The Possibilities of PASE

by Timothy Prickett Morgan

When I inadvertently misreported the demise of the PASE AIX runtime environment for the iSeries a few months ago during a bout with the flu, it got me to thinking. And thinking is always a dangerous--yet fun--thing to do. I have been thinking about runtimes and workload consolidation and how to get more stuff running on the iSeries, and I think IBM's PASE approach holds promise beyond the AIX runtime that it currently supports.

While I am a big fan of the very sophisticated hypervisor technology embodied in the Virtualization Engine for Power platforms--designed by IBM Rochester, perfected by IBM Rochester, and confiscated by IBM Austin to bolster IBM's Unix server line--these logical partitions now require the Hardware Management Console and are, in many respects, overkill for some midrange shops. This is particularly true for very small companies that don't have the extra couple of grand needed to buy an HMC, nor the skills to manage logical partitions. However, such customers often do have the need to run multiple operating system platforms--or more precisely, applications written for multiple operating systems. People care about their applications, not the platforms.

For instance, here at IT Jungle, we have a mix of FreeBSD and Linux Web servers, not because we need those different platforms, but because we think it is important to use different platforms and gain some experience with them. However, our tape backup software only works with Linux. Luckily, FreeBSD has a Linux runtime environment--invented by The SCO Group in the late 1990s, set free into the open source community, and then subsequently improved by that open source community. Because of the lxrun runtime, we can load our tape backup software's agents on FreeBSD even though, technically, FreeBSD is not supported. We also have an excellent email management system from Arial Software called Campaign Enterprise; it was relatively inexpensive, had lots of features we needed, but it was only available on Windows. If the open source Wine runtime environment, which allows Windows applications to run inside Linux--were more robust, I could have saved the 3 grand I spent on a separate Windows server. (It would have been better still had Arial Software ported its Campaign to Linux, but several years later, the company is still only selling a Windows version.

All IT shops face similar issues. They wish they had one magic server--what I called the Universal Server five years ago before IBM consolidated the pSeries and iSeries lines--that could run applications from many different platforms all on the same box. And to its credit, the iSeries as it is currently embodied represents the best effort to building the Universal Server that anyone has put on the market to date. To be fair, Unisys has consolidated two different mainframe architectures onto two very similar frames that each also support Windows and Linux onto single frames as well, and is well on its way to getting all four platforms on a single chassis. And Hewlett-Packard has HP-UX, OpenVMS, Windows, and Linux all running on its Itanium-based Integrity servers, and is getting ready to drop its NonStop environment on them as well.

Because of the complexities of logical partitions, I advocate runtime environments like PASE for small businesses. They just want to load their applications and manage them from inside OS/400. They do not want to have to manage full-blown AIX, Linux, or Windows servers, although in the case of the iSeries, they have to do that because Windows 2000 and Windows 2003 are only supported on the Integrated xSeries Server co-processors that can be plugged into the iSeries. While the IxS has been a great feature for the iSeries, a Windows runtime environment would have been a better option in terms of simplicity, and a native implementation of Windows running on the iSeries in logical partitions would have been better than the IxS (but more complex than many small businesses could handle for many applications).

So, the question is: Can the concepts behind PASE be extended to other platforms? The answer is a definite yes, but the probabilities that IBM will do this without customers clamoring for it are quite low.

Here are the possibilities that iSeries shops might find useful:

• A Linux runtime: This one is fairly easy, because there is a native implementation of the 64-bit, Linux 2.6 operating system available in the open source community. Basically, with such a Linux runtime, you can load Linux applications and use them from within OS/400 without the penalty of using logical partitions. Interfacing with OS/400 and DB2/400 are always issues from within PASE, but they are issues when talking across logical partitions, too.
• A FreeBSD runtime: There are probably not a lot of FreeBSD applications out there that are not also available on Linux. But a FreeBSD runtime would nonetheless be interesting for some people.
• A Solaris 10 runtime: You want to attack Sun Microsystems? The company is about to make it a lot easier. When Sun finally puts out the open source version of Solaris, called OpenSolaris, by the end of June, all of the pieces will be there for IBM to grab the Solaris source code and compile a runtime environment for a PASE-like Solaris runtime. Moreover, IBM could support OpenSolaris inside its logical partitions for high-end customers. And if IBM doesn't do the latter, it might be missing out on a big opportunity. Solaris customers love Solaris, not Sun and not their Sparc-based servers--just like OS/400 shops love OS/400, RPG, and DB2/400 and they could care less about IBM or the Power-based servers. Solaris on Power marries the best Unix platform with the best Unix iron. It is that simple. OpenSolaris on Power would be very competitive, even against Sun's future Sparc iron and the future "Jupiter" Sparc servers being designed by Sun in partnership with Fujitsu.
• A native .NET Common Language Infrastructure (CLI) and Common Language Runtime (CLR): When Microsoft created the .NET Framework and its Common Language Runtime, it didn't exactly open source them, but it did create a royalty-free specification that the open source Project Mono implemented for non-Windows platforms. Linux and NetWare vendor Novell has assumed control of Project Mono through its acquisition of Ximian in August 2003, right before it bought commercial Linux supplier SUSE. People are nervous about what Microsoft's lawyers might do to companies using Project Mono code, which has indeed created an environment where applications written in Microsoft's C# language can be run on Unix, Linux, and MacOS platforms. Because of Novell's takeover of the project, another group of open source developers have formed the DotGNU project. If IBM wanted to steer clear of any brewing battles between Microsoft and Novell, it could pitch in on the DotGNU project and move that implementation of .NET along. This could be the basis of a C# runtime inside a PASE-like environment on the iSeries.
• A Windows 2003 runtime: While IBM and Microsoft could work together to actually port Windows 2003 to the Power platform, even this would probably be overkill for many iSeries shops who might only want to run one or two Windows applications beside their OS/400 applications. That is why I still think that a Windows 2003 runtime environment might be useful--again, particularly for small businesses who don't want to manage Windows servers.

I raised all of these issues with several IBMers in recent weeks, and they were not exactly enthusiastic about it. One IBMer said he didn't want to be quoted anywhere near the suggestion that Windows might run on the iSeries, apparently because Microsoft gets testy about this. (You can just about guess what I would say to Microsoft about its attitude.)

"We have talked about doing other PASE-like things," said Jim Herring, director of iSeries product management and business operations, "but they are challenging to do because they are open source."

With a note of sarcasm, Herring reminded me that after IBM and Microsoft had parted ways on their common OS/2 operating system when Windows 3 was launched and Microsoft began work on the Windows NT server operating system, IBM put a Windows runtime environment inside the OS/2 Warp operating system for desktops and servers. This was an attempt to outmaneuver Microsoft, by supporting Windows and OS/2 applications on the same platform. "That didn't work out too well," he said. True. Keeping up with an environment that you do not control in a clone runtime is not easy--particularly if the people behind that environment don't want you to keep up. (I tested OS/2 Warp's Windows environment, and as emulation goes, it was not all that bad. There was just a big lag in compatibility and sluggish performance. Eventually, IBM's Windows license ran out, and it could not re-implement the runtime as Windows was upgraded to Windows 95, 98, and so forth.)

That said, there is a chance for just about anything to happen with the iSeries, if the technology is doable and the business case can be made. "Five years ago, product plans were cast in stone," explained Herring. "Now, we have free range to launch things or not launch things based on what customers want or need."

So, if you want an expanded set of PASE-like runtimes, what you have to do is ask IBM for it.