6.5.1

Table Of Contents
The vSphere Web Client lets you specify the following options.
NUMA Node Affinity
When you set this option, NUMA can schedule a virtual machine only on the
nodes specied in the anity.
CPU Affinity
When you set this option, a virtual machine uses only the processors
specied in the anity.
Memory Affinity
When you set this option, the server allocates memory only on the specied
nodes.
A virtual machine is still managed by NUMA when you specify NUMA node anity, but its virtual CPUs
can be scheduled only on the nodes specied in the NUMA node anity. Likewise, memory can be obtained
only from the nodes specied in the NUMA node anity. When you specify CPU or memory anities, a
virtual machine ceases to be managed by NUMA. NUMA management of these virtual machines is eective
when you remove the CPU and memory anity constraints.
Manual NUMA placement might interfere with ESXi resource management algorithms, which distribute
processor resources fairly across a system. For example, if you manually place 10 virtual machines with
processor-intensive workloads on one node, and manually place only 2 virtual machines on another node, it
is impossible for the system to give all 12 virtual machines equal shares of systems resources.
Associate Virtual Machines with Specific Processors
You might be able to improve the performance of the applications on a virtual machine by pinning its virtual
CPUs to xed processors. This allows you to prevent the virtual CPUs from migrating across NUMA nodes.
Procedure
1 Find the virtual machine in the vSphere Web Client inventory.
a To nd a virtual machine, select a data center, folder, cluster, resource pool, or host.
b Click the VMs tab.
2 Right-click the virtual machine and click Edit .
3 Select the Virtual Hardware tab, and expand CPU.
4 Under Scheduling Anity, set the CPU anity to the preferred processors.
N You must manually select all processors in the NUMA node. CPU anity is specied on a per-
processor, not on a per-node, basis.
Associate Memory Allocations with Specific NUMA Nodes Using Memory
Affinity
You can specify that all future memory allocations on a virtual machine use pages associated with specic
NUMA nodes (also known as manual memory anity).
N Specify nodes to be used for future memory allocations only if you have also specied CPU anity.
If you make manual changes only to the memory anity seings, automatic NUMA rebalancing does not
work properly.
Procedure
1 Browse to the virtual machine in the vSphere Web Client navigator.
2 Click the  tab.
3 Click , and click VM Hardware.
vSphere Resource Management
112 VMware, Inc.