Chapter 15. Planning for Installation on IBM System z

15.1. Pre-installation

Red Hat Enterprise Linux 7 runs on zEnterprise 196 or later IBM mainframe systems.
The installation process assumes that you are familiar with the IBM System z and can set up logical partitions (LPARs) and z/VM guest virtual machines. For additional information on System z, see
For installation of Red Hat Enterprise Linux on System z, Red Hat supports DASD (Direct Access Storage Device) and FCP (Fiber Channel Protocol) storage devices.
Before you install Red Hat Enterprise Linux, you must decide on the following:
  • Decide whether you want to run the operating system on an LPAR or as a z/VM guest operating system.
  • Decide if you need swap space and if so, how much. Although it is possible (and 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. See Section, “Recommended Partitioning Scheme”.
  • Decide on a network configuration. Red Hat Enterprise Linux 7 for IBM System z supports the following network devices:
    • Real and virtual Open Systems Adapter (OSA)
    • Real and virtual HiperSockets
    • LAN channel station (LCS) for real OSA
You require the following hardware:
  • Disk space. Calculate how much disk space you need and allocate sufficient disk space on DASDs[2] or SCSI[3] disks. You require at least 10 GB for a server installation, and 20 GB if you want to install all packages. You also require disk space 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.
    For more information about disks and partition configuration, see Section, “Recommended Partitioning Scheme”.
  • RAM. Acquire 1 GB (recommended) for the Linux instance. With some tuning, an instance might run with as little as 512 MB RAM.


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

[2] Direct Access 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.
[3] Using the SCSI-over-Fibre Channel device driver (the zfcp device driver) and a switch, SCSI LUNs can be presented to Linux on System z as if they were locally attached SCSI drives.