One major benefit related to the new architecture of vSphere 6.x is its simple deployment compared to previous versions. While dealing with vCenter 6.7 architectures, the thing to note is that it consists of two main components: the Platform Service Controller (PSC) and the Virtual Center Server (vCenter Server). Each component includes many services that are installed as one unit when the main component is installed. You cannot choose to install particular service individually.
The PCS contains the following services:
- Single Sign-On. Provides secure authentication and single sign-on mehanism cservices to the vSphere software components.
- Lookup Service. A component of vCenter Single Sign On. It registers the location of vSphere components so they can securely find & communicate with each other.
- License Service. Provides common license inventory and management capabilities to all vCenter Server systems.
- VMware Certificate Authority. While configured properly, this service provides signed certificates to ESXi hosts that are added to your vSphere environment.
The vCenter contains the following services:
- PostgreSQL. A PostgreSQL database variant provided by VMware that is used in vSphere and vCloud Hybrid environment.
- vCenter Server service. The core component vCenter. It provides centralized management and operation, resource provisioning and performance evaluation of VMs.
- vSphere Web Client. The tool that let you connect to vCenter Server instances by using a Web browser, using flash player.
- vSphere Client. A new user HTML 5 based interface that lets you connect to vCenter Server instances by using a Web browser.
- vSphere Auto Deploy. A tool that lets your deploy ESXi images by bulk to physical hosts exiting in your environment.
- vSphere ESXi Dump Collector. A tool that let’s you collect VMkernel memory to a disk or a network server in case of critical failure.
- vSphere Syslog Collector. A tool that lets you direct ESXi system logs to a central server (the Syslog Collector) on the network, and aggregate these for better monitoring and troubleshooting.
vCenter Inventory Services have been removed in vCenter 6.7 and is no longer a needed component. If you plan to migrate from vSphere 6.0 or vSphere 6.5 to vSphere 6.7, the upgrade process migrates the data and removes the vCenter Inventory Services.
Both the PSC and vCenter may be installed on a VM or on physical server, on a Windows server or as an appliance. They can be installed on the same box or on different boxes. When installed on the same server, it is referred an Embedded Installation and is typically the best choice for small companies.
An embedded Platform Services Controller installation has a bunch of advantages, and the most apparent ones are:
- The connection between vCenter Server and the PSC is not over the network, so no concern related to connectivity outages.
- If an embedded installation is done on Windows, you’ll have fewer Windows licenses to use.
For larger organizations, you might want to have have better scalability and performance and choose to install the PSC and vCenter on different servers. This is referred as Linked Installation.
Separating the PSC and the vCenter installation provides even more perspectives. If you have more than once vCenter in your site, you can link more than one vCenter to one PSC. This is referred as Enhanced Linked Mode and brings several benefits to the table, like managing your all virtual workloads which are spread across your different vCenters from one single pane while using one set of credentials.
This, as you might have already noticed, is a single point of failure for the PSC. If you have any concern deploying only one PSC in your environment, which admittedly, is legitimate, the recommended architecture in this case is to use two separate PSCs connected through a load balancer to all your vCenter Servers.
VCSA 6.7 Installation Prerequisites
- A downloaded and mounted vCenter Server Appliance Installer.
- An active NTP server for time synchronization.
- An operative compute and storage resource for the appliance deployment.
- A DNS server with properly configured zone, containing forward and reverse DNS records of the vCenter appliance.
vCenter Server 6.7 Installation Steps Overview
The installation is a two stages process. The appliance deployment on the target ESXi host or vCenter is done the first stage. The actual configuration is done in the second stage.
During the first stage of the installation, you will presented by the vCenter Server installer to select a deployment type, where you’ll have to choose between an embedded installation or linked installation.
If you choose an embedded installation, where both PSC and vCenter will be installed on the same box, the installer will deploy the appliance and will prompt you to configure an SSO domain in the second stage.
Once this is done and the installation steps are processed, you will a ready to use vSphere 6.7 environment.
You might want to check below link to see how to deploy an embedded vCenter 6.7 installation.
However, If you want to go ahead with a linked installation, where PSC and vCenter are deployed on different boxes, you will have to install the PSC and create an SSO domain first.
After that, you’ll have to run the installer once again and install vCenter separately, then link it to the already installed PSC by mapping it to the same SSO domain that was created previously.
If you’re interested to see how to install vCenter on Linked Mode, check below article.
Following the same installation steps, you can link more than one vCenter to your PSC in you environment. As such, you will have an enhanced linked mode deployment with a single SSO domain and single administration pane for managing all existing vCenters in your infrastructure.
The screenshot below show two vCenters named P1VC1 and P1VC2 installed linked to the same PSC. Hence, both can be managed from the same console.
vCenter Embedded Linked Mode is supported in vSphere 6.7
On previous versions of vCenter (mainly 6.0), linking an embedded mode installation to any another other type of vCenter installation was not supported. However, this is not the case anymore, as starting from vSphere 6.5 Update 2, you can connect a vCenter Server Appliance with an embedded PSC together to form a domain. Note though that vCenter Embedded Linked Mode is supported only for vCenter appliance based installations, and is not supported for Windows vCenter Server installations.
Having said that, the following use cases are fully supported now and are suitable for most deployments. This is referred as Embedded Linked Mode installation.
This was just an overview about the possible vSphere 6.7 architectures that can be deployed, and we just scratched the surface here. To get more details on this topic, I suggest you head over this link and read the vCenter Server Installation and Setup white paper. It goes in much more details and provides many deployment use cases related to vSphere deployment on single site and on multiple sites.