"host(s) will be incompatible with upgraded vCenter Server" when upgrading to vSphere 6.7 and later

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:
When attempting to upgrade to vSphere 6.7 or 7.0 or later, you may see the message similar to:

 

Host_Name host(s) will be incompatible with upgraded vCenter Server

Environment

VMware vCenter Server 6.7.x
VMware vCenter Server Appliance 6.7.x
VMware vCenter Server 7.0.x

Cause

This issue occurs because:

• vSphere 6.7 do not support ESXi 5.5 and earlier hosts.
• vSphere 7.0 do not support ESXi 6.0 and earlier hosts.

Resolution

To resolve this issue, identify hosts in the inventory causing incompatibility and upgrade the ESXi hosts to the compatible versions or higher.

To Identify the hosts in the inventory causing incompatibility and upgrade the ESXi hosts to compatible versions or higher:

1. Connect to the vCenter Database using appropriate tools
   • For more information on vPostgres interactions, see:
     • Interacting with the vCenter Server Appliance 6.5/6.7/7.0 embedded vPostgres Database
     • Connecting to the embedded vPostgres Database in a Windows installed vCenter Server 6.x
2. Execute the below SQL query to list the name of hosts which are vCenter Server <version>.For example for the vCenter Server 5.5 the query is as below. Modify the query version as be version and execute. 

select dns_name from vpx_host where product_version='5.5.0';

​

​If the host is already in an upgraded version, remove the host from Inventory and add it back to refresh the information
 

Note: If no feature/solution dependency, you may disconnect the host and remove from inventory without any impact to Virtual Machine. Removing objects from vCenter inventory would cause vCenter internal object ID changes and historical performance data to be lost.
Warning: In case of features like (not limited to) vDS, vSAN, Horizon View etc. take appropriate precautions before removing host from inventory. For Assistance contact VMware Support and note this Article ID (52883) in the problem description. For more information, see How to Submit a Support Request. 

3. Upgrade the ESXi host to a compatible or higher version. For more information, see Overview of the vSphere Upgrade Process section in the vSphere Upgrade guide.