Waiting for Linux to Pull Its Own Weight on the iSeries

In a few weeks, IBM will be delivering an update to OS/400, which has been i5/OS for the past year. Everyone knows its reputation for handling heavy-duty workloads by virtue of its impressive architecture and long list of applications. As an iSeries customer, you firmly believe that you get what you pay for. For instance, you get the capability to run multiple operating systems. In the past, OS/400 may have been enough. But as you look ahead, and certainly as IBM looks ahead, Linux could begin pulling more and more weight.

What can Linux do for you? Nothing if you disregard it as inconsequential to your business, to your organization’s bottom line, and to maintaining your status as an iSeries shop running your core business applications on OS/400. However, before you answer this first question, you really need to ask two more: Are you ready for Linux? And, is Linux ready for you?

Most would say: “I’ll get ready for Linux when Linux proves it is ready for enterprise computing.”

IBM brought Linux to the iSeries back in late 2000 to usher in the multi-platform era and get the proprietary-system monkey off its back. (Well, to be honest, IBM had already added enough Unix APIs to OS/400 in the 1990s to essentially call it a Unix variant, but whose counting.) From the get-go, Linux helped the iSeries gain some credibility outside its installed base by identifying the iSeries as a modern system. It was perhaps a mild tonic for the hardening of the arteries, to be sure. But just as importantly, it provided a weapon–albeit a small weapon–with which to do battle against Microsoft and its encroachment into data centers that formerly had been surrounded by a Big Blue wall. IBM has invested heavily in Linux. It has brought many of its most important business partners in on this as well. As we step into 2006, Linux in iSeries shops continues to pick up speed. But as you may have heard before, iSeries shops are not known for rapid change. They pick up speed like a locomotive rather than a jet plane. New versions of the OS/400 operating system take years to get implemented in even a quarter of the iSeries installed base. You can’t expect the Linux adoption rate to exceed OS/400 updates and still claim to have a sound mind.

But has Linux on the iSeries taken off as fast as IBM wanted it to? I would say that is doubtful.

“The typical iSeries customer is risk adverse,” says James Young, vice president of sales at Midrange Performance Group, an iSeries performance measurement, management, and capacity planning vendor. “Linux sounds like a PC thing to them and that means trouble.” Risk aversion could be the reason behind a slow adoption rate, whether the topic is Linux or almost any other technology, but Young also notes that from his conversations with customers about Linux “no one says ‘we’re not going to use it.'” OK. That means the door is maybe opened just a crack but not locked.

Linux continues to make a home in iSeries shops primarily because of applications that are devoted to infrastructure–file and print, Web serving, and Internet security. In some cases, it is exactly what IBM wanted it to be: a replacement for OS/2 and Windows and an integral part of server consolidation and infrastructure simplification projects. But to be more accurate, I’d say none of the irons in the fire could be described as glowing red hot.

The Road to Partition

What may surprise those without Linux experience is that most organizations are not loading Linux into an iSeries partition. They are running it on an Intel or, increasingly, an AMD box that is not integrated with the iSeries. This is not exactly what IBM had in mind. However, the cheap and easy access to X86 and X64 boxes on which to run Linux goes a long way toward making this the popular choice. You can also factor in the obstacle, real or imagined, that partitioning presents. It is a technology few iSeries shops have attempted to harness.

Partitioning has evolved considerably since its introduction in 1999. According to Craig Johnson, IBM’s Linux and AIX product manager, more than 30,000 partitions are being used to run Linux. Although there are no estimates of iSeries shops running Linux on X86 and X64 servers, it is widely believed to be many times more than those running it in a partition.

LANSA, one of the iSeries software vendors that does a lot of Web work, has customers using Linux. John Siniscal, LANSA’s president, estimates 20 percent to 25 percent of the iSeries shops his company deals with “have Linux on an Intel box somewhere doing something–most likely peripheral stuff like firewalls and Web servers.” In comparison, he says shops that are running Linux in a partition on an iSeries box are maybe one-third to one-half the number of those that run Linux on Intel. “Often, the Web serving is put on a Linux box. Apache on Linux is not unusual.” The application serving always remains on the OS/400 partition on the iSeries, but Siniscal predicts this will change. “It is inevitable that the mission-critical applications will come to Linux. It is a question of when, which ones, and in what sequence,” he says.

“The shops that have undertaken Linux projects so far have shown there are good Linux firewalls and Web servers,” Siniscal says. “As more apps come out that run on Linux and don’t run on OS/400, you will see more shops considering Linux logical partitions. If core business apps are running on OS/400, they are not going to throw that out, but I think we’ll find that downstream more people will be doing things in LPARs on the iSeries box.”

