Network Direct Attached Storage (NDAS) is a proprietary

storage area network A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from se ...

system, originally marketed by the company Ximeta, for connecting external digital storage devices such as hard-disks, flash memory and tape drives via the

Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in ...

family of

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections ar ...

s. Unlike other more common forms of networked storage, NDAS does not use

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

to communicate over the network. Instead a Lean Packet Exchange (LPX) protocol is used. NDAS also supports some limited

RAID Raid, RAID or Raids may refer to: Attack * Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground * Corporate raid, a type of hostile takeover in business * Panty raid, a prankish raid by male colleg ...

functions such as aggregation and mirroring.

History

In 2001, Han-gyoo Kim of Korea and Zhe Khi Pak of Russia applied for a US patent on a "network-attached disk". By 2002 the first NetDisk (up to 80 GB) was marketed as a low cost alternative to full computer based network storage options. The Ximeta company was founded in 2003. In 2004 Kim applied for a patent to allow multiple clients write access to the shared block storage device. By 2006, sizes up to 500 GB were supported. In 2008 an NDAS device called "ShareDisk Gigabit" created by Co-World Cs in Germany briefly claimed the title of world's fastest network storage device. In 2011 IOCELL Networks announced ownership of the NDAS system and NetDisk patents. The following year, IOCELL revived

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...

client support for NDAS—which Ximeta had "temporarily suspended" in September 2009—by releasing the drivers under the terms of the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end user In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ulti ...

(GPL) as the open-source "ndas4linux" project.

Benefits

* Hardware is typically easy to set up and use, particularly when a unit is purchased with a disk installed. * The disk drive can be used via multiple interfaces (typically eSATA, USB or Ethernet) though not concurrently: USB and eSATA allow access by only one host. * The disks do not require special formatting so they can be treated as external disks on a wide variety of computers. * Performance (speed vs. cost) is claimed to be better than similarly priced storage devices. * Devices are isolated from external network discovery since the protocol is not visible through a router.

Drawbacks

* The LPX Protocol is not routable, thus limiting access to one

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...

. * Some firewall programs block the LPX protocol by default. It uses EtherType value 0x88AD. * Drivers required to operate NDAS devices over a network are not shipped with operating systems. The devices are usually accompanied with client driver software for Microsoft Windows operating systems. * Drivers for

-based operating systems (

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading on ...

s such as

Fedora A fedora () is a hat with a soft brim and indented crown.Kilgour, Ruth Edwards (1958). ''A Pageant of Hats Ancient and Modern''. R. M. McBride Company. It is typically creased lengthwise down the crown and "pinched" near the front on both sides ...

, Ubuntu or

Debian Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of De ...

) were originally available only from the manufacturer.

References

{{Reflist Storage area networks Network protocols Ethernet

History

Benefits

Drawbacks

See also

References