Detaching and attaching the components CPU, CHN, CTL and DVC

Detachment of components by the operating system

Components that fail are automatically detached. The operator then receives the following message at the main console:

NKR0048	'CHANNEL=mn' DETACHED BY SYSTEM **********	(for CHN)
ETMRK48	CPUxy DETACHED BY SYSTEM **********	(for CPU)

mn	Mnemonic device name of the component

Message ETMRK48 must be acknowledged by the operator. This prevents components from being detached without the operator's knowledge.

The message is output to the main console connected to the unaffected I/O processor.

Attachment or reattachment is performed by the operator using the ATTACH-DEVICE command, although this is not always possible.

Detachment of components by the operator

The operator can detach components by means of the DETACH-DEVICE command (see the “Commands” manual [27]).

The operating system confirms that each component has been successfully detached by the following message to the console:

NKR0045	'CHANNEL=mn' DETACHED **********	(for CHN)
ETMRK19	CPUxy DETACHED **********	(for CPU)

The DETACH-DEVICE command is rejected with an appropriate message if it cannot be performed at the present time.
For channels and device controllers under VM2000 on SUs /390, detachment can only be performed in the monitor system in the local system or in all BS2000 guest systems (globally in VM2000). The command must then be entered on the monitor system.

Attachment/reattachment is performed by means of the ATTACH-DEVICE command.

Attachment of components by the operator

The operator can attach components by means of the ATTACH-DEVICE command in the following cases:

• if a component becomes available again following a failure or servicing

• if system initialization was performed without a component.

For channels and device controllers under VM2000 attachment can only be performed in the monitor system in the local system or in all BS2000 guest systems (globally in VM2000).

The operating system confirms that each component has been properly attached by means of the following message to the console:

NKR0040	'<unit-class>=mn' ATTACHED	(for CHN, CTL, DVC)
ETMRK18	CPUxy ATTACHED	(for CPU)

Attaching and detaching extra CPUs

Extra CPUs can exist on every Server Unit.

The operator can attach one or more extra CPUs while the system is running with the ATTACH-DEVICE UNIT=*EXTRA-CPU(CPU-ID=...) command.

The extra CPUs are detached with the DETACH-DEVICE command.

See "Attaching and detaching extra CPUs" in section "Functionality in BS2000 native operation" for more detailed information on attaching and detaching extra CPUs.