3.4 Six reasons to run Linux on the mainframe

Many more benefits of running Linux on the mainframe have crystallized than were expected at the time of the first proof of concept. In our talks with companies that use Linux on the mainframe, we have come across more benefits than we can list here. However, let us look at some of the most important ones. All of these will be discussed in greater detail later in the book.

Linux on the mainframe meets several needs of mainframe-based enterprises today:

• Responsiveness.

  Many of the Open Source tools and applications that exist for Linux have become available on the mainframe. You can also test and use new functions earlier (in most cases) on Linux. You can try them out and promote or abandon them, depending upon the result of your tests.

  If a workload is broken up properly and distributed so that the right pieces of work are on Linux, time-to-market can be reduced. Securely isolated Linux images can be set up with ease, together with virtual communications that can be dynamically changed. This flexibility also adds to the time-to-market benefit.

• Close integration.

  Today's applications are typically multitiered, with the back-ends firmly rooted in z/OS and other platforms vying for the other tiers. Linux makes it possible to move the middle-tier close to the z/OS mainframe back-end, which may improve performance and reduce complexity.

  In contrast to z/OS, VSE/ESA does not provide its own Java environment. For VSE/ESA shops, Linux provides the opportunity of running Java applications in close integration with existing VSE/ESA resources.

  Linux as an operating system can span a huge range of machines, from the mainframe to departmental machines to desktop PCs. Similar skills can cover deployment on different platforms. Support people speak a common language and communicate well.

• Virtualization.

  With the virtualization technology found in IBM's z/VM product, you can run tens to hundreds of Linux images on a single mainframe, thus saving on hardware cost.

• New applications.

  A broader selection of applications is available with Linux.

• Safe experimentation.

  Running evaluations or proofs of concept are easily done on a mainframe. It is quite easy to fire up a test Linux system without impacting the production workload running on the same machine (provided the spare resources are available).

• Skills are readily available.

  Since Linux is a UNIX-like operating system, a rich set of skills is available in the marketplace and from colleges and universities.