Low-cost Linux revives IBM mainframe (again)

IBM Corp.'s decision to offer a Linux-only mainframe -- at 90% less than the cost of its flagship box has had the...

intended effect, research now shows.

For more on Linux in the data center: Linux and virtualization create a shift in the data center IBM shrinks the data center with Linux

"Linux is a key to the IBM mainframe new-workload strategy," said Charlie Burns, a vice president of Westport, Conn.-based Saugatuck Technology Inc.

The target for IBM's Linux-on-the-mainframe push: greater adoption of Linux among large data centers. ,

So far the approach has worked. According to Saugatuck's research, in 2007 approximately 25% of all System z capacity being shipped to customers is designated for Linux workloads. "These measures of demand are evidence of the growth in usage of mainframes for both traditional and new, nontraditional workloads," Burns said.

The price is right too. Cost could make the mainframe an attractive must-have alternative for IT managers who previously had not considered it, Burns said. When purchasing or upgrading a System z, for example, a customer can request one or more processors for exclusive use by workloads running on Linux. These Linux-only processors are priced approximately 90% lower than a processor for a traditional mainframe workload. The 90% number may seem unbelievable, but it is exactly what IBM offers for a line of specialized mainframe engines. There are also specialized database and Java application engines offered at a steep discount. "It is an interesting phenomenon that IBM would discount that much," Burns said, "but they are a company that is very interested in getting people to understand that they believe this is a great platform."

"The benefits of such migrations are improved workload management, performance, availability and security, coupled with reduced costs for electrical power, cooling, floor space and support staffs," he said.

Other benefits include the mainframe's ability to "upgrade in place," Burns said. For example, with System z, data center managers can install additional capacity and/or upgrade to a newer technology without adding another server. "For rapidly growing workloads like [Software as a Service], this can yield substantial savings, especially since capacity can be added dynamically and nondisruptively as the workload grows," he said.

Additionally, Saugatuck research has shown that mainframes provide higher levels of security. In 2003, System z was certified as Evaluation Assurance Level 5, the highest-level security certification of any server platform. The Evaluation Assurance Level (which ranges from EAL1 through EAL7) of an IT product or system is a numerical grade assigned upon completion of a Common Criteria security evaluation, an international standard created in 1999. IT managers can also opt to install more than one Linux processor and, with that configuration, have a production server, development server, backup server and database server all consolidated on the same box. "From an IT manager's perspective, that's heaven," he said.

An elementary roadmap Charlie Burns, vice president of Westport, Conn.-based Saugatuck Technology Inc., recommends that every company with more that 20 x86 servers should performconduct a thorough evaluation of existing workloads and servers with the following steps in mind: 1. Those x86 servers that yield the largest savings should be migrated to the mainframe first (i.e., servers with unique infrastructure support requirements). 2. Those x86 servers with the lowest utilization should be migrated earlier. 3. Assets with an upcoming compelling event (that is, a need for a capacity upgrade, a lease expiration, etc.) should be migrated before incurring the expense. 4. User departments should aggregate x86 servers and workloads to create buy-in. 5. The oldest x86 servers should be migrated earlier. 6. Focus on real estate by freeing up contiguous raised-floor space or eliminating sites as early as possible.

That's because many Windows applications will "operate" on a Linux platform, but once they are migrated over, the vendor that sold the application will no longer support it. If IT managers decide to migrate, they must weigh that risk, Burns said.

"If you are not currently using Linux then you have to convert to it," Burns said. "Converting workloads from Windows to Linux isn't impossible but it's a formidable task. As with any migration, you'll also have to make the transition with your support staff; what they're trained on, what tool they will use, how they'll back up the database, etc."

Despite these concerns, however, Linux is still widely viewed as a mission-critical platform and will control 50% of all mission-critical operations in the data center by 2011, according to a Saugatuck report published earlier this year.

"By adopting [the specialty-engine approach], the IBM mainframe platforms have succeeded in a key area where non-mainframes have failed. The approach enables non-mainframe workloads to benefit from many of the capabilities which had been exclusively experienced by traditional mainframe workloads," Burns said.

Email Jack Loftus with your comments and suggestions.