There is no doubt that the demand for storage has been increasing exponentially. Business communications have evolved from simple text to elaborate graphics-heavy documents and fancy graphics-based presentations.
iCommerce, eCommerce, and other ever-increasing eBusiness solutions that require corporate data centers to provide information in various formats have all contributed to the explosion in demand for storage capacity. Enterprise class businesses are deploying huge RAID devices that are Terabytes (TB) in size.
NAS is a abbreviation of Network attached storage.A term used to refer to storage element that connect to a network and provide file access services to computer systems. Abbreviated NAS. A NAS Storage Element consists of an engine, which implements the file services, and one or more devices, on which data is stored. NAS elements may be attached to any type of network. When attached to SANs, NAS elements may be considered to be members of the SAS class of storage elements.
A class of systems that provide file services to host computers. A host system that uses network-attached storage uses a file system device driver to access data using file access protocols such as NFS or CIFS. NAS systems interpret these commands and perform the internal file and device I/O operations necessary to execute them.
Network-attached storage (NAS) is a concept of shared storage on a network. It communicates using Network File System (NFS) for UNIX® environments, Common Internet File System (CIFS) for Microsoft Windows environments, FTP, http, and other networking protocols. NAS brings platform independence and increased performance to a network, as if it were an attached appliance. A NAS device is typically a dedicated, high-performance, high-speed communicating, single-purpose machine or component. NAS devices are optimized to stand-alone and serve specific storage needs with their own operating systems and integrated hardware and software. Think of them as types of plug-and-play appliances, except with the purpose of serving your storage requirements. The systems are simplified to address specific needs as quickly as possible-in real time. NAS devices are well suited to serve networks that have a mix of clients, servers, and operations and may handle such tasks as Web cache and proxy, firewall, audio-video streaming, tape backup, and data storage with file serving. These highly optimized servers enable file and data sharing among different types of clients. It also defines NAS benefits with respect to storage area networks (SANs).
NAS devices known as filers focus all of their processing power solely on file service and file storage. As integrated storage devices, filers are optimized for use as dedicated file servers. They are attached directly to a network, usually to a LAN, to provide file-level access to data. Filers help you keep administrative costs down because they are easy to set up and manage, and they are platform-independent. NAS filers can be located anywhere on a network, so you have the freedom to place them close to where their storage services are needed. One of the chief benefits of filers is that they relieve your more expensive general-purpose servers of many file management operations. General-purpose servers often get bogged down with CPU-intensive activities, and thus can't handle file management tasks as efficiently as filers. NAS filers not only improve file-serving performance but also leave your general-purpose servers with more bandwidth to handle critical business operations.
The emergence storage networking provides a very high performance networks. The majour components of the storage networking are SAN and NAS. These components performs various functions as follows