Network attached storage

Description

Waiter NAS has the role to be accessible since waiters customer through the network to store data there. The management centralized in the form of files has several advantages:

to facilitate the management of the safeguards of the data of a network
reasonable price of the discs great capacities compared to the purchase of discs in great number on each waiter of the network
access by several waiters customers to same the data stored on the NAS
reduction of time of administration of the waiters customers in management of disk space

The principal data-processing component of this type of waiter is the Hard drive. The interface SCSI, IDE, SAS, SATA or Fiber Chanel used is selected according to required the cost ratio/performance. Technology RAID is employed to make safe the data stored against the failure of one or more hard drives.

The NAS can be integrated or be the entrance point of a SAN.

Market of the NAS

The price of systems NAS fell much these last years (approximately 300 € for 500 Go in 2007) and makes it possible to install such systems in small companies, even of the private individuals, for hardly expensive than of the traditional storage systems. These small NAS ensure however of weak performances. The prices of the large NAS of company remain in the neighborhoods of 15000€ for the line entry and can reach several hundreds of thousands of euros. There exists also an intermediate range to a few thousands of euros where a special version of Windows sold only in OEM dominates: Windows Storage Server 2003 and some alternatives under Linux or of the systems connected like GuardianOS for range NAS SnapServer d' Adaptec.

has term used to refer to storage elements that connect to has Network and provide File access services to Computer systems. With NAS Storage Element consists off year engine, which implements the file services, and one gold more devices, one which dated is stored. NAS elements may standard Be attached to any off Network. When attached to SAN S, NAS elements may Be considered to Be members off the Server Attached Storage (SAS) class off storage elements.

has class off systems that provide file services to host computers. With host system that use network attached storage use has file system device driver to access dated using File access protocols such ace NFS gold CIFS. NAS systems interpret thesis commands and perform the internal file and device I/O operations necessary to carries out them.

NAS systems are generally computing-storage devices that edge Be accessed over has Computer network (usually TCP/IP), rather than directly being connected to the computer (via Computer drunk such ace SCSI has). Multiple This enables computers to share the same storage space At ounce, which minimizes overhead by centrally managing Hardware disk S. NAS systems usually contain one gold more Hardware disk S, often arranged into logical, redundant storage containers gold RAID arrays.

The protocol used with NAS has file based protocol such ace NFS, Samba gold Microsoft' S Common Internet Spins System (CIFS). In reality, there has miniature Operating system one the device such ace DART one EMC 'S Celerra devices gold Data ONTAP one NetApp NAS devices.

With Storage area network (SAN) is very similar, except it use has block-based protocol and generally runs over year independent, specialized storage network.

NAS devices become logical File system storage for has Local area network. Thus the performance off NAS devices depend heavily one cached memory (the equivalent off RAM) and network interface overhead (the speed off the router and Network card S). The benefit is that the device edge become has giant neighborhood hardware drive for has whole building. The local disadvantage is that any constrictions in the network will slow fox trot down the resulting access time. -->

Applications of the NAS

Waiter NAS authorizes accesses coming from multiple waiters based on the files. This authorizes the administrators to be established easily and with lower costs of the systems of Répartition of load and Fault-tolerance.

For example:

System of Email with multiples waiter S and Distribution of load
Web servers with Distribution of load reaching the same contents of a storage NAS

Safety

The NAS increases the data security present on this one by:

the system RAID authorizing the failure of disc without loss of data
the simplicity of the operating system as well as applications present reducing the number of exploitable security breaches

Waiters NAS marketed by security companies of software adds to the safety of the system the principle of the Sécurité by the darkness which appeared false.

Editor NAS

The NAS was conceived by Auspex Systems based on the success of the file servers of Novell, IBM and Microsoft. The generalization of its marketing must with the launch of the Network Appliance Filer and of its low costs in comparison with the system Fiber Chanel SAN. Recently, of new companies like Coraid, ONStor, ALLNET the USA and BlueArc combined the facility of management of the NAS with the performances and the potential of increase in capacity of SAN.

See too

the NDAS: Direct Network Attached Storage
the SAN: Storage Area Network (not to confuse SAN and NAS)
NASLite, a Linux distribution intended to transform a computer into file server.

External bonds

FreeNAS : free software, based on FreeBSD, which, like NASLite, aims at transforming an old computer into NAS.

Random links: