In this post we will try to understand the vCenter Server roles along with components included with these roles.
vCenter Server:
VMware vSphere has two important layers as listed below.
- ESXi – A Hypervisor
- ESXI layer is also referred as virtualization layer that provides virtualization platform.
- vCenter Server – For Centralized Management
- The vCenter Server is referred as management layer that provides centralized management for virtual environment.
- Apart from centralized management, vCenter server when integrated into infrastructure adds additional distributed features such as vSphere HA, Fault Tolerance, vMotion, DRS and so on.
- Without vCenter Server these features are not available.
The vCenter Server in earlier version such as 5.x had server roles as:
- Single Sign On
- Web Client
- Inventory Service
- vCenter Service
With vSphere 6.0, vCenter server roles comes with only two primary roles as mentioned below.
- Platform Services Controller (PSC)
- vCenter Server
Each of these two roles can be installed on a single system, this deployment is called as embedded deployment. You can also install PSC on one node and vCenter on another, this is called as distributed deployment. If you go for distributed deployment, you need to follow install order. You will need to install PSC first and then vCenter Server on another server.
PSC and vCenter roles contains multiple sub-roles as described in below diagram.
Platform Services Components:
SSO:
Single sign-on service for vSphere environment.
VMDIR:
VMware directory service that provides domain environment. Earlier we used to get vsphere.local as domain, in this version you can change the name of domain that you want to use.
License Service:
Provides centralized license management for vSphere environment. Also you can manage the licenses for other VMware solutions such as vSAN that are integrated with vSphere environment.
VMCA:
Inbuilt Certificate authority server that generates certificates for ESXi server and solution users in virtual environment.
VECS:
Abbreviation for Endpoint certificate store. It stores certificates granted by VMCA to solution users. Certificates granted to ESXi servers are not stored in VECS as they are stored on respective ESXi servers.
NOTE:
Prior to vsphere 6.0 ESXi server communicates with vCenter server using Thumbprints, However in this release thumbprint mode is not used instead certificates are used for the same.
Lookup Service:
It is also referred as service registry. It holds infromation about products that are registered and integrated with vSphere environment.
Permissions and Tags:
Permission management and Tags (Custom attributes in old versions) is taken care by PSC.
vCenter Server Components:
vCenter service:
The vCenter service for centralized management.
Web client:
Tomcat web server instance that gets installed along with vCenter. It provides web client interface for managing virtual environment.
Inventory Service:
Manages all the inventory items that are stored in vCenter database in virtual environment.
Postgres Database:
Default database for windows as well as appliance based (SLES) vCenter Server if no external databases like Oracle is used. In earlier versions, we used have SQL Express as default database for windows based vCenter server.
Core Dump collector:
For remote collection of core dump (PSOD) data over network from ESXi servers.
Syslog Collector:
For remote collection of logs generated by ESXi servers.
Auto Deploy:
In this release auto deploy service also get configured along with vCenter server installation. Can be used for bulk deployment of network based ESXi installation.
For information on vCenter 6.0 do refer below documents from VMware resources.
vCenter Server and Host Management
vCenter Server Appliance Configuration