A fairly common deployment topology with vSphere 5.5 was to use the ‘Simple Install’ method which placed all the individual vCenter components onto a virtual or physical vCenter Server.
This would then hook into an external virtual or physical SRM server. With Linked Mode used for ease of management.
As well as the normal considerations with vSphere upgrades around:
- Hardware compatibility and firmware versions
- Component interoperability
- Database compatibility
- vCenter Plugins
- VM Hardware & Tools
- Backup interoperability
- Storage interoperability
We now have to consider the Platform Services Controller.
Platform Services Controller
The Platform Services Controller is a group of infrastructure services containing vCenter Single Sign-On, License Service, Lookup Service and VMware Certificate Authority.
vCenter SSO Provides secure authentication services between components using secure token exchange. Rather than relying on a third party such as Active Directory.
vSphere License Provides a common license inventory and management capabilities
VMware Certificate Authority Provides signed certificates for each component.
The issue arises with vCenter SSO component, as most people would have opted for vSphere 5.5 ‘Simple Install’. This means you end up with an embedded Platform Services Controller, see ‘How vCenter Single Sign-On Affects Upgrades‘
The embedded Platform Services Controller topology has been deprecated by VMware, see ‘List of Recommended Topologies for VMware vSphere 6.0.x‘. This is also confirmed in VMware Site Recovery Manager 6.1 documentation under ‘Site Recovery Manager in a Two-Site Topology with One vCenter Instance per Platform Services Controller‘
What Does This Mean?
Due to the architectural changes between vSphere 5.5 and 6. You cannot perform an in-place upgrade from vSphere 5.5 to vSphere 6 if you originally selected ‘Simple Install’ as you will end up with an deprecated topology.
The only choice will be a new vCenter 6 using the topology shown below.
This also means you will need to deploy an extra two virtual machines to support this configuration.