Linux on Mainframes - an IBM update

Many Linux proponents appear to equate Linux with the use of industry standard X86 systems. IBM demonstrated that its Mainframes are a growing portion of the market.
Written by Dan Kusnetzky, Contributor

IBM presented an update on Linux on its mainframe line of computers. It was refreshing to learn about the success Linux has been having outside of the realm of industry standard X86-based systems. Here's a quick summary of the session.

Growth of Linux on IBM System Z

The shipments of IBM's Integrated Facility for Linux (IFL) increased 76% between the second quarter of 2010 and the second quarter of 2011.

IBM measures use of its mainframe systems in millions of instructions per second (MIPS). Linux installations consumed 26% more MIPS between the second quarter of 2010 and the second quarter of 2011. Nineteen percent of the IBM System Z MIPS are deployed to support Linux as of the end of the second quarter.

If we look at the overall installed base, 34% of IBM's System Z customers have installed the Linux facility. This includes 63 of the top 100.

At this point, more than 3,000 Linux applications are available on this platform.

z/VM 6.2

IBM's virtual machine facility has a very long track record of supporting production workloads. The major improvements offered by version 6.2 was support of clustering for up to four z/VM instances hosted on mainframe logical partitions (LPARs). These LPARs can be hosted on a single machine or distributed over several machines. Linux guest environments can be relocated from one LPAR to another without disruption of the workloads being supported.

Variable pricing model

IBM also launched an interesting pricing model for Linux on IBM System Z that mimics the pricing used in the wireless telephone market. Customers basically subscribe to a specific computing capacity and pay a monthly fee for its use. If they use more than the capacity that they've subscribe to, they would incur variable fees based upon actual usage. The customer may change the capacity subscription to increase or lower the usage entitlement.

It appears that this pricing model is intended to make it possible for customers or service providers to operate using a private cloud model.

Snapshot analysis

A common assumption I've observed when speaking to those using Linux or thinking about a Linux deployment is that industry standard systems are always the best choice of physical platform. The growth in IBM's System Z Linux deployments demonstrates that the mainframe may be a strong option for some workloads.

Mainframe deployments were seen to offer lower cost of ownership in past studies due to the powerful management and virtualization tools the operating environment supported. It appears that IBM has been working hard to improve the performance of its systems in this area.

Organizations would be wise to consider the mainframe option when designing their Linux-oriented Web, virtual or cloud computing environments.

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