IBM Power 720 - Page 146

132 IBM Power 720 and 740 Technical Overview and Introduction
Figure 3-9 shows the levels of unused capacity redistribution implemented by the POWER
Hypervisor.
Figure 3-9 The levels of unused capacity redistribution
Capacity allocation above the entitled pool capacity (Level
1
)
The POWER Hypervisor initially manages the entitled pool capacity at the shared processor
pool level. This is where unused processor capacity within a shared processor pool is
harvested and then redistributed to uncapped micropartitions within the same shared
processor pool. This level of processor capacity management is sometimes referred to as
Level
0
capacity resolution.
At a higher level, the POWER Hypervisor harvests unused processor capacity from the
multiple shared processor pools that do not consume all of their entitled pool capacity. If a
particular shared processor pool is heavily loaded and several of the uncapped
micropartitions within it require additional processor capacity (above the entitled pool
capacity), then the POWER Hypervisor redistributes some of the extra capacity to the
uncapped micropartitions. This level of processor capacity management is sometimes
referred to as Level
1
capacity resolution.
POWER Hypervisor
SPP
n
SPP
2
SPP
1
SPP
0
Micro-partition
n
SPP
2
capacity
resolution
SPP
n
capacity
resolution
SPP
1
capacity
resolution
SPP
0
capacity
resolution
Physical Shared Processor Pool
p0 p1 p2 p3 p4 p5
Level
1
capacity
resolution
Level
1
capacity resolution
POWER Hypervisor harvests unused
processor capacity from Shared-Processor
Pools and redistributes it across all
uncapped micro-partitions regardless of the
Shared-Processor Pool structure
Level
0
capacity resolution
Resolution of the Entitled Pool Capacity
within the same Shared-Processor Pool
Level
0
capacity
resolution
Micro-partition
0
Micro-partition
1
Micro-partition
2
Micro-partition
3
Micro-partition
n