CPU management during a VM Migration

If a different number of CPUs is attached to the CPU pool of the target SU than to the CPU pool of the source SU, the multiprocessor level of the migrated VM is adjusted accordingly on the target SU. This procedure has the same effect as executing the /ASSIGN-VM-TO-CPU-POOL ATTACHED-VM-CPUS=*ADJUST-NUMBER VM2000 command. I.e. redundant virtual CPUs of the VM are detached and set to BLOCK status. Additionally available virtual CPUs (in BLOCK state) are attached if necessary. See the operand description in section "ASSIGN-VM-TO-CPU-POOL (Assign a VM to a CPU pool)".

Exception

Virtual CPUs of the VM that have been detached on the source SU by the guest system using /DETACH-DEVICE (they are not in BLOCK state), will not be attached again.

After a VM Migration, the distribution of CPU capacity (CPU quota and maximum CPU utilization) should be reconsidered and, if necessary, optimized on both the target and source SU.