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Table Of Contents
Virtual NUMA Controls
For virtual machines with disproportionately large memory consumption, you can use advanced options to
override the default virtual CPU settings.
You can add these advanced options to the virtual machine configuration file.
Table 151. 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 affect the virtual NUMA topology
unless numa.vcpu.followcorespersocket is configured.
1
numa.vcpu.maxPerVirtualNode
Determines the number of virtual NUMA nodes by splitting the
total vCPU count evenly with this value as its divisor.
8
numa.autosize.once
When you create a virtual machine template with these
settings, the settings 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 configured number of virtual
CPUs on the virtual machine is modified 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 scientific 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.
Note 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.
vSphere Resource Management
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