by: William Hauselberg
A Storage Area Network (SAN) is a collection of storage devices that are
tied together via a high-speed network to create one large storage
resource that can be accessed by multiple servers. SANs are typically
used to store, share and access enterprise data in a more secure and
efficient manner compared to traditional dedicated storage models. With
dedicated storage, each server is equipped with, and uses an attached
storage capability. A SAN meanwhile basically acts as a common, shared
storage resource for multiple servers. The storage devices in a SAN can
include disk arrays, tapes and optical jukeboxes all of which can be
accessed and shared by all of the attached servers.
How a Storage Area Network Works
In a storage area network, the pooled storage resources and the servers
that access this storage are separated by a layer of management
software. The software allows IT administrators to centralize and manage
multiple storage resources as if it were one consolidated resource.
Because of the software, each of the servers sees just one storage
device, while each of the storage devices in the SAN sees just one
server. Data can be moved at will to any of the devices on a SAN.
Factors Driving SAN Adoption
A variety of factors have been driving enterprise adoption of SAN
architectures over the past few years. One of the biggest factors has
been increased cost-efficiencies. Storage area networks allow companies
to optimize the utilization of their storage resources. With an attached
storage disk, any extra storage capacity on that disk would remain
unused because no other server could use it. With a SAN on the other
hand, all memory resources are pooled, resulting in better usage of
existing capacity. Since SAN�s allow data to be moved freely,
enterprises can also move old and outdated data to inexpensive storage
devices while freeing up the more costly devices for more important
data.
Storage area networks make it easier for companies to expand their
storage capacity, add resources on the fly, allot additional resources
to an application, and maintain systems far more easily than traditional
storage technologies. In addition, SANs allow companies to swap out a
disk or tape-drive more easily and enable faster data replication.
Importantly, SAN architectures allow storage devices from multiple
vendors to be tied together into a common shared storage pool. Another
advantage of SAN architectures is that they allow the storage network to
be located at long distances away from the server hardware, thereby
enabling greater disaster recoverability.
SAN Security a Big Concern
Despite such benefits, there are some caveats associated with the
implementation of SAN architectures. Storage area network security is by
far the biggest issue that companies need to do deal with when moving
to a SAN storage model. With a SAN, companies are literally putting all
of their most important data in one central resource. As a result the
need for security controls such as firewalls, intrusion detection
systems, SAN encryption and network monitoring are greatly heightened.
