HP Integrity Essentials Global Workload Manager: Workload Management for HP Integrity Virtual Machines

• The maximum amount of CPU resources a virtual machine should have upon borrowing—when the

amount of resources owned is insufficient to handle the current workload, it can borrow up to the

designated amount if resources are available.

In addition, the OwnBorrow policy allows you to set the following:

• Priority—Priority levels are assigned to workloads; gWLM addresses priority levels from highest to

lowest, allocating resources to all requests at a given priority level before considering lower priority

requests. The value of 1 is the highest priority.

• Weight— If, at some priority level, all requests cannot be satisfied, the remaining resources are

distributed so that the total resource allocation for each workload is as near the proportion of its

weight relative to the sum of all the weights as possible.

If gWLM has satisfied all resource requests at all priorities and resources are still available for

allocation, it will distribute the remaining resources by weight. Again, this ensures that the total

resource allocation for each workload is as near the proportion of its weight relative to the sum of

all the weights as possible.

How Virtual Machine Entitlements Map to gWLM Policies

This section describes how Integrity VM entitlements map to gWLM policies. When a virtual machine

is brought under control of gWLM, you must select a pre-defined policy or define a new one for that

workload; there is no default policy that is automatically enforced for the workload. The mapping

discussed in this section describes the gWLM policy that, when enforced, would create allocation

behavior similar to the corresponding virtual machine entitlement. gWLM gives you the opportunity to

set policies that improve the allocation behavior in alignment with your business priorities. You can

then use gWLM real-time and historical reports to assess the performance of the workloads under

those policies and tweak policy settings accordingly.

A virtual machine entitlement maps to a gWLM OwnBorrow policy, as follows:

• The gWLM policy minimum is the minimum allocation of CPU resources (as enforced by

Integrity VM) that a virtual machine needs to keep running. The Integrity VM enforced minimum is

5% of CPU resources and applies to all virtual machines. The gWLM policy minimum is then

calculated as 5% of the number of vCPUs, expressed as a decimal fraction. For example, the policy

minimum for a virtual machine with two vCPUs is:

2 vCPUs * 0.05 = 0.10 cores

• The gWLM policy owned amount is the virtual machine entitlement amount based on the number

of vCPUs; for example, a virtual machine with 2 vCPUs and a 25% entitlement would have a

gWLM owned amount of:

2 vCPUs * 0.25 = 0.50 cores

• The gWLM policy maximum is based on the CPU resources required by, and reserved for, the

VM Host, which is 1% of every physical CPU. Therefore, the gWLM policy maximum is calculated

by subtracting 1% for every configured vCPU from the total number of configured vCPUs. For

example, the gWLM policy maximum allocation for a virtual machine with 1 vCPU is:

1 vCPU – (0.01 * 1 vCPU) = 0.99 cores

For a virtual machine with 3 vCPUs, it would be:

3 vCPUs – (0.01 * 3 vCPUs) = 2.97 cores

When viewing Integrity VM resources from gWLM management facilities, the displayed minimum,

size, and maximum values are calculated in the same manner as the minimum, owned, and maximum

amounts. (For an example, see the historical utilization graph in “Viewing the Behavior of the Virtual

Machine Workloads Under gWLM Control” on page 9.)

Table 1 shows how various virtual machine configurations could be defined as gWLM OwnBorrow

policy configurations based on the calculations used above. The first two columns indicate the vCPUs