Accessing terminal devices over z/VM IUCV

Ubuntu 22.04 LTS z/VM guest

Use z/VM IUCV to access hypervisor console (HVC) terminal devices, which are provided by the z/VM IUCV HVC device driver.

About this task

For information about accessing terminal devices that are provided by the iucvtty program see How to Set up a Terminal Server Environment on z/VM, SC34-2596.

You access HVC terminal devices from a Linux® instance where the iucvconn program is installed. The Linux instance with the terminal device to be accessed and the Linux instance with the iucvconn program must both run as guests of the same z/VM system. The two guest virtual machines must be configured such that IUCV communication is permitted between them.

Procedure

Perform these steps to access an HVC terminal device over z/VM IUCV:

  1. Open a terminal session on the Linux instance where the iucvconn program is installed.
  2. Enter a command of this form: 
    # iucvconn <guest_ID> <terminal_ID>
    where:
    <guest_ID>
    specifies the z/VM guest virtual machine on which the Linux instance with the HVC terminal device to be accessed runs.
    <terminal_ID>
    specifies an identifier for the terminal device to be accessed. HVC terminal device names are of the form hvcn where n is an integer in the range 0-7. The corresponding terminal IDs are lnxhvcn.
    Example: To access HVC terminal device hvc0 on a Linux instance that runs on a z/VM guest virtual machine LXGUEST1, enter: 
    # iucvconn LXGUEST1 lnxhvc0

    For more details and further parameters of the iucvconn command, see the iucvconn man page or How to Set up a Terminal Server Environment on z/VM, SC34-2596.

  3. Press Enter to obtain a prompt.

    Output that is written by Linux while the terminal window is closed, is not displayed. Therefore, a newly opened terminal window is always blank. For most applications, like login or shell prompts, it is sufficient to press Enter to obtain a new prompt.

Security hint

Always end terminal sessions by explicitly logging off (for example, type exit and press Enter). If logging off results in a new login prompt, press Control and Underscore (Ctrl+_), then press D to close the login window. Simply closing the terminal window for a hvc0 terminal device that was activated for Linux kernel messages leaves the device active. The terminal session can then be reopened without a login.