Unable to Reconfigure Windows Server 2016 Failover Cluster After VM Recovery from Backup

Products

• VMware vSAN

Issue/Introduction

After recovering two Windows Server 2016 virtual machines from backup, the Failover Cluster Manager fails to recognize shared disks during the cluster reconfiguration process.

Symptoms

• Disks are visible in Windows Disk Management.
• Disks can be added to the VM but do not appear in "Add Disk" in Failover Cluster Manager. 

"No disks suitable for cluster disks were found. For diagnostic information about disks available to the cluster, use the Validate a Configuration Wizard to run Storage tests."

• PowerShell reports no clustered disks available.

• Issue occurs regardless of whether the disk is new or existing.

Environment

VMware ESXi 7.x
VMware ESXi 8.x

Cause

The issue is due to unsupported virtual SCSI controller configuration for shared disks:

• All shared disks were attached to SCSI Controller 0 with Bus Sharing set to None.
• This setup is not supported for WSFC in a vSphere environment.

According to Microsoft Windows Server Failover Clustering (WSFC) with shared disks on VMware vSphere 7.x: Guidelines for supported configurations :

• Shared VMDKs must be connected to a separate SCSI controller with Bus Sharing set to Physical.
• Boot and non-shared disks must use a different SCSI controller with Bus Sharing set to None.
• Mixing shared and non-shared disks on the same controller is unsupported.
• Multi-writer flag should not be used for WSFC configurations.

Resolution

Workaround

• Power off both VMs
• Add a new SCSI controller to each VM and set Bus Sharing to Physical.
• Move all shared disks to this new controller (e.g., SCSI Controller 1).
• Power on the VMs and validate disk visibility in Failover Cluster Manager.
  • Shared disks are now visible and can be added to the cluster.

If the issue still persists, involve Microsoft vendor for further troubleshooting.