integrated Facility for Linux.  

Bank of New Zealand also engaged in a consolidation of its own.  The bank reduced over 200 Sun servers down to one System z10 running Red Hat Enterprise Linux.  They also reduced their datacenter footprint by 30%, reduced the heat output by 33%, and power consumption by very close to 40%.  Also, they saved in human resources by having only one assigned administrator per 200 virtual servers.

As both of these examples show, benefits from virtualization are indeed REAL!



(*** Please follow me at mainframemindedaggie ****)

New z/VM Guest

Editor’s Note: This is part two of a multi-post series on CSL-WAVE, a systems management GUI for z/VM analogous to VMWare’s VCenter or Microsoft’s System Center. This software promises to simplify the task of administering Linux guests running on z/VM.  To view part one of this series, click here.

Many customers who will be installing and implementing CSL-WAVE will no doubt have an existing z/VM and Linux for System z environment.  In this context the customer most likely will already have “gold master” Linux for System z images that are cloned to create new virtual machines to be used for applications and middleware that run the business.  CSL-WAVE easily integrates into an environment such as this by providing the capability to identify an existing virtual machine as a “prototype”.

How to convert a VM User to a "Golden Master" Prototype in CSL-Wave
Right Click on Guest and select “Convert VM User to Prototype”
Create Prototype from VM User Panel
Complete the “Create Prototype from VM User” Panel

Marking a virtual machine in this manner causes CSL-WAVE to ensure that the virtual machine will not be logged on to the system, and also to create a prototype directory entry to be used when creating clones of this virtual machine.

VM User is now Prototype
Your VM User is now a Prototype

Before designating a virtual machine in this manner, it is a good idea to execute the “init for wave” process so that all clones created from this base will already have that step completed.

Once this setup work is done, creating a clone from this base is as simple as right-clicking on the prototype icon and selecting “clone from this prototype”.

Select "Clone from this Prototype"
Select “Clone from this Prototype”

Before the clone process begins you will have an opportunity to specify the name for the new virtual machine, the z/VM password for the new virtual machine, and network connectivity for the new server.

Complete the "Clone from z/VM Prototype" Panel
Complete the “Clone from z/VM Prototype” Panel

The information provided will then be used by CSL-WAVE to create a series of background tasks to complete the clone process.  These tasks consist of creating the new virtual machine directory entry, and then copying the minidisks from the base image to the new image.  You can follow the progress of these tasks through the log viewer.

Work Unit Details
Work Unit Details for “Clone z/VM Guest” Task

When the clone process is completed, you will have a new server that can be activated and populated with applications and or middleware.  One step you might want to do at this point is to specify the group this new virtual machine should be part of.  The topic of projects and grouping is quite powerful and will be the subject of another blog on CSL-WAVE.

Assign Site Defined Group
Assign Site Defined Group

To activate the new virtual machine you simply right click on the icon and select Activate.   A window to confirm this and begin the process will be displayed.

Activate the new z/VM Guest
Activate the new z/VM Guest

With just a few clicks and a few minutes of time you have provisioned a new server all without knowing the many individual z/VM commands to execute the process.  When your new server is up and running it will already be ready for management by CSL-WAVE, so you will be able to gather performance data from it, as well as add resources when needed.

New z/VM Guest
New z/VM Guest