Linux on a mainframe is hardly a 'no-cost scenario'

Computerworld - Linux may be free, but users shouldn't overlook the costs associated with bringing it to the mainframe.
That's according to analysis delivered by Cambridge, Mass.-based Giga Information Group Inc. at last week's Share user conference in San Francisco.
For one thing, users planning to run Linux-based applications on IBM's zSeries mainframes should factor in the costs associated with getting enterprise-class support and maintenance services.
Depending on the kind of application and the number of CPUs Linux is running on, such costs can easily range from $25,000 to $30,000 annually, said David Mastrobattista, an analyst at Giga.
There's also the one-time cost associated with buying the zVM operating system - starting at around $45,000 - needed to run Linux on mainframe partitions. Optional zVM-related service and support cost about $11,000 per engine annually, Mastrobattista said.
On top of that is the software fees users need to pay if they want to optimize Linux application performance on mainframes using workload management and systems management software.
Keep Your Eyes Open
"People need to go into this with their eyes wide open. It's not a no-cost scenario just because Linux is free," Mastrobattista said.
Giga's warning comes at a time when Linux adoption on mainframes appears to be growing. Approximately 500 mainframe shops have some form of Linux applications running on big iron, with an estimated 20 sites running mission-critical applications, according to Giga estimates.
And IBM claims that customers such as Air New Zealand Ltd., Winnebago Industries Inc., Boscov's Department Stores and L.L. Bean Inc. have Linux applications running on mainframe partitions.
The opportunity to consolidate multiple Linux servers on a single box makes for better resource utilization and administration, said Gregory Hachigian, a manager of systems operations in the department of medical center computing services at UCLA Healthcare. And it has been so cost-effective that the organization is looking at consolidating more applications, he said.
The department is currently running two applications across 22 Linux servers in a single System 390 mainframe partition.
"We think the cost per server is going to become less as we keep adding more servers," Hachigian said.
IBM's efforts to make it as inexpensive as possible for companies to run Linux and other new workloads on mainframes have been contributing to the savings.
For example, the vendor offers an engine-based license that lets mainframe shops add capacity for running new applications without affecting other software fees.

Read more about Mainframes and Supercomputers in Computerworld's Mainframes and Supercomputers Topic Center.