ESXi Rollback

So if you patch an ESXi host, and then realise that actually you want to roll back to the pre patch version, this is possible.

As ESXi is basically just firmware, each time you patch it, the whole thing is replaced. Fortunately, before patching, a backup of the current version is taken and stored. So to roll back to the previous version, just press ctrl r when you see the loading hypervisor screen.