Before upgrading to vCenter Server Appliance 6.7, you must prepare your ESXi hosts.


To upgrade vCenter Server Appliance, your ESXi hosts must meet the requirements for upgrade.

  • ESXi hosts must be at version 6.0 or later. Read and follow all best practices when upgrading your hosts to ESXi 6.0 or later. For information on ESXi compatibility, see the VMware Compatibility Guide.
  • Your source and target ESXi hosts must not be in lockdown or maintenance mode, and not part of fully automated DRS clusters.
  • Review your environment's Certificate Authority (CA) signed SSL certificates. To learn about manually reviewing CA signed SSL certificates in a vSphere environment, see Knowledge Base article KB 2111411.


  1. If you have Custom or Thumbprint certificates, see Host Upgrades and Certificates to determine your preparatory steps.
  2. If you have vSphere HA clusters, SSL certificate checking must be enabled.
    If certificate checking is not enabled when you upgrade, vSphere HA fails to configure on the hosts.
    1. Select the vCenter Server Appliance instance in the inventory panel.
    2. Select the Configure tab, and then under Settings select General.
    3. Click Edit.
    4. Select SSL settings.
      Verify that vCenter Server requires verified host SSL certificates is selected.


Your ESXi hosts are ready for the vCenter Server Appliance upgrade.