IBM Power 720 Express, Обзор

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Chapter 3. Virtualization
131
If the Power Systems server is under heavy load, each micropartition within a shared
processor pool is guaranteed its processor entitlement plus any capacity that it might be
allocated from the reserved pool capacity if the micropartition is uncapped.
If certain micropartitions in a shared processor pool do not use their capacity entitlement, the
unused capacity is ceded and other uncapped micropartitions within the same shared
processor pool are allocated the additional capacity according to their uncapped weighting. In
this way, the entitled pool capacity of a shared processor pool is distributed to the set of
micropartitions within that shared processor pool.
All Power Systems servers that support the multiple shared processor pools capability will
have a minimum of one (the default) shared processor pool and up to a maximum of 64
shared processor pools.
Default shared processor pool (SPP
0
)
On any Power Systems server supporting multiple shared processor pools, a default shared
processor pool is always automatically defined. The default shared processor pool has a pool
identifier of zero (SPP ID = 0) and can also be referred to as SPP
0
. The default shared
processor pool has the same attributes as a user-defined shared processor pool except that
these attributes are not directly under the control of the system administrator. They have fixed
values (Table 3-4).
Table 3-4 Attribute values for the default shared processor pool (SPP
0
)
Creating multiple shared processor pools
The default shared processor pool (SPP
0
) is automatically activated by the system and is
always present. All other shared processor pools exist, but by default are inactive. By
changing the maximum pool capacity of a shared processor pool to a value greater than zero,
it becomes active and can accept micropartitions (either transferred from SPP
0
or newly
created).
Levels of processor capacity resolution
The following two levels of processor capacity resolution are implemented by the POWER
Hypervisor and multiple shared processor pools:
򐂰 Level
0
This first level is the resolution of capacity within the same shared processor pool. Unused
processor cycles from within a shared processor pool are harvested and then redistributed
to any eligible micropartition within the same shared processor pool.
򐂰 Level
1
This second level of processor capacity is after all first level capacity is resolved. When all
Level
0
capacity has been resolved within the multiple shared processor pools, the
POWER Hypervisor harvests unused processor cycles and redistributes them to eligible
micropartitions regardless of the Multiple shared processor pools structure.
SPP
0
attribute Value
Shared processor pool ID 0
Maximum pool capacity The value is equal to the capacity in the physical shared
processor pool.
Reserved pool capacity 0
Entitled pool capacity Sum (total) of the entitled capacities of the micropartitions in the
default shared processor pool.