Visualizing Virtualization

What is Server Virtualization?
Server virtualization is the process in which many virtual servers, or “guests” are run on a smaller number of physical servers, or “hosts”, using virtualization software, such as VMWare or Microsoft Hyper-V.

Physical Layer
This network  layer consists of the server hardware, or “hosts”, fast switches, and storage typically in the form of SAN (Storage Area Network).

At this layer, all hardware should be redundant :

  • Minimum 3 hosts
  • 2 or more switches
  • Fully redundant storage

Virtualization Layer
At this layer, virtualization software running on the “hosts” such as VMWare of Microsoft Hyper-V emulate or “mimic” server hardware for the virtual “guests.”

Virtual Computing Layer
“Guests” or virtual servers run in the virtual hardware emulated at the Virtualization Layer.  Virtual hardware can be fine tuned for the specific server and applications, and “guests’ can be moved between hosts to balance resources and provide fault tolerance.

Backup and Disaster Recovery
Backup software such as Veeam and Symantec can copy entire virtual servers to tape or disk, or even to offsite locations, allowing virtual servers to quickly be brought back online in other virtual infrastructures should disaster occur.  In addition, SANS can replicate data to other SANS, either onsite or offsite.