Two years after a handful of IBM programmers in Germany first ported Linux to the IBM S/390, thousands of IT shops have downloaded free versions of the software from the Web. And more than 300 of these, according to IBM, are serious enough about the platform to have purchased hardware or support contracts from IBM specifically for Linux on the mainframe.
The level of interest has taken many by surprise, including IBM itself. "A year ago, honestly, we did not expect it to take off as it did," says Joann Duguid, IBM's director of Z-series Linux.
"Linux has been a huge breath of fresh air for the mainframe," says Giga Information Group analyst David Mastrobattista. "It's now politically correct to be talking about mainframes again in the data center."
The interest in Linux on the mainframe has helped boost mainframe sales, according to both analysts and IBM itself. IBM has seen double-digit growth for the Z-series mainframe over the last four quarters, and "attributes a large part of that to Linux," says Duguid. Mastrobattista says he would not be surprised to see the use of Linux on the mainframe double this year.
Much of the interest in the platform is coming from companies which -- despite having spare cycles on their existing mainframes -- find themselves continually adding new Unix, Linux or Windows-based servers to their computer rooms to handle every-day computing chores like file, print and Web serving or email.
Running Linux under the VM operating system, these firms are discovering that they can bring up an essentially unlimited number of "virtual servers" on one mainframe, allowing them to consolidate many applications onto one system. That makes backup and administration much simpler and eases the pressure on crowded computer rooms which are running out of floor space, all the while taking advantage of the traditional high reliability and tremendous scalability of the mainframe.
Many of these companies are finding that the move is extremely simple. That was the case at Securities Industry Automation Corporation (SIAC), which runs the computer systems for the New York and American Stock Exchanges.
Last summer, SIAC moved a homegrown application off of Sun SPARC servers and onto an IBM zSeries mainframe running Linux. The program uses the open source Sendmail email program to deliver daily reports to Wall Street brokers on their stock transactions. According to IBM, the port took SIAC programmers only two-and-a-half days.
Slashing Application Costs
Another big draw of Linux on the mainframe is money. While Linux for the mainframe, and technical support, is available from companies like Red Hat, SuSe and Turbolinux, it can also be downloaded for free from the Web. And some companies, like recreational vehicle-manufacturer Winnebago Industries, of Forest City, Iowa, are discovering that Linux on the mainframe can slash the cost of application software licenses as well.
Two years, when Winnebago began looking for replacement software for its obsolete public domain email servers, which dated back to the 1980s, it turned first to Microsoft's Exchange Server. But the cost -- approximately $100,000 -- sent the firm looking for other options.
Last March, Winnebago began installing the Bynari Insight Server, from Dallas-based Bynari Inc., on its IBM Multiprise 3000 mainframe, under Linux. Today, Winnebago's 700 or so salaried employees, who use Microsoft Outlook as their email client, rely on the system for email and messaging, at a cost that Dave Ennen, Winnebago's Technical Support Manager, calculates to be roughly one-quarter of the price of buying Microsoft Exchange.
Winnebago had plenty of time to get comfortable with Linux on the mainframe. It first downloaded the software in September 2000, from the Web site of Poughkeepsie, N.Y.'s Marist College, which has served as a central liaison point for mainframe Linux. Since then, it has been using its mainframe and Linux for domain name serving, NFS, Samba and other utilities.
The success of those applications is leading Winnebago to consider moving other programs to the platform. "I'm done buying servers for a while," says Dave Ennen, Winnebago's technical support manager, "as long as I can find applications that run under Linux."
Those applications appear to be coming. IBM's WebSphere application server has run on the mainframe under Linux for more than a year, while SAP AG's mySAP.com e-business platform will be available in March. BMC Software's Mainview mainframe management tool was released in December, and Computer Associates has a number of products for the platform either in the pipeline or already out, including its flagship Unicenter data center management software.