Network-attached storage
Encyclopedia : N : NE : NET : Network-attached storage
Network-attached storage (commonly abbreviated to NAS) systems are generally computing-storage devices that can be accessed over a computer network (usually TCP/IP), rather than directly being connected to the computer (via a computer bus such as SCSI). This enables multiple computers to share the same storage space at once, which minimizes overhead by centrally managing hard disks. NAS systems usually contain one or more hard disks, often arranged into logical, redundant storage containers or RAID arrays.
The protocol used with NAS is a file based protocol such as NFS, Samba or Microsoft's Common Internet File System (CIFS). In reality, there is a miniature operating system on the device such as DART on EMC's Celerra devices or Data ONTAP on NetApp NAS devices.
A storage area network (SAN) is very similar, except it uses a block-based protocol and generally runs over an independent, specialized storage network.
NAS devices become logical file system storage for a local area network. Thus the performance of NAS devices depends heavily on cached memory (the equivalent of RAM) and network interface overhead (the speed of the router and network cards). The benefit is that the device can become a giant neighborhood hard drive for a whole building. The disadvantage is that any constrictions in the local network will slow down the resulting access time.
NAS was developed to address problems with Direct Attached Storage, which included the effort required to administer and maintain "server farms", and the lack of scalability, reliability, availability, and performance. They can deliver significant ease of use, provide heterogeneous data sharing and enable organizations to automate and simplify their data management.
In addition, the price of NAS appliances has plummeted in recent years, offering flexible network based storage to the home consumer for little more than the cost of a regular USB or Firewire external hard disk. Many of these home consumer devices are built around Processors running an Embedded Linux Operating system.
NAS applications
NAS allows multiple server access through a file-based protocol. This allows administrators to implement simple and low cost load-balancing and fault-tolerant systems.For example:
- Corporate e-mail system with multiple, load-balanced webmail servers
- Load-balanced web servers access the same contents from NAS storage
Enterprise NAS Vendors
Appliance-based NAS was pioneered by Auspex, based on the success of file servers from Novell, IBM, Microsoft, and Sun Microsystems.
Current vendors include:
NAS for SOHO (Small Office/Home Office)
NAS are becoming popular for Home and Small Business use. Today, you can buy simple NAS-solutions like the popular Linksys NSLU-2. Infrant Technologies [ReadyNAS] is a newcomer, but offers a rich feature set including RAID-5 and the ability to add the drives yourself. These small-footprint appliances excel at low-power, low-noise, and low-cost. Free NAS servers are available to download from the internet, like [FreeNas], NASLite or [Openfiler]. They are easy to configure via Webinterface and run on even the slowest computers.List of External NAS Devices under $1000
| Class | Company | Product | LAN | WLAN | SMB | FTP | NFS | AFP | Hard Drive Computer bus | |
| NAS | Spintronics | LANDISK | Fast Eth | - | X | X | - | - | IDE | |
| NAS | V-Gear | Landisk | Fast Eth | - | X | X | - | - | IDE | |
| NAS | CLAXAN | CL-NAS110 | Fast Eth | - | - | - | - | - | IDE | |
| DSL/Cable Access Router + NAS | CLAXAN | CL-SA110 | Fast Eth | - | - | - | - | - | IDE | |
| DSL/Cable Access Router + NAS | CLAXAN | CL-SA113 | Fast Eth | - | - | - | - | - | IDE | |
| NAS | Intellinet | NAS, 522991 | Fast Eth | - | X | X | X | X | IDE | |
| DSL/Cable Access Router + NAS | Intellinet | SOHO SERVER | Fast Eth | - | X | X | X | X | IDE | |
| NDAS | Ximeta | NetDisk | Fast Eth | - | - | - | - | - | IDE | |
| NDAS | Ximeta | NetDisk Office | Fast Eth | - | - | - | - | - | IDE | |
| NDAS | Ximeta | NetDisk Office Wireless | Fast Eth | 802.11b/g | - | - | - | - | IDE | |
| NDAS | Ximeta | NetDisk Mini | Fast Eth | - | - | - | - | - | IDE | |
| NDAS | Ximeta | NetDisk Enclosure | Fast Eth | - | - | - | - | - | IDE | |
| NAS | Iomega | Network Hard Drive | Fast Eth | - | - | - | - | - | IDE | |
| NAS | Iomega | NAS 100d | Fast Eth | 802.11b/g | X | X | X | X | IDE | |
