The Move to Virtualization

Implementing Forward-Thinking Change

Three years ago, the Information Technology Department (ITD) began a server virtualization project.  Virtualization is a technology that uses a cluster of physical machines and specialized software to run multiple virtual servers within one physical environment.

A modern data center, like the City’s, runs hundreds of servers. They create heat, fill up the computer racks and cost a lot more than your average home computer.  Virtualizing servers solves these issues.  A cluster of a dozen physical servers running the virtualization software can host hundreds of virtual servers.  This greatly reduces problems with heat and space along with reducing cost.  Instead of buying a new server to host a new software system, a virtual server is created. The ITD now has more virtual servers than physical servers, creating a more stable, more reliable and more easily restored data center. 

Virtualization offers other advantages as well:

·         Since the virtual server exists as software, it can be backed up completely in much the same way a file is backed up and it can be restored just as easily.

·         Where a hardware failure on a physical system means that the server is unavailable until a secondary server is brought online, or a replacement server can be built, the software that manages the virtual environment can automatically move the virtual server to another section of the physical environment in the event of a hardware failure. The result is no downtime for the users. The failed hardware can be replaced without shutting down the whole system.

·         Since new hardware doesn’t have to be purchased to add a new server, the ITD can respond quickly to requests for new servers.  Rapid deployment means that a new system can begin the implementation phase in hours instead of weeks.

·         In the event of a disaster affecting the data center, recovery time is dramatically reduced.  Instead of setting up hundreds of physical servers, the server administration team sets up the 12 to 20 servers that comprise the virtual hosting cluster, then restore all the backed up virtual machines.

As an example of these advantages, the ITD recently moved the Tucson Police Computer Aided Dispatch (CAD) system to the virtual environment.  The previous, physical, system had two database servers, a primary and a secondary.  If the secondary server was not kept in sync with the primary server, the City was at risk.  A failure of the primary could not have been replaced with the secondary as intended.  Virtualization eliminates this risk by allowing easy and quick "snapshots” of the primary server to be made. These snapshot backups can be used to rapidly replace, or even duplicate, the primary server. The migration to virtual servers has improved the reliability and availability of the Police dispatch system, contributing to the overall improvement of public safety in Tucson.

The ITD is also currently involved in a desktop virtualization project.  In the same way that the server virtual cluster hosts many virtual servers, the desktop cluster would host desktop virtual machines used by the City’s employees. In the initial phase, this project allows the City to reuse 1000 older desktops without having to purchase new ones.  This project has many of the same cost and resource advantages as the server virtualization project, creating a more stable, reliable and sustainable desktop environment for the future.  In addition, this will provide for consistency at the desktop level, easier installation and removal of software and increased performance and efficiency.  By the end of December 2015, we will have 1000 virtual desktops and plan to increase that number over the next few years.