6.5.1

If the virtual NUMA topology needs to be overridden, see “Virtual NUMA Controls,” on page 111.
N Enabling CPU HotAdd will disable virtual NUMA. See hps://kb.vmware.com/kb/2040375.
Virtual NUMA Controls
For virtual machines with disproportionately large memory consumption, you can use advanced options to
override the default virtual CPU seings.
You can add these advanced options to the virtual machine conguration le.
Table 14‑1. Advanced Options for Virtual NUMA Controls
Option Description Default Value
cpuid.coresPerSocket
Determines the number of virtual cores per virtual CPU
socket. This option does not aect the virtual NUMA
topology unless numa.vcpu.followcorespersocket is
congured.
1
numa.vcpu.maxPerVirtualNode
Determines the number of virtual NUMA nodes by
spliing the total vCPU count evenly with this value as
its divisor.
8
numa.autosize.once
When you create a virtual machine template with these
seings, the seings remain the same every time you
then power on the virtual machine with the default value
TRUE. If the value is set to FALSE, the virtual NUMA
topology is updated every time it is powered on. The
virtual NUMA topology is reevaluated when the
congured number of virtual CPUs on the virtual
machine is modied at any time.
TRUE
numa.vcpu.min
The minimum number of virtual CPUs in a virtual
machine that are required to generate a virtual NUMA
topology. A virtual machine is always UMA when its
size is smaller than numa.vcpu.min
9
numa.vcpu.followcorespersocket
If set to 1, reverts to the old behavior of virtual NUMA
node sizing being tied to cpuid.coresPerSocket.
0
Specifying NUMA Controls
If you have applications that use a lot of memory or have a small number of virtual machines, you might
want to optimize performance by specifying virtual machine CPU and memory placement explicitly.
Specifying controls is useful if a virtual machine runs a memory-intensive workload, such as an in-memory
database or a scientic computing application with a large data set. You might also want to optimize NUMA
placements manually if the system workload is known to be simple and unchanging. For example, an eight-
processor system running eight virtual machines with similar workloads is easy to optimize explicitly.
N In most situations, the ESXi host’s automatic NUMA optimizations result in good performance.
ESXi provides three sets of controls for NUMA placement, so that administrators can control memory and
processor placement of a virtual machine.
Chapter 14 Using NUMA Systems with ESXi
VMware, Inc. 111