IBM Z Mainframe Supports 5 Unique Operating Systems
Part Three - Challenge #12


The contest z/OS is a virtual machine controlled by a single LPAR running z/VM

IBM Z is computer hardware, the mainframe
IBM Z supports 5 unique operating systems:
  1. z/OS - flagship operating system used for this contest
  2. Linux - if you know Linux, you know Linux that runs on IBM Z
  3. z/VM - hypervisor operating system
  4. z/TPF - Transaction Processing Facility
  5. z/VSE - similar to z/OS with less features and functions
If you want to read more about these operating systems:
IBM Z Operating Systems

IBM Z supports 2 types of hypervisors:
  1. LPAR - Logical Partition, a type 1 hypervisor
  2. z/VM - z/Virtual Machine, a type 2 hypervisor
If you want to read more about hypervisors:
Types of Hypervisors

IBM Z unparalleled server capability
  • LPAR hardware hypervisor is assigned CPU's, Memory, and Peripheral Devices such as disk, network, tape, etc, from the total available resource pool.
  • Any of the 5 operating systems can run in an LPAR.
  • A single IBM Z is capable or running up to 85 LPARs.
  • z/VM is a software hypervisor.
  • Any of the 5 operating systems can be a guest virtual machine within the z/VM environment.
  • It is common to use z/VM hypervisor to run 100's and even 1000's of Linux operating systems.
  • Communication between the operating systems in the IBM Z frame eliminates the requirement for extra cables and the response time between operating systems is near zero.
  • Running 8,000+ operating systems within a single IBM Z frame with network delay between the operating systems near zero is industrial strength architecture.

Information about the contest IBM Z mainframe

While previous years' contests exposed contestants to other IBM Z operating systems, 2018 contest is all z/OS. However, the contest z/OS is running as virtual machine under z/VM where the z/VM is running in one of several LPARs on the contest IBM Z hardwere - contest system is using a very small fraction of the IBM Z frame.

As a result of the contest z/OS running as a virtual machine under z/VM, it is possible to 'query' z/VM from z/OS.

If you want free access to Linux running on IBM Z:
Start your trial now

z/VM query command output in preparation for challenge
From ISPF/TSO =6 panel (ISPF Command Shell), enter the following z/VM Query commands:
  • q cplevel
      z/VM Operating System Level hosting the contest z/OS virtual machine
  • q n
      Number of virtual machines currently active as guests of z/VM
  • q nic
      Network Interface Controller
      Observe the NIC Adapter device number (400) and the NIC Adapter Name
        Write down the NIC Adapter Name - you will need it to complete challenge
    The NIC adapter device number is the first of three z/VM device addresses used to
    communicate with z/OS virtual machine
  • q 400-402
      z/VM defined NIC Adapter Devices 400 to 402


Gather z/OS system definitions used to communicate with z/VM hypervisor
The following information is available from the z/VM query commands:
  • z/VM NIC adapter device addresses 400-402 are used to communicate with z/OS
  • z/VM NIC adapter name is known - you were asked to write it down previously


dslist 'vendor.tcpparms'
  1. View 'v' vendor.tcpparms partitioned data set
  2. Select 's' member name S0W1
      The data is the z/OS TCPIP definitions which includes the z/OS HOME IP address and NIC adapter name
      No worries - any attempt to save changes will fail due to read-only authority
  3. Delete all lines except the 3 lines with the NIC adapter name
  4. After 'a' the third and last line, enter ISPF edit primary command
    copy 'lvl0.vtamlst(osatrl)'
      You are looking at additional z/OS definitions used to establish connection with z/VM
  5. Type ISPF line command c99 over top of the first line number and enter ISPF primary command
    rep p3.output(#12) to copy all lines to p3.output(#12)
  6. Enter ISPF edit primary command cancel to exit view session.

If done correctly, p3.output(#12) has 7 lines consisting of z/OS definitions used to connect to z/VM.

Great progress! Only 3 more challenges to be a candidate for winner or honorable mention status.

Next: Challenge #13