What is a NUMA boundary?
“Non-Uniform Memory Access (NUMA) is a computer memory design used in Multiprocessing, where the memory access time depends on the memory location relative to a processor.
How does vNUMA work?
When a virtual machine is sized larger than a single physical NUMA node, a vNUMA topology is created and presented to the guest operating system. This virtual construct allows a workload within the virtual machine to benefit from physical NUMA, while continuing to support functions like vMotion.
Does Corespersocket affect performance?
To summarize, this test demonstrates that changing the corespersocket configuration of a virtual machine does indeed have an impact on performance in the case when the manually configured virtual NUMA topology does not optimally match the physical NUMA topology.
What is NUMA autosize maxPerVirtualNode?
The advice of setting numa.autosize.vcpu.maxPerVirtualNode in the book is to propagate the virtual NUMA topology to the guest OS. This is typically recommended for VMs that exceed the memory capacity of a NUMA node while being able to all the vCPUs in a single NUMA node.
What is NUMA settings?
NUMA (non-uniform memory access) is a method of configuring a cluster of microprocessor in a multiprocessing system so that they can share memory locally, improving performance and the ability of the system to be expanded. NUMA is used in a symmetric multiprocessing ( SMP ) system.
In which of the below scenarios vNUMA is enabled by default on a virtual machine?
vNUMA is enabled by default once the vCPU count is 9 or more AND the vCPU count exceeds the number of physical core count. You can use the numa. vcpu. min setting when your NUMA nodes and VM vCPU configurations are smaller than 8 and you want to expose vNUMA topology to the guest OS.
How many sockets can a CPU have?
A normal PC only have one socket. Cores are the number of CPU-cores per CPU capsule. A modern standard CPU for a standard PC usually have two or four cores. And some CPUs can run more than one parallel thread per CPU-core.
What is hyper threading in VMware?
Hyperthreading technology allows a single physical processor core to behave like two logical processors. The processor can run two independent applications at the same time. Hyperthreading technology allows a single processor core to execute two independent threads simultaneously.
What advanced vnuma settings do I need to change?
While there are many advanced vNUMA settings, only in rare cases do they need to be changed from defaults. Always configure the virtual machine vCPU count to be reflected as Cores per Socket, until you exceed the physical core count of a single physical NUMA node OR until you exceed the total memory available on a single physical NUMA node.
How do I determine my NUMA node boundaries?
Microsoft provides the following guidance to help calculate this: “ In most cases you can determine your NUMA node boundaries by dividing the amount of physical RAM by the number of logical processors (cores). It is recommended that you read the following articles:
What is the Numa spanning setting on the host?
Virtual NUMA configuration. NUMA spanning setting on the host must be enabled when you have virtual machines that are large enough to be split between two or more physical NUMA nodes. NUMA spanning setting can be disabled, but in that case the virtual machine must fit entirely within a single physical NUMA node,…
How does the Numa scheduler auto-sizes the vnuma clients?
If multiple vNUMA clients are created, the NUMA scheduler auto-sizes the vNUMA clients. By default, it equally balances the number of vCPUs across the least amount of NUMA clients. Autosizing is done on the first boot of the virtual machine. It sizes the NUMA client as optimally as possible regarding the host it boots.