Live migration traffic misrouting

Question

Hi all

Live Migration traffic bypasses the 40GbE path

Instead, it flows through management interface

Cluster Manager shows priority correctly set

But stale metric overrides still persist

How can we clear cluster network metric overrides safely using PowerShell ?

Answer 1

Welcome to Microsoft Q&A!

Thank you for providing the detailed information.

Based on your description, if Live Migration traffic continues to use the management network even though the 40 GbE network is configured as the preferred migration path, one possible cause is a manually configured cluster network metric. When a metric is manually assigned, the network's AutoMetric property is set to False, and the cluster continues using the overridden value until automatic metric calculation is restored.

First, review the current network metrics and AutoMetric settings:

Get-ClusterNetwork | Format-Table Name, Metric, AutoMetric, Role

If the network intended for Live Migration shows AutoMetric = False, you can safely remove the manual override by re-enabling AutoMetric:

(Get-ClusterNetwork "Cluster Network Name").AutoMetric = $true

To restore automatic metric assignment for all cluster networks:

Get-ClusterNetwork | ForEach-Object {

    $_.AutoMetric = $true

}

Afterward, verify the updated metric values:

Get-ClusterNetwork | Sort-Object Metric |

Format-Table Name, Metric, AutoMetric, Role

It is important to note that Failover Clustering uses network metrics to determine network preference. A manually assigned metric can cause cluster and migration traffic to use an unexpected network, even when the Cluster Manager GUI appears to show the correct Live Migration priority settings. Re-enabling AutoMetric allows the cluster to recalculate and apply the appropriate network metrics.

After resetting the metrics, validate the following:

1. The 40 GbE network is enabled for Live Migration.
2. The management network is not listed as the preferred migration network.
3. Get-ClusterNetwork displays the expected metric values and AutoMetric = True.
4. A test Live Migration confirms that traffic is flowing through the 40 GbE adapter.

In short, the supported method for clearing stale cluster network metric overrides is to re-enable the AutoMetric property. There is no separate PowerShell cmdlet that specifically removes metric overrides.

For additional information, please visit:

Windows Server Failover Cluster Health Service Troubleshooting Guide - Windows Server | Microsoft Learn Recover a failover cluster without quorum in Windows Server | Microsoft Learn

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