Error: Detected that the vSAN cluster is network partitioned during on-disk format upgrade pre-check.

Products

• VMware vSAN

Issue/Introduction

• vSAN Skyline Health reports 'Disk format version' alerts.

In "vCenter UI > vSAN Cluster > Monitor > Skyline Health"

• On-disk format upgrade pre-check fails with error:

"In vCenter UI > vSAN Cluster > Configure > Disk Management > Pre-check Upgrade "Detected that the vSAN cluster is network partitioned".

Environment

VMware vSAN (All Versions)

Cause

This issue occurs when a host is present in the cluster but cannot communicate over the vSAN network. This is common when a new host is added to the cluster without the vSAN traffic service being tagged/enabled on any VMkernel adapter.

• vSAN cluster is partitioned with error "All hosts have a VSAN vmknic configured".

Health check "ALL HOSTS HAVE A VSAN VMKNIC CONFIGURED"  is triggered when ESXi hosts in the cluster does not have a VMkernel NIC configured for vSAN traffic.

 

• One of the host has no network configured.

Resolution

• If the host is not intended to be part of the vSAN cluster, remove the host from the cluster before proceeding with the upgrade.

• Follow the below steps to configure the vSAN network.

1. 1. Log in to the vSphere Client.
   2. Navigate to the newly added host > Configure > Networking > VMkernel adapters.
   3. Select the adapter used for vSAN traffic and click Edit.
   4. Ensure vSAN is checked under available services.
   5. Verify the host can vmkping other hosts in the cluster over the vSAN network.
   6. Retry the on-disk format version upgrade pre-check once the network partition issues are fixed on the vSAN cluster.

• • • Navigate to the vSAN cluster.
    • Click the Configure tab.
    • Under vSAN, select Disk Management.
    • Click Pre-check Upgrade  - The upgrade pre-check analyzes the cluster to uncover any issues that might prevent a successful upgrade. Some of the items checked are host status, disk status, network status, and object status. Upgrade issues are displayed in the Disk pre-check status text box.
    • Click Upgrade.
    • Click Yes on the Upgrade dialog box to perform the upgrade of the on-disk format.

Additional Information

Upgrading vSAN Disk Format Using vSphere Client

vSAN Health Service - Cluster Health - Disk format version