Network Attached Storage (NAS)

A network-attached storage device acts as a server that is committed to file sharing. NAS doesn’t offer any of the activities that a server in a server-centric system typically provides such as e-mail, authentication or file management. NAS permits more hard disk storage space to be added to a network that already uses servers without shutting them down for maintenance and upgrades. Storage is not an integral part with a NAS device of the server. Instead in this storage centric design, the server still grips all of the processing of data but a NAS device transfers the data to the user. A NAS device does not require locating within the server but can exist anywhere in a LAN and can be made up of multiple networked NAS devices.

By creating systems designed specifically for data storage NAS dominates the traditional file server approach. NAS designs start with the bare-bones components require to provide support for file transfers and add features "from the bottom up." NAS use to follows a client/server structure like traditional file servers. A single hardware device is known as NAS box or NAS head which act as the interface between the NAS and network clients. These NAS devices don’t require monitor, keyboard or mouse. They execute on embedded operating system rather than a full-featured NOS. One or more disk drives can be connected to many NAS systems to improve total capacity. Clients always attach to the NAS head rather than to the individual storage devices.

NAS Protocols
Communication with a NAS head is performed over TCP/IP. Clients use any of several higher-level protocols based on top of TCP/IP.
The two application protocols related with NAS are Sun Network File System (NFS) and Common Internet File System (CIFS). Both NFS and CIFS work in client/server way. For sharing files between UNIX systems over a LAN, NFS was developed.
The CIFS was called as Server Message Block (SMB). In DOS to support file sharing SMB was developed by IBM and Microsoft. As the protocol used in Windows the name changed to CIFS. Today this same protocol presents in UNIX systems within Samba package.
Many NAS systems provide support to Hypertext Transfer Protocol (HTTP). Clients use to download files in their Web browser from a NAS which provide supports to HTTP. For Web-based administrative user interfaces NAS systems utilize HTTP as an access protocol.

NAS Solutions for Today's Business Issues
It considers that the demands of Internet service providers, application service providers and dotcoms for reliable, cost-effective systems will help drive the creation of NAS solutions.

1) Decreased IT Staff Costs
On one end, businesses allow extreme amounts of data and try hard to manipulate it for use in real time. On other end, IT professionals with their current infrastructures, jumble to accommodate the exponentially rising data burden. General-purpose servers need large amounts of skilled personnel time to solve storage and file access challenges.
In contrast, a NAS device needs little IT staff time and effort. Management is done with the help of graphical user interface (GUI) in a Web browser which allows NAS access from anywhere on the network. Since a NAS filer is configured to support specific file-serving requires the administration is cut down and this ease of use results in fewer operator errors. More capacity can be arranged per administrator with NAS than with general-purpose server storage activity so the total cost of ownership is lower.

2) Scale Fast without Downtime
Dotcoms and other rapidly scaling companies try to ensure their IT infrastructures keep pace with their dynamic business realities. Building on the structure of general server or servers may be needed in some business areas. But loading these servers with increasing storage needs can be ineffective and run counter to accelerated business practices. As it provides capacity to general-purpose server, it'll face downtime. When the system is brings down to increase its storage capacity then business applications will be unavailable to the user.

NAS with expanding storage is simple and no intrusive. More modified NAS devices can increase storage capacity on-the-fly, reducing the need to add another node on the network. This means users access what and when they need it.

3) Reliefs for Your Server
A NAS filer provides help by freeing tedious and bandwidth-consuming file serving tasks from server. This permits server to use its power to process data with improved availability and performance.

4) Multi-OS Connectivity and Data-Sharing
A NAS device offers service to the operating system camps: NFS (UNIX) and CIFS (Microsoft Windows). One of the strengths of NAS is its capacity to provide support to these protocols and permit cross-platform data sharing. This is progressively more important attribute as the business usage of data-intensive application files such as audio, video, and photography becomes more common.

5) Leveraging Existing Infrastructure
NAS can be arranged on network anywhere as per requirement. It also can be incorporated with larger management tools like Microsoft Management Console and HP Open view allow to maximize use of these products. NAS doesn’t need costly network operating system licenses. NAS can help to understand the intention of centralization by allowing storage in a remote office and managing it via the Web-based GUI from anywhere on network. It provides higher performance from existing infrastructure at the remote office.

Conclusion
NAS filers provide service to any business or technology workgroup from software design to CAD, to service providers/dotcoms, to engineering which needs low cost, scalability and high-performance in a file server. NAS work with SAN environment for handling network files. Unexceptional and helpful NAS meld with existing infrastructure and facilitate data sharing over heterogeneous operating environments.