Storage Area Networks
A Storage Area Network (SAN) provides high-performance, highly-available disk storage that serves as a centralized repository for an organization’s mission critical data. A SAN has many advantages over traditional server-based storage including increased flexibility in allocating storage to servers, the ability to do automatic prescheduled data "snapsnots", improved scalability, improved fault tolerance and improved performance. While all these features are important, the "snapshot" feature is perhaps the most beneficial as it provides the ability to easily and instantly restore data from a past point in time.
A SAN is also a key component in many server and desktop virtualization solutions. In this scenario, the SAN provides the shared storage necessary to allow the virtual servers or virtual desktops to seamlessly transition between host servers with no interruption in service. This provides for increased availability and better overall performance.
Storage Area Networks also play a key role in the disaster recovery plans for many organizations. Most SAN solutions provide the ability to replicate data volumes from the main data center to an offsite data center. This approach is typically much more reliable than the legacy method of using some type of server-based replication. SAN Replication is especially important in a virtualized environment as it allows the virtual servers, which exist as data files on the SAN, to be automatically replicated on a pre-determined schedule to an offsite facility. Having these data files automatically updated at the remote site on an hourly, daily or weekly basis allows the virtual servers to be easily restarted from the offsite facility with little to no reconfiguration in the event of a disaster. This is extremely important for those organizations who need to maximize application availability while minimizing cost.