In vSphere 5.x versions, the most common deployment topology was a vCenter with all the components installed on the same virtual machine. The design choices for using a single virtual machine with all services running on them included:
- Simplicity of management
- Backup and restore, with only a single virtual machine to protect
- Reduction of overall license costs for guest operating system
- Requires less compute resources to run
- Reduced complexity of HA rules (External SSO start first then vCenter)
- Single virtual machine to secure and harden
Depending on the size of the environment, you might see one or many vCenter’s with embedded services. External services such as SRM, vROPs, Horizon View would then hook into the vCenter.
From an architectural standpoint, you knew that deploying a vCenter with embedded services you would cover most if not all future third party deployment scenarios e.g. add on SRM you are covered.
With vSphere 6, this has all changed and I would question if deploying a vCenter with an embedded Platform Services Controller is the right way to go.
Deprecated Topology
VMware KB2108548 shows that a single vCenter with an embedded Platform Services Controller is a supported topology.
Excellent, you might say. But what if I want to add third party services such as SRM in the future? Well the answer to that is you won’t be supported in the future using this topology.
This means that you would need to change the architecture from what was originally deployed to the below to be in a supported configuration.
Changing vCenter 6 into a supported architecture isn’t straight forward. The main gotcha that I’m aware of is that you are unable to change a vCenter using an embedded Platform Services Controller to an external Platform Services Controller. The only way that I’m aware of is to upgrade to vCenter 6.0 U1 and follow VMware KB2113917.
The impact of the following points also needs to be considered when changing from an embedded to external Platform Services Controller:
- SSL Certificates
- Third Party Plugins
- Third Party Applications such as vROPs
- Backup & Restore
- Change Control
- Security and Permissions
Final Thought
vCenter with an embedded Platform Services Controller are applicable to small environments in which you have a static topology with no requirement for enhanced linked mode or integration with external products. Consider the upgrade path from an embedded Platform Services Controller to an external Platform Services Controller.
In any environment where their is a possibility that you will need to integrate vCenter with a third party piece of software such as SRM or vRA or if you require Enhanced Linked Mode then start your architecture with an external Platform Services Controller.
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