Etherdrive
Encyclopedia
Storage area network
A storage area network is a dedicated network that provides access to consolidated, block level data storage. SANs are primarily used to make storage devices, such as disk arrays, tape libraries, and optical jukeboxes, accessible to servers so that the devices appear like locally attached devices...
devices based upon the ATA over Ethernet
ATA over Ethernet
ATA over Ethernet is a network protocol developed by the Brantley Coile Company, designed for simple, high-performance access of SATA storage devices over Ethernet networks. It is used to build storage area networks with low-cost, standard technologies.- Protocol description :AoE runs on layer 2...
(AoE) protocol. EtherDrive is a registered trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...
of Coraid, Inc.
Coraid, Inc.
Coraid, Inc. is a storage vendor that provides Ethernet SAN solutions, headquartered in Redwood City, California.- Company history :The company was founded by Brantley Coile, who previously invented the Cisco PIX firewall and Cisco LocalDirector products....
. EtherDrive is an invented word, owned and used as a trademark by Coraid since 2002 and registered with the United States Patent and Trademark Office in 2004. The word was invented by Brantley W. Coile as a portmanteau of the words Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
and disk drive.
History
The first commercial transaction involving interstate commerce of an EtherDrive branded product was to Geoff CollyerGeoff Collyer
Geoff Collyer is a Canadian computer scientist. He is the senior author of C News, a protocol-neutral news transport, and the designer of NOV, the News Overview database used by all modern newsreaders....
. Some of the first EtherDrive products were embedded Z80 based boards that acted as AoE converters (see Figure 1). These boards were attached like a daughterboard to PATA disk drives mounted and connected to a backplane that provided only power and an RJ-45 jack. These original PATA blades were aligned in a single row per shelf and addressed by over Ethernet with a shelf:slot address. The slot component eventually became referred to as a LUN.
Today, EtherDrive devices provide RAID 0, 1, 5, 10, and JBOD. These use AoE to talk to the initiator but provide a hardware RAID close to disk. The device also provides a block scrubbing mechanism called RAIDShield that systematically checks every block on every disk for potential failures. When a bad block is encountered, the block is reconstructed from parity and written to another part of the disk.
EtherDrives have been used as storage for high altitude atmospheric research and aeronautical applications. Combined with SSD disks the technology is an easy solution to data acquisition in the embedded space. Since it uses AoE the device is presented to the host OS as block storage, and thus the EtherDrive requires minimum overhead from the host system.