Suspending a VM / resuming operation

On SU /390, a VM in the RUNNING state can be suspended using /HOLD-VM. /RESUME-VM cancels a previously initiated wait state.

 Commands /HOLD-VM and /RESUME-VM are not supported any more on SU x86.

Precautions must be taken for guest systems in the MSCF network to ensure that the guest system is not regarded as failed while it is suspended.

Figure 11: Changing the VM state by means of /HOLD-VM and /RESUME-VM

There are three different wait states:

• WAIT (VMA) initiated by a /HOLD-VM from the VM administrator (operand VM-ID= *CURRENT). The VM with which the dialog was started using /BEGIN-VM-DIALOG is suspended.

• WAIT (SEL) initiated by a selective /HOLD-VM from the VM2000 administrator (operand VM-ID=2..n). The VM with the specified VM identification is suspended.

• WAIT (GLB) initiated by a global /HOLD-VM from the VM2000 administrator. (operand VM-ID=*ALL). All currently executing VMs (except the monitor VM) are suspended.

These states may also overlap. For instance, a VM can be placed in the /HOLD-VM state by the VM administrator and in the global /HOLD-VM state by the VM2000 administrator.

The VM administrator can display the wait states of his/her VM using /SHOW-VM-ATTRIBUTES. /SHOW-VM-RESOURCES displays the states of all VMs for the VM2000 administrator. If there are overlapping wait states, only the wait state with the highest priority (in the order SEL, GLB, VMA) is displayed.

The following table shows the possible changes of state to which a VM can be subjected as a result of suspension.

Command /HOLD-VM Old status	VM2000 administrator global (VM-ID=*ALL)	VM2000 administrator selective (VM-ID=2..n)	VM administrator (VM-ID=*CURRENT)
RUNNING	GLB	SEL	VMA
VMA	VMA+GLB	VMA+SEL	VMA
SEL	SEL+GLB	SEL	SEL+VMA
GLB	GLB	GLB+SEL	GLB+VMA
VMA+SEL	VMA+SEL+GLB	VMA+SEL	VMA+SEL
VMA+GLB	VMA+GLB	VMA+GLB+SEL	VMA+GLB
SEL+GLB	SEL+GLB	SEL+GLB	SEL+GLB+VMA
VMA+SEL+GLB	VMA+SEL+GLB	VMA+SEL+GLB	VMA+SEL+GLB

Meaning:

RUNNING	VM is running
GLB	Global suspension by the VM2000 administrator (VM-ID=*ALL)
SEL	Selective suspension by the VM2000 administrator (VM-ID=2..n)
VMA	Suspension by the VM administrator (VM-ID=*CURRENT)

Changing states using the RESUME-VM command

The following rules must be observed when canceling a wait state using /RESUME-VM:

• A selective /RESUME-VM command from the VM2000 administrator (operand VM-ID=2..n) always imposes the RUNNING state. This cancels all VM wait states.

• A global /RESUME-VM command from the VM2000 administrator (operand VM-ID=*ALL) cancels a global /HOLD-VM command.

• /RESUME-VM from the VM administrator (operand VM-ID=*CURRENT) cancels a /HOLD-VM from the VM administrator.

The following table shows the possible changes of state to which a VM can be subjected by means of /RESUME-VM:

Command /RESUME-VM Old status	VM2000 administrator global (VM-ID=*ALL)	VM2000 administrator selective (VM-ID=2..n)	VM administrator (VM-ID=*CURRENT)
RUNNING	RUNNING	RUNNING	RUNNING
VMA	VMA	RUNNING	RUNNING
SEL	SEL	RUNNING	SEL
GLB	RUNNING	RUNNING	GLB
VMA+SEL	VMA+SEL	RUNNING	SEL
VMA+GLB	VMA	RUNNING	GLB
SEL+GLB	SEL	RUNNING	SEL+GLB
VMA+SEL+GLB	VMA+SEL	RUNNING	SEL+GLB

Example

VM2000-Administrator	VM-Administrator of VM2	VM2 status
	/BEGIN-VM-DIALOG VM-ID=2
	/START-VM VM-ID=2	RUNNING
	/HOLD-VM VM-ID=*CURRENT	VMA
/HOLD-VM VM-ID=*ALL		VMA+GLB
	/RESUME-VM VM-ID=*CURRENT	GLB
/RESUME-VM VM-ID=2		RUNNING
/HOLD-VM VM-ID=*ALL		GLB
/RESUME-VM VM-ID=*ALL		RUNNING