Disk Witness

Question

What is the proper and safe procedure to move a Disk Witness (shared storage–based quorum witness) from one node to another in Windows Server 2025 Failover Cluster Manager.

Answer 1

Hello Jim Geis,

Following up on your issue, you might be attempting to move the disk resource independently, but in Windows Server Failover Clustering, including the 2025 release, the Disk Witness is architecturally bound to the Core Cluster Group. This design guarantees that the quorum resource and the core cluster identity are arbitrated together. Attempting to isolate and move just the quorum disk using a command like Move-ClusterResource will be rejected by the cluster service to prevent splitting core resources across different nodes and destabilizing quorum integrity. Therefore, the procedure I provided earlier (executing the Move-ClusterGroup -Name "Cluster Group" -Node command in an elevated PowerShell session, or navigating the Failover Cluster Manager GUI via More Actions to select Move Core Cluster Resources) remains the strict Microsoft best practice. This method ensures the cluster service cleanly manages the SCSI-3 Persistent Reservation release on the source node and the claim on the destination node without interrupting the overall vote tally. You can confidently verify the successful transition by monitoring the cluster operational logs for Event ID 1205, which confirms the core group was successfully brought online on the target node.

Hope this answer brought you some useful information. If it has, please consider accepting the answer so that other people sharing the same issue would benefit too. Thank you :)

VP

Answer 2

Hello Jim Geis,

In Windows Server 2025 Failover Clustering, the cluster service dynamically arbitrates witness ownership using SCSI-3 Persistent Reservations to maintain quorum. Manual intervention is almost never required unless you are actively troubleshooting storage fabric anomalies, isolating a faulty Host Bus Adapter, or resolving persistent reservation deadlocks.

To safely transfer the Disk Witness, you must move the entire core Cluster Group. Launch an elevated PowerShell session and execute Move-ClusterGroup -Name "Cluster Group" -Node <TargetNodeName>. This cmdlet handles the graceful transition of the SCSI-3 PRs, offlining the disk on the source node and bringing it online on the destination node without impacting the cluster's voting integrity . If you prefer the GUI, right-click the cluster name in Failover Cluster Manager, navigate to More Actions, select Move Core Cluster Resources, and choose Select Node.

Before you proceed, I need to know why you are manually forcing this ownership change. Are you actively troubleshooting SAN fabric issues, experiencing MPIO path drops, or seeing Event ID 1069 or 1564 in the cluster events? Because the cluster handles witness arbitration automatically, forcing a move without diagnosing the underlying storage connectivity via the Get-ClusterLog -Destination C:\logs command might obscure a deeper infrastructure problem that needs to be addressed at the storage controller level.

Hope you found something useful in the answer. If it helped you get more insight into the issue, please consider accepting it. Thank you and have a nice day!

VP

Answer 3

To move a Disk Witness in a Windows Server Failover Cluster, you should follow these general steps:

1. Remove the Disk Witness from the Current Node: In Failover Cluster Manager, navigate to the cluster, right-click on the Disk Witness resource, and select "Remove". This will detach the witness from the current node.
2. Prepare the New Node: Ensure that the new node has access to the shared storage where the Disk Witness is located. The shared disk must be configured correctly and should not be assigned a drive letter or used for any other purposes.
3. Add the Disk Witness to the New Node: In Failover Cluster Manager, right-click on the cluster name, select "More Actions", and then choose "Configure Role". Follow the wizard to add the Disk Witness back, ensuring you select the correct shared disk.
4. Verify Configuration: After adding the Disk Witness to the new node, verify that it is online and functioning correctly. Check the cluster's quorum configuration to ensure that the Disk Witness is contributing to the quorum voting process.
5. Test Failover: Finally, perform a test failover to ensure that the cluster operates correctly with the Disk Witness on the new node.

These steps should help ensure a proper and safe transition of the Disk Witness between nodes in your Windows Server Failover Cluster.