By Melissa Palmer

VMware vCenter has long been the brains of any vSphere deployment.  Originally debuting as Virtual Center 1.0 to go along with ESX 2.0, the features and functionality have grown over time.  With the release of vSphere 4, Virtual Center began to be known as vCenter, and it’s version now matched with ESX.  With the release of vSphere 5, we were introduced to the vCenter Server Appliance, a Linux based appliance that is quick and easy to deploy into a VMware vSphere environment.  Now, as vCenter 6.0, vCenter as a whole has evolved to a whole new level.

Windows Install or Appliance?

The vCenter Server Appliance has the same scalability as the Windows based deployment model.  So why would an organization use one over the other?  Windows only shops will most likely lean towards the Windows installable deployment, as organizations may not be comfortable with their vCenter deployment running on a platform they are not familiar with.  In the same vein, SQL only shops will lean towards the Windows installable model, as it supports both SQL and Oracle, while the vCenter Server Appliance only supports Oracle.  Both the Windows and Appliance based deployments are also capable of being supported on the internal PostgreSQL database for smaller deployments.


(Image taken from the What’s New in the VMware vSphere 6.0 Platform Technical White Paper)

Continued Evolution in Architecture

New in the vCenter 6.0 architecture is something called the Platform Services Controller, or PSC.  The PSC handles aspects of vCenter Server like Singe Sign-On (who doesn’t love vSphere Single Sign-On?), licensing, and certificates.  Gone are the days of configuring your licensing in every instance of vCenter you have, as the PSC can be shared across multiple vCenter instances.  By using the PSC, you can also use both Windows installable vCenter and the vCenter Server Appliance in linked mode.

Speaking of multiple vCenters, the former vMotion boundary of the virtual data center has been removed, allowing vMotion across vCenters.  Gone are the days of sacrificing a poor host to bounce around between vCenters to bring virtual machines with it!  This requires Layer 2 connectivity between the vCenter instances, but gives us much more flexibility when designing our vSphere deployments.  The removal of this boundary also comes with another important feature, the ability to completely relocate a virtual machine to another vCenter, wherever it may be, as long as it is within 100ms latency.  I can change host, storage, and network, all non disruptively.  Now, it is all about scale and flexibility.

Protecting Our Assets

vCenter 6.0 also introduces the ability to have a vSphere Fault Tolerance, or FT virtual machine with up to four virtual CPUs and 64 GB of RAM.  Previously, only one virtual CPU was supported, which limited the applications which could be deployed in a FT manner.  FT allows for two virtual machines to be run in sync, so tin the event of something like a host failure, FT will automatically fail over to the second virtual machine, without any outage or loss of data.  While vSphere High Availability (HA), will bring virtual machines back online after a host failure if configured to do so, the virtual machines will still have the brief outage, which is essentially a reboot.  In vCenter 6.0, HA becomes even smarter, with the ability to protect virtual machine components such as storage.  In the event of an All Paths Down or Permanent Device Loss condition (which means you’re going to have a very bad time as an infrastructure administrator), vSphere HA will now restart virtual machines on hots that are not suffering from a storage outage.  In addition, the HA cluster size has doubled, from 32 to 64 nodes, and a huge number of virtual machines, 6,000 from 2,048 are now supported, providing further scalability.


vSphere 6.0 is full of great new features to enable vSphere administrators and architects to further scale their environments, while making them easier to manage.  vSphere has come a long way since the early days when vMotion (and I mean vMotion, not Storage vMotion) was a shiny new toy for vSphere admins to play with, with quirky bugs along with it.  The vSphere platform, as it is now called, as come long way since the early days of ESX, and continue to evolve to meet our needs across our data centers.  Make sure to check out the What’s New in the VMware vSphere 6.0 Platform Technical White Paper to learn more about the great new vSphere 6.0 features.