NUMA optimization in XenCenter

Last published : Oct 01, 2026
Related information
Monitoring System Performance

Overview

XenCenter shows NUMA optimization status for virtual machines (VMs) on XenServer 9 hosts. Use XenCenter to verify placement and to visualize NUMA-related metrics after you enable them.

Where to view NUMA status

  • VM General tab: Shows whether the VM is NUMA-optimized.
  • VM Performance tab: Shows per-VM RRD data sources for NUMA and scheduling after you enable them.

Indicators

  • NUMA nodes = 1: The VM is optimized and uses a single NUMA node.
  • NUMA nodes > 1: The VM memory is spread across multiple NUMA nodes. The VM is not optimized.

Enable metrics

Per-VM NUMA-related metrics are disabled by default. To enable them:
  1. Select the VM in the Resources pane.
  2. On the Performance tab, select Actions > New graph...
  3. Click Show data sources > Disabled to include disabled data sources in the list.
  4. From the list of data sources select the check boxes of the data sources you want to enable such as "NUMA nodes", "vCPUs runnable any" and so on.
  5. Click Enable to enable the recording of the selected metrics on the server.
  6. Click Save to create the new graph with the selected datasources.

Guidance and considerations

Performance gains from NUMA optimization depend on:
  • Workload and application profile in the VM.
  • Benchmark or metric used to measure latency and throughput.
  • CPU architecture and generation.
If your use case requires strict single-node placement and the VM cannot fit on one NUMA node, resize the VM memory to fit within a single node or adjust host memory allocation to make a single-node placement possible.