Although advances in logical partition technology have relieved some of the deployment pain, many shops have not even dipped a toe into those waters. Larger shops with correspondingly larger IT staffs are where these skills–as well as the most current operating systems–are found, but Johnson contends the road to partitioning is not so intimidating that only the strong survive.

There are a couple of ways to do partitioning on the new Power5-based systems, he says. The Virtual Partition Manger, a function of i5/OS, is specifically for implementing a single Linux partition. For adding multiple partitions, including AIX, the Hardware Management Console (HMC) is the required tool. The HMC has taken some hits for its own degree of complexity and idiosyncratic behavior, but if Linux partitioning is on your to-do list, check out this option.

“It is easier to create and manage partitions compared to when partitioning was introduced,” Johnson says. “The value and functionality of partitioning has increased significantly. When partitioning was first introduced, there were dedicated processors in each partition and a partition had to be shut down to move resources. Improvements along the way led to dynamic movement that allowed partitions to stay up while moving resources. Then, micro-partitioning was introduced so fractions of processors could be applied. And, with Power5 came automatic processor movement that allows movement between partitions based on demand. This has been a significant area of investment for IBM. It increased the function and the ease of use.”

Integration, Consolidation, and Economic Considerations

In terms of building a Web site that depends on the iSeries for much of its data, better integration comes with running Linux on the iSeries rather than in a standalone Intel box, Young says. Yes, processors, memory and disk storage behind iSeries partitions are more expensive than the equivalents on Intel machines, but the long-term total cost of ownership (TCO) favors the iSeries. His experience also comes from customers that are primarily bigger shops with larger staffs. He sees some moving away from RPG and building platform-portable applications (C, Java, .NET, and other programming languages) that run under Linux.

Server consolidation continues to be a popular strategy in IT departments worldwide as they look for methods to drive down costs and gain scalability. Vision Solutions, a disaster recovery and high availability vendor, has been involved with IBM and mutual customers that are clustering applications on Linux for availability. According to David Wegman, vice president of marketing at Vision Solutions, these iSeries customers are looking at Linux as an alternative to Windows. Based on the feedback he gets from IT managers at large organizations, Wegman says, “Linux as a low-cost alternative to Windows does not seem to be conducive to running on an iSeries. As long as Linux remains an edge-type product–doing print, file, and Web serving–it will not likely run on the iSeries.” Wegman says Linux is more cost effective when running on an Intel server in these situations. “As Linux becomes more important in terms of applications and database,” he says, “it will be more likely run an iSeries. At the end of the day it may all come down to economics. How much does it cost to run Linux on an iSeries versus an OpenPower, Opteron, or Xeon box? There is a benefit to running it on the stable iSeries box, but that is weighed against costs. Until those numbers come into balance, it will be tough to justify running Linux on the iSeries.”

Will Linux Light an iSeries Fire?

A few weeks ago, we published an article about running AIX on the iSeries, which showed business applications, ISV solutions, middleware, and database applications as the main reasons iSeries shops are interested in partitioning for AIX. Here we have a different set of customers. This time they are attracted to an operating system that is conducive to infrastructure applications, file and print, Web serving, and network security. The amount of overlap, says IBM’s Johnson, comes primarily from AIX users thinking in terms of partitions for Linux rather than the other way around.

What IBM needs to do is expand its ISV program to bring more core applications from both the Unix and Linux side into the Power market. This could help both pSeries and iSeries capture new workloads. Even though IBM officials are happy to report more than 1,000 Linux applications are available for the Power platforms, this list needs to have some teeth in it. It’s easy for IBM to say its infrastructure simplification offerings–AIX, Linux, and Windows–continue to grow because they are so small that growth is almost inevitable. Real growth comes when adoption rates break out of the single-digit category.

It’s optimistic to say there is a rush to put Linux on the iSeries. Looking on the bright side, it’s good to see iSeries companies starting to rely on it for a number of infrastructure and middleware uses, even if the majority of organizations choose to run it on Intel. It’s also encouraging to see a company like SAP port its core ERP applications to Linux, which it did a number of years ago. As soon as more core applications can be found on Linux, interest from the iSeries customers is likely to increase. And as logical partitioning becomes less complex, the skills gap will close making Linux easier to deploy on iSeries. And, who knows, if IBM erases the economic barrier that pushes customers to running Linux on Intel, that would be a good thing for iSeries with and without Linux in the picture.