Service Ratio - Hitachi Compute Blade 500 Series User Manual

Service Ratio

To the LPARs in the Shared Processor Mode, you can set the relative
processor resource allocation rate (called 'Service Ratio'), which represents
the ratio of the time period in which the LPAR actually run on the physical
processors (called 'Service Time'). The Service Ratio can be specified from 1
to 999.
LPAR manager partitions the performance of the physical processor used in
shared mode in 1 percent unit. LPAR manager calculates the relative
allocation rate of the service time with 10-millisecond time-slice accuracy,
which equals 1% of a unit processor time (1 second).
Service ratio has a meaning only to LPAR of shared mode. Service ratio does
not have any meaning to LPAR of shared mode, and cannot be assigned.
The examples of the relations between Service Ratio and allocation rate are
as follows.
(Example 1)
This example shows the allocation rates of LPAR1 (Service Ratio=100, the
number of the logical processors=2) and LPAR2 (Service Ratio=100, the
number of the logical processors=2) when the number of the physical
processor can be used by the shared mode LPARs is 3.
(Example 2)
This example shows the allocation rates of LPAR1 (Service Ratio=100, the
number of the logical processors=2), LPAR2 (Service Ratio=100, the number
of the logical processors=2) and LPAR3 (Service Ratio=100, the number of
the logical processors=3), when the number of the physical processor can be
used by the shared mode LPARs is 3, and LPAR3 is added while LPAR1 and
LPAR2 are running.
1-6
Hitachi Compute Blade 500 Series Logical partitioning manager User's Guide
Figure 1-6 Service Ratio Example 1
LPAR manager Functions