VxRail: Upgrading a Horizon View (VDI) Cluster

Introduction

When upgrading a VxRail cluster that is being used to host a Horizon View VDI Infrastructure, additional manual steps must be performed.
On a regular VxRail cluster, the LCM logic takes care of placing the hosts in MM automatically.
On a Horizon View Environment, depending on the type/version of the deployment additional steps might be needed in order to place the host in MM. This is due to the fact that when Instant Clones are provisioned, the parent VM is created on all the hosts in the cluster and are bound to the hosts so they cannot be vmotioned.
 

Resolution

Consult VMware KB Entering and exiting maintenance mode for an ESXi host that has Horizon instant clones regarding the settings that have to be changed.
The settings have to be applied sequentially to the hosts, so first change the setting on host 1, prior to starting the VxRail upgrade.
Once the VxRail upgrade starts and the settings on the first host have been changed, the LCM can put the first host in MM and upgrade it.
Once it finishes, the InstantClone.Maintenance annotation value has to be set to the original value.
Repeat the steps for all the hosts until the upgrade is complete.
If the upgrade fails between two hosts due to a timeout on the Maintenance Mode, just retry the upgrade.