ing and Enabling Technologies In addition, virtualization saves time for the network manager, eliminating frequent travel to the school systems' 17 locations to physically manage remote servers. The applications are now centrally located and managed in the virtual- ized server with the largest-capacity hard drive. This server is referred to as the Storage Area Network (SAN) because it contains the SAN software and stored applications. Three of the VMware servers without applications communicate with end users. All four VMware servers are networked together in the depart- ment's central data center and operate as a single computer, with the SAN physi- cal server coordinating interactions with the other three physical servers. All of the schools and departmental administrative offices are connected to the data center by fiber-optic cabling and treated as a single LAN rather than a Wide Area Network (WAN). RCN Communications, one of the town's cable provid- ers, furnishes the fiber-optic network, which is run on different fiber strands than RCN's cable TV Internet and voice traffic. Virtualization and Storage Various state and national regulations mandate that organizations in fields such as banking, healthcare, pharmaceutical, and government retain files for specified lengths of time. In addition to archiving information with cloud providers, organizations often use these providers as a lower-cost emergency backup in the event that their data is destroyed in a natural disaster, fire, or computer hacking incident. Enterprises can store up to a 1 petabyte (PB) of data in servers that are often as large as a refrigerator. These servers consume large amounts of energy and take up a great deal of space. Computers used for storage are now also able to take advantage of efficiencies attained by virtualization. Data stored in different database formats (for example, Microsoft SQL versus Oracle) can be stored on the same physical computer by using virtualization. Thus, the databases of various customers can be stored on the