| NAS | LaCie | Ethernet Disk | Fast Eth | - | - | - | - | - | IDE | |
| NAS | LaCie | Ethernet Disk mini | Fast Eth | - | X | X | X | IDE, USB2.0 x 1 | ||
| NAS | Asus | WL-HDD 2.5 | Fast Eth | 802.11b/g | - | - | - | - | IDE 2.5in | |
| NAS-USBHD+Router | Asus | WL-500B | Fast Eth | 802.11b | - | - | - | - | USB1.1 | |
| NAS-USBHD+Router | Asus | WL-500G | Fast Eth | 802.11b/g | - | - | - | - | USB1.1 | |
| NAS-USBHD+Router | Asus | WL-500G deluxe | Fast Eth | 802.11b/g | - | X | USB 2.0x2 | |||
| NAS, NAS-USBHD | D-Link | DSM-602H, DSM-604H | Fast Eth | - | X | - | - | - | USB1.1 | |
| NAS, NAS-USBHD | D-Link | DSM-622H, DSM-624H | Fast Eth | 802.11b/g | X | - | - | - | USB1.1 | |
| NAS-USBHD | D-Link | DNS-120 | Fast Eth | - | X | X | - | - | 2x USB 2.0 | |
| NAS-USBHD | Allnet | ALL6100 | Fast Eth | - | X | - | - | - | USB2.0 x 2 | |
| NAS | Allnet | ALL6200 | Fast Eth | - | X | X | - | - | IDE | |
| NAS | Allnet | ALL6400 | Giga Eth (2x) | - | X | - | - | - | 4x S-ATA hot-swappable, RAID | |
| NAS | Flepo | F6200 | Fast Eth | - | X | X | - | - | IDE | |
| NAS | Longshine | LCS-8200 | Fast Eth | - | X | X | - | - | IDE | |
| NAS-USBHD | Linksys | NSLU2 | Fast Eth | - | X | - | - | - | USB2.0 x 2 | |
| NAS | Linksys | Etherfast EFG120, EFG250 | Giga Eth | - | X | X | - | - | IDE | |
| NAS-USBHD | Ovislink | MU-5000FS | Fast Eth | - | X | X | - | - | USB2.0 x 2 | |
| NAS | Ovislink | MU-9000VPN | Fast Eth | - | - | X | - | - | USB2.0 x 4 | |
| NAS | Ovislink | WMU-9000VPN | Fast Eth | 802.11b/g | - | X | - | - | USB2.0 x 4 | |
| NAS | Buffalo | LinkStation HD-H120LAN | Fast Eth | - | X | X | - | - | IDE, USB2.0 x 2 | |
| NAS | Buffalo | LinkStation HD-HG120LAN | Giga Eth | 802.11b/g | X | X | - | - | IDE, USB2.0 x 2 | |
| NAS | Buffalo | Tera Station | Giga Eth | - | X | X | - | - | IDE | |
| NAS | Melco | Kuro Box | Fast Eth | - | X | X | X | - | IDE, USB2.0 | |
| NAS | Melco | Kuro Box HG | Giga Eth | - | X | X | X | - | IDE, USB2.0 | |
| NAS-USBHD+Router | Netgear | WGT634U | Fast Eth | - | X | X | - | - | USB2.0 | |
| NAS | Synology | DS-101 Diskstation | Fast Eth | - | X | X | - | X | IDE, USB2.0 x 2 | |
| NAS | Synology | DS-101 G+ Diskstation | Giga Eth | - | X | X | - | X | S-ATA (int and ext), USB2.0 x 2 | |
| NAS | Snap Appliance | Snap Server 1100 | Fast Eth | - | - | - | - | - | IDE | |
| DSL/Cable Access Router + NAS | Tritton | TRI-ASA1120, TRI-ASA1200 | Fast Eth | - | X | - | - | - | IDE | |
| DSL/Cable Access Router + NAS | Tritton | TRI-ASA2120, TRI-ASA2200 | Fast Eth | - | X | - | - | - | IDE | |
| NAS | Tritton | TRI-NAS080, 120, 200 | Fast Eth | - | X | - | - | - | IDE | |
| NAS | Tritton | TRI-WHD1120, 1200 | Fast Eth | 802.11b/g | X | - | - | - | IDE | |
| DSL/Cable Access Router + NAS | IOGEAR | BOSS | Fast Eth | - | - | - | - | - | IDE | |
| NAS | SERCOMM | interNAS/Compact-ND53 | Fast Eth | - | X | - | - | - | IDE | |
| NAS | SERCOMM | interNAS-GS53 | Fast Eth | - | X | - | - | - | IDE | |
| NAS | SERCOMM | interNAS/RAID-NR53 | Fast Eth | - | X | - | - | - | IDE | |
| NAS+Server | teac | Vendotto NS-40 Basic | Fast Eth | - | - | - | - | - | IDE | |
| NAS+Server | teac | Vendotto | Fast Eth | - | - | - | - | - | IDE | |
| NAS+Server | teac | Vendotto WALL | Fast Eth | - | - | - | - | - | IDE | |
| NAS | SMC | SMC7208SBR | Fast Eth | - | X | - | - | AT | IDE | |
| NAS-USBHD+Router | U.S. Robotics | USR8200 | Fast Eth | - | X | X | - | - | USB2.0 x 2, IEEE1394 | |
| NAS | Maxtor | Shared Storage | Fast Eth | - | X | ? | ? | ? | IDE, USB2.0 x 2 | |
| NAS-USBHD+WLAN-Router | T-Com | Sinus 154 DSL SE | Fast Eth | 802.11b/g | X | - | - | - | USB 1.1 | |
| NAS | Intradisk | Server | Fast Eth | - | X | X | X | - | IDE | |
| NAS + Server | Intradisk | Profi | 2x Fast Eth | 802.11b/g | X | X | X | - | IDE | |
| NAS | Thecus | N4100 | Giga Eth (2X) | optional | X | X | - | X | 4x S-ATA hot-swappable, RAID | |
| NAS | Thecus | N2100 | Giga Eth (2X) | optional | X | X | - | X | 2x S-ATA, RAID | |
| NAS | Thecus | N5200 | Giga Eth (2X) | optional | X | X | X | X | 5x S-ATA hot-swappable, RAID | |
| NAS | Thecus | N5200 RouStor | Giga Eth (5X) | optional | X | X | X | X | 5x S-ATA hot-swappable, RAID | |
External links
- [FreeNas]
- [FreeNas(Chinese)]
- [NASLite]
- [Openfiler]
- [Darma] (Please note that work on this product has been suspended)
See also
- Secure Shell Filesystem - locally mount a remote directory on a server using only a secure shell login.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.