All required hosts are in maintenance mode warnings on vCenter server.

Products

• VMware vSAN
• VMware vSphere ESXi 8.0

Issue/Introduction

This article provides steps to workaround when you are seeing an alert for one or more existing hosts. 
Under the 'Quickstart' option alert is seen with the message "All required hosts are in maintenance mode"

Environment

vSAN 7.x
vSphere 7.x / 8.x

Cause

Existing Hosts were not added/configured using the Quickstart option. 

Resolution

To fix the warnings, the below workaround can be applied.

1. Place the impacted host into Maintenance with Ensure accessibility. 

2. Drag and drop the host into the Datacenter.

3. Navigate to the cluster in the vSphere Client.

4. Click the Configure tab, and select Configuration > Quickstart.

5. On the Add hosts card, click Add to open the Add hosts wizard.

   1. On the Add hosts page, enter information for new hosts, or click Existing hosts and select from hosts listed in the inventory.

   2. On the Host summary page, verify the host settings.

   3. On the Ready to complete page, click Finish.

6. On the Cluster configuration card, click Configure to open the Cluster configuration wizard.

7. Configure or keep the existing settings in case the host is already configured and proceed to Review, click Finish.

8. Validate the QuickStart and Skyline health post host is added successfully.

Note: For a non-vSAN host cluster, simply removing an ESXi host from the cluster and adding it back may not resolve the issue. It is required to create a "New Cluster" and then move the ESXi hosts from the existing cluster to the new one using the “Quickstart” option to clear the warning.

Additional Information

The below article has more information on the QuickStart warnings.

vSAN Health Service - All required hosts are in maintenance mode