In this chapter, we discuss considerations when setting up Linux on the mainframe. These considerations cover obtaining a distribution, installing it, and customizing it. The customization section discusses options for creating Linux images for different purposes in an efficient way using z/VM. Customization also covers I/O considerations when setting up the environment.
In general, installing the Linux operating system on the mainframe is no different from other platforms. Setting up the hardware for Linux on the mainframe is different because of virtualization technology. Setting up virtual hardware can be easier (and potentially less costly) than setting up real hardware.
Installing Linux itself on the mainframe is relatively easy, as was demonstrated by the "Install Fests" (see 3.2.2, "Spreading the word the Linux install fest"). The initial installation is described in the respective distributor's documentation and is not repeated here. Instead, we focus on configuration choices that can give you some value from Linux on the mainframe.
With Linux on the mainframe, you have an interesting opportunity during the configuration process to address the key areas of availability, security, and management. You can set up for availability early when creating your images. You can also set up for security to a certain degree, and Linux on the mainframe can make it easier to manage both software change and operations. For example, operation management can be simplified if z/VM is set up to be the health monitor. These are choices that you can make when configuring z/VM and the Linux guests.
In this chapter we explore these questions: