vCenter Server 6 has some fundamental architectural changes compared to vCenter Server Server 5.5. The multitude of components that existed in vCenter Server 5.x has been consolidated in vCenter Server 6 to have only two components vCenter Management Server and Platform Services Controller, formerly vCenter Server Single Sign-On.
The Platform Services Controller (PSC) provides a set of common infrastructure services encompassing
- Single Sign-On (SSO)
- Licensing
- Certificate Authority
The vCenter Management Server consolidates all the other components such as Inventory Service & Web Client services along with its traditional management components. The vCenter Server components can be typically deployed in with either embedded or external PSC. Care should be taken to understand the critical differences between the two deployment models. Once deployed one cannot move from one mode to another in this version.
Deployment Models:
vCenter Server with Embedded PSC:
The embedded PSC is meant for standalone sites where vCenter Server will be the only SSO integrated solution. In this case a replication to another PSC is not necessary.
- Sufficient for most environments. Easiest to deploy and maintain
- Aimed at minimizing fault domains. Use in conjunction with only one of VMware Product or Solution.
- Multiple standalone instances supported
- Replication between embedded instances not supported
- Supports Windows & Appliance
Embedded mode vCenter Server 6
vCenter Server with External PSC:
In this configuration the PSC is external to the vCenter Server. This configuration allows multiple vCenter Servers to link to a PSC.
- Recommend this if deploying/growing to multiple vCenter Server instances that need to be linked
- Reduces footprint by sharing Platform Services Controller across several vCenter Servers
- Deploy more than one PSC to provide resilience within the environment
- Supports Windows & Appliance
vCenter Server 6 with External PSC
Source: Superb post written by Mohan Potheri
