Special applications (VM2000)

Notes on SM2 operation

Note

The corresponding values can also be output by using the VM2000 command SHOW- VM-STATUS (see the “VM2000” manual [9]).

VM2000 operation on /390 architecture

The overall CPU utilization is determined by taking the HYPERVISOR-IDLE value and extrapolating the difference to 100%.

The IDLE value given by the SM2 monitoring program loses its original meaning, in which case it merely acts as an indicator of the percentage for a given time period, one during which the respective guest system was inactive of its own volition.

Example:

2 guest systems, VM1 and VM2

 

Each guest system is to be active for 50 s within the time period of 100 s.

Ideal situation: No idling occurs

VM1

VM2

SM2-Idle=50 %

Hypervisor-Idle=0 %

SM2-Idle=50 %

– Realistic case: idling does occur for half of the required active period (***)

VM1

VM2

*****

*****

SM2-Idle=33 %

Hypervisor-Idle=0 %

SM2-Idle=33 %

The SM2 idle value of 33% is explained by the fact that SM2 precisely monitors the active time (50 s), adds the voluntary inactive time (reduced to 25 s as the result of idling), and relativizes it to 100%.

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Siemens SM2 monitoring system, U3585-J-Z125-8-76 1 manual VM2000 operation on /390 architecture