Note
	Whenever you see “CD-ROM” in this manual, it applies to all of CD-ROMs, DVD-ROMs and BD-ROMs, because all these technologies are really the same from the operating system's point of view. On IBM S/390 the CD-ROM / DVD-ROM drive of the Hardware Management Console (HMC) can be used for LPAR installations.

CD-ROM based installation is supported for most architectures.

The network can be used during the installation to retrieve files needed for the installation. Whether the network is used or not depends on the installation method you choose and your answers to certain questions that will be asked during the installation. The installation system supports HTTP and FTP network connections. After the installation is completed, you may configure additional network connections.

Please notice that the "Load from Removable Media" task of the Hardware Management Console (HMC) also supports installations from a CD-/DVD-ROM or even a USB media that is plugged into the HMC. Since these media are not local to the S/390 system (LPAR, virtual machine) that you are going to install, it is a different approach compared to a distributed system and special to the S/390 platform.

Booting the installation system directly from a hard disk is another option for many architectures. This will require some other operating system to load the installer onto the hard disk. This method is only recommended for special cases when no other installation method is available.

If you are running another Unix-like system, you could use it to install Ubuntu without using the debian-installer described in the rest of this manual. This kind of install may be useful for users with otherwise unsupported hardware or on hosts which can't afford downtime. If you are interested in this technique, skip to the Section D.4, “Installing Ubuntu from a Unix/Linux System”. This installation method is only recommended for advanced users when no other installation method is available.

The Ubuntu installer contains a kernel which is built to maximize the number of systems it runs on.

Any storage system supported by the Linux kernel is also supported by the boot system. This means that FBA and ECKD DASDs are supported with the old Linux disk layout (ldl) and the new common S/390 disk layout (cdl, recommended), as well as FCP (SCSI over Fibre Channel).