A long history
IBM's plan to pull iSeries closer toward the mainstream began in 1995, when the company switched it to a more widely used processor. But the server line already had a long history.
It began as the System/38 line that was launched in 1978 and the System/36 that arrived in 1983; the two lines were merged into the Application System/400, or AS/400, in 1988. Then in 2000, the systems were renamed iSeries, one of four lines within the over-arching eServer brand.
The processor switch in 1995, to IBM's Power processors -- used in the company's Unix server line -- was made easier by a previous decision to make the operating system independent of a particular processor. But only with this year's Power5 generation can the exact same hardware run three operating systems: Linux, AIX and i5/OS -- the core the iSeries operating system previously called OS/400.
The consolidation of lines under the eServer brand -- including the renaming this year of iSeries to eServer i5 -- reflected an effort to keep the groups from competing against each other and to consolidate engineering resources. The eServer i5 name parallels the eServer p5 label of the Unix server line, underscoring the gradual unification of the IBM server lines.
The Power5 server debuted on the i5 line first for two reasons, Zollar said. First, IBM wanted to show that the product family has strong IBM support, contrary to what competitors have said. Second, the new version has improved the underlying software for partitioning and for switching processors on and off as work demands change.
Adding Linux abilities -- and now merging with pSeries -- could hurt as well as help iSeries, though. It opens up the hardware line to new software options not available on the comparatively rare iSeries. On the other hand, that very openness makes it easier for iSeries customers to move away if they choose.
Indeed, the more that iSeries' value comes through the ability to run Unix and Linux, the more irrelevant its original operating system becomes. The ultimate risk: the iSeries becomes something else -- just another face in the server crowd.
An old dog learns new tricks
Fortlege, the iSeries customer from GH Young International, sees things from a different angle: adding new operating systems to iSeries has meant being able to add new tasks to the servers.
GH Young, which sells services that help companies deal with customs and other cross-border trade issues, has bought iSeries servers and their predecessors since the late 1980s and is expanding their use. Since then, it first added Integrated xSeries Architecture technology, which makes Windows a tightly linked extension to an iSeries machine.
Next came Linux, adding security, email, spam filtering and other tasks to the iSeries. And with a new Power5-based i5 520, the company will run and AIX version of software that previously ran on a computer with the SCO Group's Unix.
It's hard to say what fraction of i5-iSeries-AS/400 customers use Linux, but at user meetings, typically about 20 percent of attendees say they do, Zollar said. One quarter purchase the tightly integrated Integrated xSeries Architecture option, which now can run Linux as well as Windows.
The new Linux and AIX expansion options mean something of a culture clash for iSeries. That line is geared toward those who prefer to have a tightly integrated collection of hardware and software, whereas with Unix and its cousin, Linux, customers historically assemble a broad collection of software packages on their own.
"It's got a lot of east meets west," Zollar acknowledged. But it's worth it for customers, who typically use Linux for lower-end server tasks such as protective firewalls, he said. Linux users are moving toward higher-end applications such as databases, he added.
GH Young likes the new options. But the new expansion options available to iSeries customers is revealing in a less encouraging way to iSeries loyalists: much of the new software action is taking place somewhere else. It's telling that much of the new software that GH Young is using doesn't run on its traditional i5/OS.
"You can run a Web server on an iSeries," Eunice said, "but try to find yourself a Web programmer who has experience in that, or find yourself someone who's an expert in Microsoft Exchange and also AS/400? Good luck."
