Features Galore Inside i5/OS V5R4

Published: January 31, 2006

by Timothy Prickett Morgan

As we have all been anticipating, the latest iteration of the OS/400 platform, i5/OS Version 5 Release 4, makes its debut today, and will begin shipping on February 14 with the new System i5 Power5+ servers that IBM also announced today. IT Jungle has been previewing many of the features of i5/OS V5R4, so some of this will be familiar to you. IBM has given us an initial briefing on the new software, but it will take some reading of announcement letters and Redbooks before all the details will be known.

But before we get into all of that, there is one great thing about i5/OS V5R4 that is not in the spec sheets: You do not have to use it, even on the new System i5 servers. IBM is still selling i5/OS V5R3 for those customers who are not ready to take on a new release of the OS/400 platform or whose applications may not yet be certified for the new release. "Everybody is delighted about this," says Ian Jarman, the System i5 product manager who has been the voice of so many iSeries product announcements over the years. "It's not that people do not want to go to V5R4. It's just that they can't all necessarily get there immediately."

Letting customers move at their own pace is a wonderful thing, especially in contrast to the past, when so many AS/400 and iSeries upgrades required customers to get new operating system software when they acquired the latest hardware. This is, I think, one of the things that has held down sales of AS/400 and iSeries servers, even if it has had the benefit of keeping customers more current on their operating system releases than they might otherwise be. I think that customers left to their own devices would probably just as soon skip every other software release and only make version upgrades when absolutely necessary.

IBM is giving customers fair warning that the new i5/OS V5R4 will be the last operating system supported on the iSeries Model 270, 820, 830, and 840 machines as well as on the SB2 and SB3 application servers that are based on the same S-Star and I-Star processor technology. i5/OS V5R4 also runs on any Power5 or Power5+ i5 server, including the iSeries i5 models from 2004 and the new System i5 machines launched today (see "The iSeries Gets Power5+ Chips and the New System i5 Moniker" elsewhere in this issue of Four Hundred Stuff). i5/OS V5R4 is also supported on Power4-based iSeries 800, 810, 825, 870, and 890 machines. However, earlier machines, like the Northstar-based AS/400 720, 730, and 740 servers, cannot run i5/OS V5R4.

Jarman warns that the next release of i5/OS--which could be called i5/OS V6 if it comes to market concurrently with Power6-based servers in 2007--will run on Power4, Power4+, Power5, and Power5+ servers, which means iSeries 800, 810, 825, 870, and 890 machines, and i5 520, 550, 570, and 595 machines--and, of course, Power6 servers if they are announced together. It could be that IBM does an interim release to add new functionality to V5R4, perhaps to add partitions that allow workloads to be moved from one physical machine to another. AIX 5.4 is expected to get such functionality in the second half of the year through a maintenance release, so why not i5/OS, too?

IBM has made another packaging change with i5/OS V5R4, which I want to explain before going over the biggest features in the new release. Starting with V5R4, all languages will be supported in all geographical regions. While OS/400 and i5/OS has always had excellent multi-language support, certain languages were only available in certain regions. With i5/OS V5R4, customers can get multiple language support for i5/OS no matter where they buy the i5 machine or plop it down. For example, a company based in Asia that uses one of the double-byte character languages (Chinese, Japanese, or Korean) will be able to use those languages in i5/OS distributed in North America and Europe, and IBM will support it in those areas, too.

As we have previously reported, V5R4 has a new 32-bit Java Virtual Machine that has a smaller memory footprint than the 64-bit "Classic JVM" that IBM Rochester created for the iSeries many years ago. While this 64-bit JVM has excellent performance on large SMP servers that exploit 64-bit main memory addressing, the rest of the industry--including other IBM server divisions--are using a much leaner 32-bit JVM. The new 32-bit JVM will be bundled with WebSphere Application Server 6.1, which is expected to be released later in 2006. The 64-bit Classic JVM was recently extended to the JDK 1.5 level, and this future 32-bit JVM will hit that JDK level, too. It is unclear if this new JVM is going to be a base option right now in V5R4, regardless of what goes on inside WebSphere, but this seems likely.

IBM is quite excited about the new Database OnDemand Performance Center, which has been added to iSeries Navigator to help DB2/400 database administrators do a better job of managing the queries that customers launch on the iSeries. The resource governor, which will keep SQL queries that try to eat all the system resources from hogging the machine, is probably going to be very popular feature. Many OS/400 shops do not allow managers to run complex queries during the business day because of the resources they consume, but the governor in the new database administration tools will allow administrators to let queries run and better serve users without affecting the performance of transaction and batch systems on the same server. The tool also helps admins maintain indexes and rebuild them if they get corrupted as well as monitor the performance of SQL queries. IBM has also boosted DB2/400 so it can support 2 MB SQL statements, 128-byte column names, up to 1,000 tables in a query, and up to 10 million objects in a single journal. These database features are part of i5/OS V5R4--you don't have to pay extra for them.

IBM is also touting improvements in the Control Language (CL) scripting language with V5R4. While CL was enhanced with V5R3 almost two years ago--has it been that long?--Jarman says that the new pointer data type and based CL variables will be hot items that are "going to open up new possibilities" for CL and will get admins and programmers alike excited. CL will support simple subroutines, which cuts down on code repetition in CL programs, and now CL can also hook into a lot of the application programming interfaces that ship in i5/OS programs and service programs. In V5R3, IBM added support for integer CL variables, DO loops, a SELECT case construct, and passing parameters "by value" to called procedures.

Administrators and programmers alike are also going to take a shining to several new backup options in i5/OS V5R4. The virtual tape support feature will be extremely useful, in that it will allow all SAV commands to back up data to virtual tapes stored on disks rather than on actual tapes (which are a lot slower). The virtual tape feature is enabled on system saves and can span multiple libraries; it will not, however, restore i5/OS licensed internal code or the i5/OS operating system itself. This virtual tape server in V5R4 can be integrated into IBM's BRMS hierarchical storage software, but does not require it; you access the virtual tape server though iSeries Navigator (presumably to be renamed System i5 Navigator?). IBM is also, as we previously reported, allowing V5R4 to save and restore spool data files, which is important since when a system crashes, the spool files go with it and they have to be regenerated after a restore. Companies used to keep images of spool files, but now they can archive and restore the real things, which will allow them to be put to immediate use. Finally, IBM has enabled parallel saves (which speed up archiving performance) on the Integrated File System after having already done this for DB2/400.

On the high availability front, the base cluster services inside V5R4 have been extended so the synchronization of environmental objects such as user profiles, system values, job descriptions, and such, are transmitted between source and target machines in a cluster by i5/OS itself in a standard way. This is akin to IBM adding native journaling support to OS/400 V4R4 many years ago, which all of the high availability software vendors then tapped. This feature is called administrative domain support, and it does some of the work that high availability software vendors have had to do on their own with their products. There are a number of other high availability enhancements, which we will go through in detail after we talk about them a little more with the HA software vendors and IBM.

Finally, if you are running so-called "patched" or "system state" programs, like the old Fast400 governor buster, V5R4 is not going to let you do this any more. As part of the security enhancements in i5/OS, the software will not let programs go down into the microcode layer anymore. By letting independent software vendors do this, IBM left itself open to the whole Fast400 debacle and also left open a potential security risk on its AS/400, iSeries, and i5 servers. Now, that hole is plugged. Jarman was kind in describing why this was happening, and he didn't bring up Fast400, which has gone out of business after its founder settled a lawsuit with IBM late last year. "There were some ISVs who wrote in microcode for good reasons, and we have been helping them with APIs so they are not disrupted by this change."