Mainframes Are Still A Mainstay

Linux has been important to the mainframe because it lets companies run applications that they either couldn't run or which were too expensive to run on a mainframe, such as E-mail, firewall, file-and-print, and Web-server applications, says Boas Betzler, a senior technical staff member with IBM's eServer development team.

Wisconsin Physicians Service Insurance Corp. is running 26 virtual Linux servers on its zSeries 900 mainframe to manage a variety of applications, including its domain name server and Apache Web server. The nonprofit insurance company can run Linux on the mainframe for 40% of what it would cost to run the same apps on any other server and operating system, says Randy Lengyel, senior VP of management information systems. Plus, the business can increase or decrease the number of virtual Linux servers to reflect seasonal traffic, which peaks at the end of each year during member enrollment. "We can create single-or two-processor servers in the virtual world on the mainframe and designate the level of utilization on each Linux server," Lengyel says.

Wisconsin Physicians Service needs this kind of flexibility. In the past four years, the amount of health-care claims it handles annually has jumped from $840 million to $7.5 billion. The company still runs its core claims systems and operating system on the OS/390 side of its mainframe but has partitioned the machine so it can run the legacy and SuSE Linux operating systems side-by-side. Now it's waiting on a Linux-based version of PeopleSoft Inc.'s accounting and human-resources software to run on the mainframe for more savings.

Linux has made logical partitioning and server virtualization on the mainframe inexpensive. A feature that continues to set mainframes apart from high-end Unix and Windows servers is the mainframe's ability to run multiple applications and operating systems on the same server. Linux has the added ability to dynamically reconfigure partitions for those applications without server downtime, a capability known as server virtualization. "With virtualization, if a server fails or peaks out in capacity, the server creates a new virtual server," IBM's Lechner says.

The capability to divide and allocate resources brings with it systems-management challenges that IBM addresses with autonomic applications that let the mainframe configure, repair, tune, and secure itself. "We're still in the early stages of autonomic computing," says Tom Hawk, IBM's general manager of grid computing. "We as human beings would need three full-time doctors with us at all times if our bodies functioned at the same level as autonomic computing today."

Early next year, IBM plans to make available on zSeries, pSeries, and iSeries servers autonomic enterprise workload-management software that automatically allocates and reallocates system resources for different applications as needed. IBM earlier this month delivered dynamic logical partitioning capabilities to its pSeries Unix servers with the latest version of AIX 5L. Version 5.2 lets system resources, including processors and memory, be assigned to independent partitions without rebooting the system. Similarly, IBM's x440 Intel-based server lets users add more processors once the server has been installed, much the way users can order additional capacity on demand for their mainframes.

Still, not all mainframe customers see a future in IBM's zSeries. Sabre Holdings Corp. revealed earlier this month that it has begun to migrate its airfare-pricing application from its IBM mainframes to Hewlett-Packard NonStop servers. The migration is the first part of a four-year program to switch Sabre's pricing, scheduling, and seating system from IBM's transaction-processing technology to Unix using relational-database technology.

NonStop servers will cut the cost of running Sabre's airfare-pricing application by about 40%, says Craig Murphy, Sabre's chief technology officer, though he wouldn't provide specific figures. Similarly, Sabre rival Galileo International, a subsidiary of travel-services company Cendant Corp., in May began replacing part of its IBM mainframe infrastructure with SunFire 6800 servers and Solaris 8 for its GlobalFares airfare-pricing system. It's a move Galileo says will save the company tens of millions of dollars in programming and hardware-maintenance costs.

The key to the mainframe's relevance moving forward is for IBM to continue to keep costs down while delivering higher performance. This kind of progress makes a mainframe "a purchase that's easier to defend," D.H. Brown's Partridge says. "People are confident they won't wake up and read the headline one morning that IBM is abandoning the mainframe."