vSAN Host unable to enter maintenance mode due to vSAN connectivity

Products

• VMware vSAN

Issue/Introduction

When placing a vSAN host in to maintenance mode with either "Ensure Accessibility" or "Full Data Evacuation" the task fails with the following message:

"Host unable to enter maintenance mode due to vSAN connectivity"

Environment

VMware vSAN

Cause

When you place a vSAN host in to maintenance mode with "Ensure Accessibility" or "Full Data Evacuation" this requires the host to validate object/cluster health states to confirm if any potential data needs to move off the host to retain availability.  This requires proper communication to all hosts in the cluster.

If the vSAN network for this host is inconsistence or unavailable the maintenance mode activity will fail with the message "Host unable to enter maintenance mode due to vSAN connectivity"

Resolution

Validate the host(s) vSAN network by ensuring its up and can communicate with the rest of the vSAN cluster.  Please refer to the following on how to Troubleshooting the vSAN Network

If the host needs to be placed into maintenance mode ASAP and the cluster and all objects are healthy you can use the "No Data Migration" option. However use this option with caution as it can potentially lead to a data outage until such time as the host comes out of maintenance mode. 

It's always best to resolve the networking issue first if possible.