HP Matrix Operating Environment Software - Manual (Page 28)

(For more information on how utilization is calculated for each resource, see Appendix C (page 149)
.)
Specifying utilization limits
There are three building blocks to specifying a utilization limit:
•
The limit The maximum percentage or absolute amount of a resource allowed to be used
by a workload. For example, a CPU utilization limit might be “not above 90%” utilization.
• The resource Utilization limits are applied to specific resources:
— CPU cores
— memory
— network I/O bandwidth
— disk I/O bandwidth
TIP:
You can specify more than one utilization limit for a resource Using the Utilization Limits
Editor, you can add multiple settings for a resource. For example, you can create multiple
different utilization limits for CPU cores by varying percentage and allowed duration for
each limit. Multiple limits for CPU cores could look like this:
— Utilization can exceed 90 percent of assigned cores 0 percent of the time
— Utilization can exceed 85 percent of assigned cores for a maximum of 5 minutes duration
Not specifying a limit allows HP Smart Solver to over-provision systems To achieve best
results with the Smart Solver, it is better to set specific limits, rather than to depend on the
default settings for limits to provide the best fit.
• The time criteria You can specify the time portion of a utilization limit in either of two
ways:
— Sustained (consecutive) time limits
— Percentage of time limits
Sustained time limits
A sustained limit specifies a limit where the resource cannot exceed that utilization limit for X
consecutive minutes. For example, if X is 20, this means that the resource cannot exceed the
utilization limit for 20 consecutive minutes.
Because the Capacity Advisor collects data samples every 5 minutes, the time X for the sustained
limit must be a multiple of 5 minutes; the minimum for X is 0 minutes.
Percentage of time limits
A percentage of time limit specifies that the resource cannot exceed the limit for more than the
designated percent of time, where percent of time is related to the percentile utilization ranges
in the Capacity Advisor data.
Given that there are about 10,000 minutes in a week, 3% of the time is roughly 300 minutes (3%
of 10,000). These 300 minutes total to 5 hours per week. Below is a table relating percentages of
time to hours per week, which may help you in specifying percent of time utilization limits.
Table 3-1 Percent of time conversions
Hours/Day
(24–hour day)
Hours/ Week Minutes/ Week Percent of Time
.24 1.68 100.8 1
.48 3.36 201.6 2
28 Key Capacity Advisor concepts