March 23, 2004

Logical Linux partitions on IBM's iSeries can benefit SMBs

Author: Stacey Quandt

Although the computer industry seems focused on the 64-bit battle between Intel's Itanium and AMD's Opteron, a more interesting 64-bit platform to watch is IBM's PowerPC.
Of IBM's two PowerPC platforms, the pSeries and iSeries, the latter, formerly known as the AS/400, is the one to watch. The iSeries, in combination with Linux, can drive new levels of productivity for end users.

Today there are more than 400,000 iSeries and AS/400 servers in use by more than 245,000 IBM customers in at least 100 countries. The largest concentration of iSeries and AS/400 customers is in Italy. According to IBM, customers in Europe, the Middle East, and Africa bought 46 percent of all iSeries and AS/400 machines sold.

Since IBM first released them on iSeries in 1999, logical partitions (LPARs) have become a key facilitator for application and hardware consolidation. IBM followed its first LPAR announcement with the introduction of Linux LPARs as an additional consolidation tool in 2001. A Linux LPAR can reduce the maintenance of multiple hardware and software platforms by enabling users to consolidate low-end Linux- and Windows-powered Intel servers. Up to 31 separate Linux environments can be supported on one iSeries server.

There are a number key technical advantages to iSeries as well. One of the most intriguing aspects of the iSeries is the ability to share processors, which allows users to pool processors in fractional increments and share them among partitions. A single
processor may be split among 10 partitions in amounts specified by an administrator, in increments as small as 10 percent of a processor. This is significant because an organization may not want to dedicate a single processor to a Linux partition, and instead may can choose to run a variety of workloads and even operating systems on a

The support for LPARs and dynamic resource provisioning on iSeries enables it to function as a hot-swap server. This puts pressure on the low-end Intel and midrange Unix server market. The ability for iSeries to run Linux, Windows, OS/400, and in the future AIX on the same server provides advantages that Sun, HP, and Dell cannot match.

The growing trend for small-to-medium enterprises to deploy ERP, CRM, and SCM applications on iSeries hardware is mirrored by customers' interest in leveraging native Linux partitions on iSeries to take advantage of server and workload consolidation. The addition of dynamic resource management to iSeries lets users allocate underutilized processors dynamically to support specific workloads.

There are several Linux distributions available for iSeries: Red Hat Enterprise Linux 3, SUSE Linux Enterprise Server 8, and corresponding SUSE-based distributions from Turbolinux and Conectiva. The current iSeries installed base of small to medium and regional banks tends to favor SUSE as the distribution of choice. Red Hat's slow awakening to the market relevance and revenue implications of supporting IBM's PowerPC platform leaves it at a disadvantage to SUSE, which has a longer history of running on iSeries and pSeries. However, the release of Red Hat Enterprise Linux 3.0 for Power and other architectures signals a change in its approach.

Customers turn to iSeries for alternative to legacy hardware and Intel systems

Existing iSeries customer references range from small-to-medium businesses to large customers. S2 Systems, Inc., an IBM iSeries solution provider, is the number two independent software vendor for electronic enterprise payment solutions. The company provides more than 400 customers in banking, retail, telecommunications, and travel with ATM and point-of-sale processing of credit and debit card transactions. S2 Systems' applications run typically in data centers next to the core banking systems.

Prior to moving to iSeries the S2 Systems electronic funds transfer system ran either on a legacy Stratus VOS platform as ON/2 or on Windows or AIX, HP-UX, or Solaris with OpeN/2, S2's third-generation enterprise payment platform. The uncertainty of legacy installs, the replacement cycle for new hardware, the ability to create significant cost
savings by consolidating the EFT functionality on the core banking hardware platform (typically zSeries or iSeries), the demands of faster time to market, and support of new channels were all drivers of S2's decision to seek an alternative to the Stratus platform and to leverage already installed iSeries and zSeries systems within banks. The
increasing adoption of Linux within the financial services industry and the reliability and scalability of iSeries are all factors that led the company to decide to port
OpeN/2 to an iSeries running SUSE Linux Enterprise 8 in 2004.

Two S2 customers who ran Tandem Non-Stop systems completed a five-year return-on-investment study prior to implementing OpeN/2 on zSeries. Both anticipated a savings of at least 50% over five years, due to the fact that the deployment of OpeN/2 on existing zSeries (and this would also apply to iSeries) would allow a customer to optimize their current investments in hardware, resources, skill sets, disaster recovery infrastructure, and 24x7 operations.

Memory Experts International (MXI), another iSeries user, is a small-to-medium business customer. The company manufactures biometric USB drives and network equipment connectivity devices. The company says it selected an iSeries as a means to consolidate a variety of white box servers onto a consistent platform and to centralize operations. The company's reliance on Accpac on Windows motivated MXI to choose a platform that could support Linux, OS/400, and Windows. The alternative was a clustered server with a mass storage array with Intel-based blades or rackmount servers. According to MXI the total cost of owership of iSeries is better than blades or an Intel rackmount system.


For businesses that decide to take advantage of iSeries LPARs and the ability to run workloads at the subprocessor level the first step is to assess how much processing power you'll require for each partition. Administrators who want to enable dynamic resource
provisioning on iSeries must be running OS/400 V5R2 on the primary
partition, which allows the kernel to boot in the secondary partition.

I recommend Linux on iSeries for organizations that want to consolidate workloads and servers, and for testing Linux patches and applications prior to deployment.

iSeries is an attractive option for organizations with workloads that require support for Linux, Windows, OS/400, and AIX, but that also want infrastructure simplification and the ability to consolidate workloads and reduce the need for additional system

Stacey Quandt is a principal analyst at Quandt Analytics, where she covers key market trends important to IT vendors and corporate users of Linux and open source technologies. Prior to establishing Quandt Analytics she was a principal analyst
at the Open Source Development Labs and an industry analyst at Forrester
Research. At Giga Information Group, a subsidiary of Forrester Research,
she created the firm's Open Source Research Competency and advised
Fortune 1000 customers with published research and tactical and strategic advice on Linux.


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