6.0.1

Allocate CPU Resources
To manage workload demands, you can change the amount of CPU resources allocated to a virtual machine
by using the shares, reservations, and limits settings.
A virtual machine has the following user-defined settings that affect its CPU resource allocation.
Limit
Places a limit on the consumption of CPU time for a virtual machine. This
value is expressed in MHz or GHz.
Reservation
Specifies the guaranteed minimum allocation for a virtual machine. The
reservation is expressed in MHz or GHz.
Shares
Each virtual machine is granted a number of CPU shares. The more shares a
virtual machine has, the more often it gets a time slice of a CPU when there is
no CPU idle time. Shares represent a relative metric for allocating CPU
capacity.
Procedure
1 Right-click a virtual machine in the inventory and select Edit Settings.
2 On the Virtual Hardware tab, expand CPU, and allocate the CPU capacity for the virtual machine.
Option Description
Reservation
Guaranteed CPU allocation for this virtual machine.
Limit
Upper limit for this virtual machine’s CPU allocation. Select Unlimited to
specify no upper limit.
Shares
CPU shares for this virtual machine in relation to the parent’s total. Sibling
virtual machines share resources according to their relative share values
bounded by the reservation and limit. Select Low, Normal, or High, which
specify share values respectively in a 1:2:4 ratio. Select Custom to give each
virtual machine a specific number of shares, which express a proportional
weight.
3 Click OK.
Configure Processor Scheduling Affinity
The Scheduling Affinity option gives you detailed control over how virtual machine CPUs are distributed
across the host's physical cores. The option supports hyperthreading if hyperthreading is enabled. ESXi
generally manages processor scheduling well, even when hyperthreading is enabled. These settings are
useful only for fine-tuning critical virtual machines.
Using CPU affinity, you can assign a virtual machine to a specific processor. This assignment allows you to
restrict the assignment of virtual machines to a specific available processor in multiprocessor systems.
This setting does not appear for virtual machines in a DRS cluster or when the host has only one processor
core and no hyperthreading.
For potential issues with CPU affinity, see the vSphere Resource Management documentation.
Prerequisites
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Verify that the virtual machine is turned off.
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Verify that the virtual machine does not reside in a DRS cluster.
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Verify that the host has more than one physical processor core.
vSphere Virtual Machine Administration
98 VMware, Inc.