A reconfiguration command has no effect if a state is to be selected which has already been set or which cannot be set. The relevant messages are output.
Under VM2000, it is possible to attach or detach channels, controllers and connections in the monitor system only in the local system or in all BS2000 guest systems (globally in VM2000).
The operand SCOPE=OWN-SYSTEM-ONLY/VM2000-GLOBAL has been introduced for this purpose.
ATTACH-DEVICE
If a valid ATTACH-DEVICE command is entered, this has the following effect:
If the specified hardware units were in the DETACHED EXPLICITLY state they enter the ATTACHED state. The hardware units can be used once again.
If the outer connections associated with these hardware units were in the REMOVED IMPLICITLY state, they enter the INCLUDED state. The virtual connections can be used once again.
The outer hardware units which are connected to these units and which were in the DETACHED IMPLICITLY state enter the ATTACHED state if at least one virtual connection to the outer unit is in the state INCLUDED.
DETACH-DEVICE
A valid DETACH-DEVICE command has the following effect:
Each of the hardware units specified assumes the DETACHED EXPLICITLY state. They cannot be used.
All outer connections associated with these hardware units enter the REMOVED IMPLICITLY state. They cannot be used.
All outer hardware units connected to these units assume the DETACHED IMPLICITLY state if the connection to the directly detached unit was the last or the only virtual connection. These external hardware units cannot be used.
Detachment with the parameter SCOPE=*VM2000-GLOBAL is successful only if it was possible to implement detachment successfully in all BS2000 guest systems.
The forced detachment of channels is enabled in the monitor system by the operand FORCE=*UNCONDITIONAL-OFFLINE under VM2000 (SUs /390).
INCLUDE-DEVICE-CONNECTION
The entry of a valid INCLUDE-DEVICE-CONNECTION command has the following effect:
If the virtual connections specified were in the REMOVED EXPLICITLY state, they enter the INCLUDED state. The connections can be used once again.
If the outer units associated with the connections were in the DETACHED IMPLICITLY state, they enter the ATTACHED state. These hardware units can be used once again.
The outer connections extending from these hardware units enter the INCLUDED state if they were previously in the REMOVED IMPLICITLY state. These outer connections can be used again.
REMOVE-DEVICE-CONNECTION
Valid input of the REMOVE-DEVICE-CONNECTION command has the following effect:
The virtual connections specified enter the REMOVED EXPLICITLY state. They can no longer be used.
The outer hardware units attached to these connections enter the DETACHED IMPLICITLY state if the detached connection was the last or only inner connection. These hardware units can no longer be used.
The outer connections extending from these outer hardware units in the DETACHED IMPLICITLY state enter the REMOVED IMPLICITLY state. They can no longer be used.
Interfaces for KVP consoles
The two I/O interfaces (device type SKP2) constitute a single virtual unit for the operating system. With ATTACH/DETACH tasks it ensures that both interfaces assume the same state. A precondition is that both paths from the controller to the interfaces should also be in the same state. If the paths are put in different states using INCLUDE-/REMOVE-DEVICE-CONNECTION, correct error handling of the interfaces by the system is not longer guaranteed.
Activating hardware units and connections is the responsibility of the operator. Hardware units and connections are deactivated either by the operator or (in serious cases) by the system.
The operator is responsible for coordination when hardware units which are connected to several systems are attached or detached.
Devices in the DETACH-PENDING state can be used by the volume monitoring in the event of remount jobs if no other free devices are available.
FastDPAV alias devices
After successful execution of the ATTACH-DEVICE command for a FastDPAV alias device, the device enters the ENABLED state. This means that the FastDPAV alias device can be used for input/output.
After successful execution of the DETACH-DEVICE command for a FastDPAV alias device, the device enters the DISABLED state. This means that the FastDPAV alias device cannot be used for input/output.