HP Capacity Advisor 7.2 User Guide

Table 3 Percent of time conversions (continued)
Hours/Day
(24–hour day)
Hours/ WeekMinutes/ WeekPercent of Time
7.2050.43,024.030
24.00168.0010080.0100
Understanding utilization limit messages
Percentage of allocation
The utilization limit messages are shown as a percentage of allocation, where allocation is subset
of the given hardware for the system the workload is running on. For example, for a one-core
system, the allocation is one CPU. The CPU utilization limit of 50% would mean 50% of one core,
or .5 cores. However, this percentage changes when the hardware (allocation) changes. If two
additional cores are added (say through dynamic CPU migration with vPars), the CPU utilization
limit of 50% would mean 50% of three cores, or 1.5 cores.
Allocation values for network IO and disk IO are derived from either the highest observed value
for that metric over the entire range of data collected, or a user-specified maximum value.
The allocation values for network and disk might be updated each time utilization data is collected
from the system. If a new high observed value occurs during the time period collected, the network
or disk allocation value for the system is increased to reflect it. This increased value then affects
any network or disk utilization limits for workloads on that system. The current allocation values
for a system are displayed on the Profile Viewer page under Platform Characteristics.
With sustained limits
A sustained utilization limit could be set such that CPU utilization cannot exceed 50% of allocation
for 20 consecutive minutes, where the allocation of hardware is based upon a three-core system.
The utilization limit message would read:
CPU utilization may not exceed 50% of allocation or 1.5 cores for more
than 20 minutes.
With percentage of time limits
A percentage of time utilization limit could be set such that CPU utilization cannot exceed 50% of
allocation for more 10% of the time, where the allocation is based upon a three-core system. The
utilization limit message would read:
CPU utilization may not exceed 50% of allocation or 1.5 cores for more
than 10% of the time.
Scope of utilization limits
Utilization limits can be set to apply broadly or narrowly within the Capacity Advisor user interface:
• Globally. These limits apply to every workload, wherever workloads are analyzed.
• By Workload. These limits apply to one specific workload, wherever that workload is analyzed.
• Scenario-wide. These limits apply to every workload within one specific scenario.
• By Scenario Workload. These limits apply to one specific workload within one specific scenario.
When a workload falls within more than one scope, only the more specific one applies, as shown
in the table below.
You can disable a more specific scope where you do not want a specific scope to apply.
30 Key Capacity Advisor concepts