Before a VM group can be worked with, it must be created in VM2000. A VM group is created by the VM2000 administrator using /CREATE-VM-GROUP.
When a VM group is created it is assigned the following attributes:
Name of the VM group
CPU quota and maximum CPU utilization of the VM group
CPU pool of the VM group
Up to half as many VM groups as VMs may be created (rounded up). The number of VMs depends on the architecture of the Server Unit, see "Comparison of VM2000 on SU /390 and SU x86".
Example
A maximum of 15 VMs are permitted on an SU /390. A maximum of 8 VM groups can thus be created.
The maximum number of VMs and the maximum number of VM groups are also displayed using /SHOW-VM-RESOURCES INFORMATION=*CONFIGURATION.
Name of the VM group
The name of a VM group can be freely selected. It must identify the VM group unambiguously. /CREATE-VM-GROUP is rejected if a specified VM group name has already been assigned.
Recommendations for defining and using the names of VM groups
The name of a VM group should be unique within a VM2000 installation (data center organization) and indicate the purpose of the VM group.
The name ranges for VMs, VM groups and CPU pools should be disjunctive.
CPU quota and maximum CPU utilization of the VM group
The CPU quota of the VM group determines the share of the VM group in the CPU capacity of the assigned CPU pool in comparison to the other VMs which are assigned to the same CPU pool either directly or as members of a VM group.
The CPU utilization of a VM group can be restricted by the maximum CPU utilization. This value also implicitly restricts the CPU utilization of every VM which belongs to the VM group.
The CPU quota and maximum CPU utilization of the VM group can be modified later using /MODIFY-VM-GROUP-ATTRIBUTES.
CPU pool, to which the VM group is assigned
Each VM group is always assigned to precisely one CPU pool. By default (CPU-POOL-NAME=*STDPOOL operand) the VM group is assigned to the standard CPU pool at initialization time.
The assignment of a VM group to a CPU pool can be changed later using /ASSIGN-VM-GROUP-TO-CPU-POOL.