We have a VM 5.1 environment with 2 hosts configured with HA. We need to upgrade to 5.5 to address some PSOD issues that are known by VM and supposedly resolved with 5.5. VM Tech Support has advised it as better to upgrade than to workaround. We have successfully upgraded vCenter to version 5.5 but are hard pressed to find any upgrade guidelines pertaining to HA and how to upgrade with HA in mind. Since this is a small 2 host environment we would like to do an Interactive Upgrade with CD/USB iso instead of using Update Manager.
Is there guidelines/best practices documentation out there or can anyone give guidance who has done an upgrade when HA is active? Is it as simple as one of these procedures?
1. Do we just shutdown VM Guests, putting both servers into Maintenance mode and upgrade them?
2. Do we remove HA then upgrade as if a normal 2 host environment?
3. Does the upgrade utility recognize HA and deal with it automatically?
4. Do both VM Hosts have to be upgraded before they are both brought back online or can we all HA to fail all Guests over to one, upgrade the other and then failover to upgrade the 2nd?
As you can see there are many things that come into play with HA, which is why it surprises me that there is no reference to it in the upgrade docs.