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23.9. NUMA Node Tuning

After NUMA node tuning is done using virsh edit, the following domain XML parameters are affected:

<domain>
  ...
  <numatune>
    <memory mode="strict" nodeset="1-4,^3"/>
  </numatune>
  ...
</domain>

Figure 23.11. NUMA node tuning

Although all are optional, the components of this section of the domain XML are as follows:

Table 23.6. NUMA node tuning elements

Element Description
<numatune> Provides details of how to tune the performance of a NUMA host physical machine by controlling NUMA policy for domain processes.
<memory> Specifies how to allocate memory for the domain processes on a NUMA host physical machine. It contains several optional attributes. The mode attribute can be set to interleave, strict, or preferred. If no value is given it defaults to strict. The nodeset attribute specifies the NUMA nodes, using the same syntax as the cpuset attribute of the <vcpu> element. Attribute placement can be used to indicate the memory placement mode for the domain process. Its value can be either static or auto. If the <nodeset> attribute is specified it defaults to the <placement> of <vcpu>, or static. auto indicates the domain process will only allocate memory from the advisory nodeset returned from querying numad and the value of the nodeset attribute will be ignored if it is specified. If the <placement> attribute in vcpu is set to auto, and the <numatune> attribute is not specified, a default <numatune> with <placement> auto and strict mode will be added implicitly.