Storage Area Networks

d for storage devices is growing by leaps andThese devices are assigned an IP address and then
bounds. In addition there are a number of optionscan be accessed by clients via a server that acts as
available depending on specific storage requirements.a gateway to the data or in some cases allows the
There are numerous options available with SAN. Thedevice to be accessed directly by the clients without
two most popular variants are Fibre channel (FC) andany intermediary. Easy manageability is a important
Internet Protocol (IP). In a FC SAN the disc arraysfeature of NAS. It is focused on simple file serving
are connected using fibre channel connections. An FCneeds. NAS and SAN are complimentary to each
switch acts as the central point of control for dataother. The trend is towards hybrid solutions. SAN can
flowing through the SAN. Hence, FC or IP dependsbe used as a back end and NAS as the front end ie
upon the application. If the data is critical, Fibrehaving a NAS header in a SAN environment.
Channel is a better option. A low cost SAN is anLarge organizations with enterprise networks and a
integrated package that includes an FC switch,wide geographical spread are opting for SAN
high-performance software and disc storage that canwhereas small and medium businesses find NAS a
be hooked up to two servers.better option. In SAN there is a movement towards
An IP SAN uses the internet small Computer SystemIP because one can use the same protocol as the
Interface iSCSI protocol and Gigabit Ethernet overnetwork leading to a lesser cost of implementation.
Cat 6 cabling to hook up disc arrays over aGrowth in chassis —based SAN switches is
Transmission control protocol / Internet protocolfaster than in the fabric switch segment because of
(TCP/IP) network. These SANs provide native-levelSAN and storage consolidation and linking of first
block access and data transfer and are similar in thisgeneration SAN islands. Also ,the need to implement
respect to traditional FC SANs. Essentially a customerSAN extension solutions for data replication and
data centre requires various transport technologiesbusiness continuity is driving the need for intelligent
that enable long distance connectivity in a costmultilayer SAN switches and related products.
effective manner. Fiber Channel is better for highUltimately the choice between San or NAS depends
speed connectivity and applications such as ERP andon a number of factors. The cost of implementation,
databases. For a small organization IP SAN wouldease of maintenance, fault tolerance and security are
suffice. A judicious mix of both IP and Fiber Channelsome of the aspects which have to be considered
is required to balance cost and efficiency of storagewhile adapting a particular storage system. It is also
systems and devices.possible to have a hybrid system with both SAN and
NAS and SANNAS being used simultaneously. . One fit all is no
NAS is a data storage mechanism where the storagelonger feasible and the trend is towards a mixed bag
devices are connected directly to the network.of options.