vSphere 6.7 Infrastructure

The components that make up vSphere

Tech Notes
2 min readMay 9


The basic components of vSphere are the hypervisor (ESXi), vCenter Server and its plugins, as well as the supporting databases and host management agents. VMs are run on these hypervisors, and vCenter is the management layer. Virtual data centers can be created using vCenter. To manage or utilize the virtual data center, every other solution interfaces with Center.

The following software components form the foundation of a vSphere environment:

  • Hypervisor: VMware ESXi
  • Core management software: VMware vCenter server and its components
  • Patch management software: VMware Update Manager

With vSphere 6.0, VMware started bundling essential services like single sign-on, inventory service, and certificate management into one manageable component, the Platform Services Controller (PSC). Each component had its own installer in versions prior to vCenter 6.0 for Windows, all of these components had individual installers, making it possible for them to be either installed on the same machine as the vCenter or installed onto separate machines. Therefore, it became necessary to protect and manage more than one virtual or physical machine running Windows. It also made upgrading and troubleshooting cumbersome. Bundling them together onto the same Windows machine or deploying them as an appliance made management and upgrade a breeze.

PSC can be deployed as a separate virtual machine (Windows/VCSA) or as an embedded component within the VCSA. As of vSphere 6.7, external PSCs are no longer required.

PSC includes an authentication server component called SSO. An authentication gateway accepts authentication requests from registered components and validates credential pairs against identity sources added to the SSO server. As soon as they have successfully authenticated, they are provided with security tokens for future authentication exchanges.

VUM (vCenter Update Manager) is used to upgrade or patch a vSphere environment. In most cases, it is used to install patches or upgrade ESXi. It can also upgrade VMware tools and virtual machine hardware. By default, the solution is integrated into the vCenter Appliance.

VMware Certificate Authority (VMCA) is the default issuing authority for vSphere Certificate Manager.

VMware Licensing Service provides licensing information for all VMware products that work with PSC/vCenter. PSCs in the same SSO domain replicate license information.

vCenter’s database is its source of truth. A database connection is required for vCenter to function.