For quite some time now, IT budgets have been increasingly tight. Managers and systems programmers are being told repeatedly to reduce costs. IBM has generated considerable interest in the Linux (and particularly mainframe Linux) operating system as a way to do this. Unfortunately, the press has touted Linux as “free,” as in no cost, but it’s more proper to view it as free—in that it allows users many freedoms. This confusion has resulted in many people being told to investigate mainframe Linux with absolutely no money to spend on the project. That’s feasible for proof-of-concept-type projects, but production systems that require system tools, maintenance, and support are another matter. If the proof of concept shows acceptable ROI, a business case can be made to spend money to save money.
This article surveys commercial and no-cost Linux distributions available for the mainframe, identifies the terms for evaluation and support options, and offers some insight into the characteristics of the various distributions.
Linux/390 Distributions Available in North America
The very first was what is now called Marist File System: The installation consisted of unloading a “tarball” and configuring the network. Soon after the release of this system, Millenux in Germany made ThinkBlue available for S/390, and then followed up with a 64-bit version for zSeries. While both of these distributions were and still remain available for no cost, they’re also obsolete and shouldn’t be used, since there are more current distributions available.
When IBM decided to actively market Linux, it signed agreements with three Linux distribution providers: SUSE, Red Hat, and Turbolinux. The agreements required the partners to provide Linux distributions for all of IBM’s hardware lines, including S/390 and zSeries. Since then, Turbolinux has been acquired by a Japanese company and no longer serves the North American market, nor do they produce a mainframe Linux distribution. In terms of commercial Linux distributions for the mainframe actively being sold in North America, that leaves only SUSE and Red Hat.
SUSE was the first company to market a commercial Linux distribution for the mainframe. As a result, it garnered nearly the entire early market share and still maintains quite a lead over its competitor, Red Hat. Due somewhat to fortunate timing of Linux kernel releases, they’ve been producing newer versions sooner than Red Hat by several months.
SUSE has also been receiving important certifications for its SUSE Linux Enterprise Server (SLES) platform from companies such as SAP, Oracle, and IBM. Beginning with SLES7, SUSE began to position SLES for the enterprise market. It produces less frequent major revisions, providing maintenance and support for years beyond initial general availability, etc. SUSE also continued developing and supporting its non-enterprise versions, SUSE Personal and SUSE Professional. Novell acquired SUSE in January 2004, giving SUSE Linux access to Novell’s more extensive sales channels and more credibility in the North American enterprise computing market.
In the U.S., Linux is nearly synonymous with Red Hat. As a result, when Red Hat made its mainframe distribution available, many people wanted to give it a try if only because they were already running Red Hat on Intel hardware and wanted to standardize on one distribution. Not long afterward, Red Hat changed its business model to focus entirely on the enterprise market, dropping development and support for its “consumer” versions. This alienated some of the company’s long-standing consumer version user base while attracting others who run businesses and want to work with suppliers that understand what a business needs. Although still struggling somewhat to achieve that understanding, they do appear to be working toward it. The transition has been difficult for both Red Hat and its users, but appears to be producing the better profitability that Red Hat needed and desired.
Fortunately, for everyone with no money to spend, there are several good, no-cost Linux distributions for S/390 and zSeries. Listed roughly in the order they became available:
- Debian, one of the oldest, non-commercial Linux distributions with a very large and dedicated developer community, is available for 31-bit systems and a 64-bit version is under development.