iSeries rises to conflicting demands

Summary:IBM's iSeries will never be IBM's most exciting range of servers, but it is destined for great things, according to one of its architects

While other systems hit the headlines, IBM's iSeries, formerly known as the AS/400, just carries on doing what it does best. Segment manager for enterprise technologies on the iSeries, Amit Dave, spoke to ZDNet UK about the future for IBM's most business-like servers. The iSeries is benefiting from IBM's efforts to share technologies across all its servers, and Dave has been in charge of this for the iSeries, bringing eLiza to the system, along with logical partitions, storage networks and grid computing. Yet while IBM servers become more alike, Dave believes iSeries is going to maintain its own identity. He disclosed his ideas to us. Technologies spreading
The mainframe division is the source of most of the technology which IBM is sharing across its servers. This policy was instituted by former IBM president, Lou Gerstner, and operates on every level. In manufacturing, systems are made from common parts as far as possible. "Eight years ago, the machines did not even use the same power supplies," said Dave. "It doesn't make sense for the company to have four production lines and not share a bag of parts. Under Gerstner, that mentality got crushed." Now, IBM production lines can change easily between making mainframes and other servers, since so many of the parts are common. The sharing of software is more exciting though. The biggest developments in iSeries software have been items brought across from the mainframe world, but the iSeries' own developers have been keeping their end up. The most recent big iSeries software announcement, version 5 release 2 (V5R2) of the OS/400 operating system, was launched in April. "This was the largest release to come out of Rochester [Minnesota, the home of the iSeries]," said Dave, "both in the number of lines of code and the richness of features." The new release is the foundation of future efforts to enhance the middleware on the iSeries, he said. In the future, "we want to be the flexible server of choice," he said. Among the additions to OS/400 was single sign-on to applications on multiple iSeries servers. This is Enterprise Identity Mapping (EIM), an eLiza initiative, based on the widely used Kerberos authentication system and the directory standard LDAP. As an eLiza project, EIM is going to show up on other systems. LPAR, the key to consolidation
The release extended the use of logical partitioning (LPAR) in iSeries. "Years ago, you would not have been allowed to take LPAR from the 390 [mainframe] to the iSeries," said Dave. "But we did it." Rochester is leading development on LPAR beyond the mainframe, according to Dave. "Technology exchange is happening, and we are seeing the rewards." LPAR lets the user run multiple operating systems, or multiple versions of the same operating system in separate partitions on one machine. It is fundamental to the future of the iSeries, said Dave. For one thing, this allows consolidation, letting users run multiple operating systems without having to dedicate a server to any of them. This is particularly important if one operating system is required for some non-critical task which runs at intervals, such as a month-end accounts run. Potentially, it could also help if the company has an application which needs Oracle instead of the iSeries' native database, DB2. It is also useful within one operating system, if the user has applications which only work on certain versions. Older versions of the OS can be kept going while applications are migrated, and newer versions can be tried out without risking the whole system. However, so far the only other operating system to run in an LPAR partition is Linux. Despite leaks that implied that V5R2 would support IBM's own Unix version, AIX, in LPAR, all that came out was a "statement of direction" (SOD) to say it would happen. These statements are IBM's way of telling you something is coming in about 18 months time, so users must wait till 2004 for AIX partitions on their iSeries systems. Another slight disappointment was IBM's failure to allow 255 partitions. This, again is promised for the future. LPAR first arrived on the iSeries in 1999, but at that stage it was static, with partitions set up "in stone", and only on certain systems. Dynamic LPAR, which lets the administrator tune the amount of resources given to each partition, arrived in May 2001. "There has been tremendous uptake of LPAR," said Dave. " We want 100% deployment, and it is now 45%." This rate of use is impressive, given that the feature has only properly been available for a year, and requires iSeries users (renowned for their conservatism) to move to release 5 of the operating system. "We have yet to see anyone get upset by it." Elsewhere in IBM's range, the AIX-based pSeries also has LPAR. Both iSeries and pSeries have the same Hypervisor tool to manage the partitions.

Topics: Servers

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