Don’t Be Afraid of the Mainframe

The DBAOTM posts have now culminated into a book.

The book is the no-bullshit introduction to the mainframe.

The 1.0 version is now for sale. For just 4 euros. Order here.

The intended audience is anyone with a need and the willingness to understand a little bit more about the mainframe in their organization – or in someone else’s organization. I have envisioned a few persona’s while writing this book: a (senior) IT manager who manages a department running mainframes; an enterprise architect, business architect or solution architect with the need to get a quick understanding of mainframe technology; a procurement person who needs to purchase mainframe hardware, software or services; a technical professional wishing to quickly explore mainframe technology.

This book will nowhere go deeply into technology, although I can’t promise some might still perceive this differently.

I called it Don’t Be Afraid Of The Mainframe because that is what I am aiming to achieve. Mainframers are usually very good at scaring non-mainframers with weird technical jargon. Or, to say it more friendly, not very good at explaining mainframe things in layman’s terms. It is my believe that the mainframe is just as simple (or complex) as any other computing tool, and maybe it is even simpler.

Feedback – and help – is very very welcome, please send me a message through the About page.

(I am sorry that’s impersonal, but my email was flooded with crap when I first published my email address).

• DBAOTM – The mainframe box, a big box
  In this post and subsequent ones, I will discuss the main hardware concepts of mainframe environments. I will not go into the tiniest detail, but I must be a bit technical. To make things easier to understand, I will compare the mainframe technology with mainstream x86 and Unix technology. You will see there is often ...
• DBAOTM – Hardware – Peripherals and other quirks
  In the previous post I introduced the mainframe server hardware. In this post I will highlight the most common peripherals – other hardware like disk storage, tape and printers. This post appears as part of a number of articles in the category “Don’t Be Afraid Of The Mainframe. Mainframe peripherals There are no hard disks in a ...
• DBAOTM – Big hardware, but partitioned in smaller parts
  In the previous post I highlighted the most common peripherals. In this post I will describe how such a big piece of equipment is chopped up in smaller logical parts. This post appears as part of a number of articles in the category “Don’t Be Afraid Of The Mainframe. Logical partitions We have seen above the mainframe machine ...
• DBAOTM – Hardware – Specialty engines
  A mainframe has a large number of CPUs. The CPUs can be configured in different modes, called specialty engines. In this post I will discuss what these specialty engines are, and how they are used. This post appears as part of a number of articles in the category “Don’t Be Afraid Of The Mainframe”. General purpose CPUs versus ...
• DBAOTM Operating systems for the big mainframe box
  In the previous posts I have given an overview of the most important mainframe hardware components. In this article I will summarize what operating systems you can run on this hardware. But first… This post appears as part of a number of articles in the category “Don’t Be Afraid Of The Mainframe”. What is actually a mainframe A ...
• DBAOTM – z/OS – the mainframe flagship operating system
  In the previous DBAOTM post I have described the operating systems available for the IBM mainframe and seen z/OS is the flagship in this category. In this post I will introduce you into the z/OS operating system concepts and terminology. The goal of this piece is to give you a good idea what is special ...
• The Unix parts of z/OS
  In the previous DBAOTM post I have introduced you to the z/OS operating system, the flagship operating system for the mainframe. In this post I will introduce you into the Unix side that z/OS has been equipped with over the past two decades. Since the 1990s IBM has added Unix functionality to z/OS. The first extension ...
• Parallel sysplex
  One of the most distinguishing features of the z/OS operating system is the way you can cluster z/OS systems in a Parallel Sysplex. Parallel Sysplex, or Sysplex in short, is a feature of z/OS that was built in the 90s that enables extreme scalability and availability. In the previous post we highlighted the z/OS Unix part. ...
• The interface to z/OS and the green screen myth
  In the previous posts I have shown you many modern technologies available on z/OS. But still when you think of the mainframe, you think of black screen with green characters, which looks cool in the Matrix, but not so much in real life. Where does this green screen imago come from? In this section I will ...
• Modern tools for development and operations
  In the previous section I explained that green screen interfaces still exist for administrative tasks. But even for these kinds of work there are modern tools with contemporary interfaces. z/OS itself and almost all middleware running on z/OS can be managed with web-based tools, Eclipse-based tools for z/OS, or nowadays more and more Visual Studio ...
• Middleware for z/OS – Application Servers
  There is a large variety of middleware tools available on z/OS. Some are very similar to the software also available on other platforms, like WebSphere Application Server and Db2, and some are only available on the mainframe, like IMS and IDMS. I will highlight a number of the main middleware tools for z/OS in this ...
• Middleware for z/OS – Database management systems
  In the previous post I started the first part of describing the middleware tools available on z/OS, kicking off with the available application servers of transaction managers. In this part I will discuss the database management systems that can run on z/OS. Db2 Db2 for z/OS is the z/OS version of IBM’s well-known relational database management system. It ...
• Programming languages for z/OS
  In this post I will discuss the programming languages you find on z/OS, and what they are generally used for. COBOL The COBOL programming language was invented 60 years ago to make programs portable across different computers. The language is best usable for business programs (as opposed to scientific programs). COBOL is a language that must be compiled ...
• Integrating z/OS applications with the rest of the world
  Many mainframe applications were built in an era where little integration with other applications was needed. Where integrations were needed, this was mostly done through the exchange of files. For example, for the exchange of information between organizations. In the 1990s the dominance of the mainframe applications ended and client-server applications emerged. These new applications required ...
• DevOps processes and tools for z/OS
  In this post I will discuss a traditional view of the DevOps processes and tools for z/OS, and in the follow-on post I will discuss a somewhat futuristic view. The ideal situation for development for z/OS is work for all of us. However, significant progress has been made of the past few years to change ...
• Modern mainframe application development
  In the previous DBAOTM article on DevOps I have introduced the traditional development process, which is often still used in a mainframe environment. In this post I will present a modern approach to development on the mainframe. Modern development processes for the mainframe Requirements for the development process have changed. Applications must be built faster and it ...
• Security on z/OS
  Security has always been one of the strong propositions and differentiators of the mainframe and the z/OS operating system. In this post I will highlight a few of the differentiating factors of the mainframe hardware and the z/OS operating system. The mainframe provides a number of distinguishing security features in its hardware. In z/OS a centralized ...
• System management
  The z/OS operating system is designed to host many applications on a single platform. From the beginning, efficient management of the applications and their underlying infrastructure has been an essential part of the z/OS ecosystem. This chapter will discuss the regular system operations, monitoring processes, and tools you find on z/OS. I will also look at ...