As part of planning configuration changes, you
can also consider your service level objectives or quality of service
goals.
The following utilization graph shows only one
month of data; longer periods of data provide an increasingly accurate
picture of resource usage.
In this example, an allocation of three CPU cores is assumed,
rather than the four cores initially available in this exercise. Even
this reduction may not provide the best fit, as the vast majority
of the work (90%) is completed with less than .5 of one core, and
99% of the work is completed with one core.
For example, as shown in Figure 2-5, CPU utilization has one peak at 1.7 CPU cores,
with many lower peaks. If you configure your system to always meet
the demand of this single 1.7-CPU peak, and you do not adjust the
CPU allocation, a significant fraction of the CPU allocation in this
example would go unused most of the time. Depending on your quality
of service goals, you may decide that a different configuration can
better use the resources available. Further experimentation in Capacity
Advisor with resource allocations, consolidations, and utilization
limits will help you arrive at the best fit for these workloads.
With Capacity Advisor's visualization and reporting tools,
you can make a considered estimate of server resource utilization
using different scenarios and easily refine allocations by tweaking
values in the scenarios. Such estimates can help you minimize overspending
for capacity you use rarely, and maximize utilization of your systems
to ensure that your systems have the capacity needed at the level
you require.
Printable version
