Devices that are connected to the system can be in one of four states.

Devices that are connected to the system can be in one of the following states:

Item

Description

Undefined

The device is unknown to the system.

Defined

Specific information about the device is recorded in the customized database, but it is unavailable to the system.

Available

A defined device is coupled to the operating system, or the defined device is configured.

Stopped

The device is unavailable but remains known by its device driver.

If a tty device and a printer alternately use the same tty connector, both a tty device and a printer are defined on the same parent and port in the device configuration database. Only one of these devices can be configured at a time. When the tty connector is configured, the printer specific setup information is retained until it is configured again. The device is not removed; it is in the defined state. Maintaining a device in defined state retains customized information for a device that is not currently in use, either before it is first made available or while it is temporarily removed from the system.

If a device driver exists for a device, the device can be made available through the device driver.

https://www.ibm.com/docs/en/aix/7.2?topic=nodes-device-states