Chapter 35. Planning for installation on 64-bit IBM Z

Red Hat Enterprise Linux 9 runs on z13 or later IBM mainframe systems.

The installation process assumes that you are familiar with the 64-bit IBM Z and can set up logical partitions (LPARs) and z/VM guest virtual machines.

For installation of Red Hat Enterprise Linux on 64-bit IBM Z, Red Hat supports Direct Access Storage Device (DASD) and Fiber Channel Protocol (FCP) storage devices.


DASDs are hard disks that allow a maximum of three partitions per device. For example, dasda can have partitions dasda1, dasda2, and dasda3.

Pre-installation decisions

  • Whether the operating system is to be run on an LPAR or as a z/VM guest operating system.
  • If swap space is needed, and how much. Although it is recommended to assign enough memory to a z/VM guest virtual machine and let z/VM do the necessary swapping, there are cases where the amount of required RAM is hard to predict. Such instances should be examined on a case-by-case basis.
  • Network configuration. Red Hat Enterprise Linux 9 for 64-bit IBM Z supports the following network devices:

    • Real and virtual Open Systems Adapter (OSA)
    • Real and virtual HiperSockets
    • LAN channel station (LCS) for real OSA

Disk space

You will need to calculate and allocate sufficient disk space on DASDs or SCSI disks.

  • A minimum of 10 GB is needed for a server installation, 20 GB if you want to install all packages.
  • Disk space is also required for any application data. After the installation, you can add or delete more DASD or SCSI disk partitions.
  • The disk space used by the newly installed Red Hat Enterprise Linux system (the Linux instance) must be separate from the disk space used by other operating systems you have installed on your system.


Ensure that your system has sufficient RAM available:

  • Minimum 1.5 GB when installing from NFS.
  • Minimum 3 GB when installing from an HTTP or FTP installation source.
  • When installing in text mode, 1GB is sufficient only if you are using an NFS installation source.
  • Red Hat recommends 2 GB for the installed Linux instance. However, 1GB is sufficient on a properly tuned system.

When initializing swap space on a Fixed Block Architecture (FBA) DASD using the SWAPGEN utility, the FBAPART option must be used.

Additional resources