The terminal server environment

A terminal server environment includes a terminal server and multiple target systems.

Figure 1. Terminal server environment

This graphic shows a terminal server and multiple target systems; the components that are shown in the graphic are explained in the text that follows

To access a terminal device on a target system, administrators first open a terminal session on a workstation. They then log in to a special terminal server shell, the ts-shell, on the terminal server. The terminal shell uses the iucvconn program that can access terminal devices on target systems through z/VM® IUCV connections.

Linux on z Systems™ supports two types of terminal devices that can be accessed through z/VM IUCV.

Terminal devices that are provided by the iucvtty program.
For simplicity, these terminal devices are referred to as iucvtty instances in this document.
Terminal devices that are provided by the z/VM IUCV hypervisor console (HVC) device driver.
For simplicity, these terminal devices are referred to as HVC terminal devices in this document.

Both types of devices can be present on the same Linux instance and there can be multiple instances of each type. Each instance of a terminal device is accessed through a separate z/VM IUCV connection.