VCF: Workaround for Quorum-Disk Failure Scenario in 2-Node WSFC 2025 Configuration
Source: VMware Blog
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Deji – March 9 2026
Synopsis
Broadcom has published a 10‑minute demo video that shows how to work around a commonly reported failure scenario in 2‑node Windows Server 2025 Failover Clusters (WSFC) when adding or configuring a quorum disk in VMware Cloud Foundation (VCF).
Important: This video demonstrates a workaround for one symptom only. It does not resolve the underlying WSFC 2025 defect that can cause broader quorum/core‑resource transition and failover‑reliability issues.
Applies to
- Windows Server 2025 Failover Clustering (2‑node)
- Shared‑disk / quorum‑disk configurations
- VMware Cloud Foundation deployments (symptoms also reported outside vSphere)
Customer‑reported behavior (field symptom)
Customers have observed WSFC 2025 failure scenarios where the expected quorum/core‑resource behavior breaks down in a 2‑node cluster. Broadcom documented a related failure mode (shutting down an active VM that holds cluster resources when the cluster has no roles can lead to a cluster‑down condition) and notes that Microsoft is actively investigating.
A similar 2‑node quorum/ownership failure has also been reported by customers in non‑VCF environments (including 2‑node configurations on Microsoft Hyper‑V), confirming that the issue is not hypervisor‑specific.
What we’re releasing
- A 10‑minute demo video – shows a repeatable workaround to successfully complete quorum‑disk addition/configuration without triggering the cluster‑failure condition.
- Scope: Workaround for this specific symptom only – it does not claim to “fix WSFC 2025”.
Microsoft mitigation (shipped update and enablement flag)
Microsoft has shipped Windows Server 2025 cumulative updates that customers commonly associate with the mitigation path, including KB5063878 (August 12 2025; OS Build 26100.4946).
Reports on Microsoft‑hosted threads indicate that the effective behavior may require an explicit FeatureManagement override registry value (2005146767) to be set (followed by a restart).
# Verify the update is present
Get-HotFix -Id KB5063878
# Enable the mitigation (run as Administrator)
reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" `
/v 2005146767 /t REG_DWORD /d 1 /f
# Disable the mitigation
reg add "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" `
/v 2005146767 /t REG_DWORD /d 0 /f
# Return to default behavior (remove the override)
reg delete "HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides" `
/v 2005146767 /f
# Restart (required)
Restart-ComputerNotes
- If you are actively experiencing cluster instability during quorum‑disk configuration, start with the workaround shown in the video, then evaluate Microsoft’s shipped mitigation and the override flag in a controlled maintenance window.
- Community reports also describe broader “quorum/core resources don’t transition as expected” scenarios during node maintenance (including patching) in 2‑node WSFC 2025.
- The behavior described in this post does not occur if you use a File Share Witness as the quorum.
References
- Broadcom KB: WSFC 2025 2‑node cluster‑down scenario statement
- Microsoft Q&A: 2‑node WSFC 2025 quorum owner restart causing cluster down
- Microsoft Q&A: Event 1177/quorum‑loss thread incl. FeatureManagement override 2005146767
- Microsoft Support KB: KB5063878 (Windows Server 2025 cumulative update)
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