Chapter 33. Planning for installation on 64-bit IBM Z

Red Hat Enterprise Linux 8 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), Fiber Channel Protocol (FCP) storage devices, and virtio-blk and virtio-scsi devices. When using FCP devices, Red Hat recommends using them in multipath configuration for better reliability.

Important

DASDs are 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, KVM, 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 8 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
    • virtio-net devices

Disk space

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

  • A minimum of 10 GiB is needed for a server installation, 20 GiB 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.

RAM

Ensure that your system has sufficient RAM available:

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

Additional resources