In order to install Ubuntu on an IBM Z or LinuxONE machine you have first boot a kernel into the system. The boot mechanism of this platform is inherently different to other ones, especially from PC-like systems: there are no floppy devices available at all. You will notice another big difference while you work with this platform: most (if not all) of the time you will work remote, with the help of some client session software like 3270, ssh, or a browser. This is due to that special system architecture where the 3215/3270 console is line-based instead of character-based.

Linux on this platform runs either natively in a so-called LPARs (Logical Partitions) or in a virtual machine supplied by the z/VM or KVM hypervisor. Boot media differs depending on the runtime mode. For example, you can use the virtual card reader of a z/VM virtual machine, or boot from the HMC (Hardware Management Console) of an LPAR if the HMC and this option (Load from Removable Media) is available for you, or boot from the kernel and initrd provided by the ISO image or directly from the ISO image in case of KVM.

Before you actually perform an installation, you have to go over some design and preparation steps. IBM has made documentation available about the whole process, e.g. how to prepare an installation medium and how actually to boot from that medium. Duplicating that information here is neither possible nor necessary. However, we will describe here which kind of Ubuntu-specific data is needed and where to find it. Using both sources of information, you have to prepare your machine and the installation medium before you can perform a boot from it. When you see the welcome message in your client session, return to this document to go through the Ubuntu-specific installation steps.

Please refer to chapter 5 of the Linux for S/390 Redbook and chapter 3.2 of the Linux for IBM eServer zSeries and S/390: Distributions Redbook on how to set up an LPAR for Linux.

Please refer to chapter 6 of the Linux for S/390 Redbook and chapter 3.1 of the Linux for IBM eServer zSeries and S/390: Distributions Redbook on how to set up a VM guest for running Linux.

It's recommended to copy all the files from the boot sub-directory of your ISO image to your CMS disk - “usually your File Mode” (Fm) “A” or a dedicated one for installation files. But be sure to transfer at least the following files: kernel.ubuntu and initrd.ubuntu in binary mode with a fixed record length of 80 characters (by specifying BINARY and LOCSITE FIX 80 in your FTP client). parmfile.debian and ubuntu.exec can be in either ASCII or EBCDIC format. The ASCII file ubuntu.exec is a sample REXX script, that will “punch” the files in the proper order.

If you don't have a connection to the Internet (either directly or via a web proxy) you usually need to create a local installation server that can be accessed from your s390x system. This server keeps all the packages you want to install and must make them available using HTTP or FTP (recommended).

The installation server needs to copy the exact directory structure from any Ubuntu mirror, but only the s390x and the architecture-independent files are required. You can also copy the contents of all installation ISO image into such a directory tree.

	Note
	Make sure to also include and copy the “hidden” files and folders of the ISO image, like the folder .disk