scsi

2 Results

Dictionary

SCSI

(Small Computer System Interface) Pronounced "scuzzy." SCSI is a hardware interface for up to 15 peripheral devices attached to a single PCI board called a "SCSI host adapter" that plugs into...

Dictionary

Definition: SCSI

(Small Computer System Interface) Pronounced "scuzzy." SCSI is a hardware interface for up to 15 peripheral devices attached to a single PCI board called a "SCSI host adapter" that plugs into the motherboard. SCSI devices were popular in the mid-1980s and 1990s for two reasons. SCSI disks were known to be very robust and were used in servers and storage arrays. SCSI was also a way to add several peripheral devices to personal computers. Subsequently, IDE drives (ATA) became highly reliable, and USB allows 128 devices to plug in.

SCSI Is a Mini-LAN
SCSI uses a bus structure and functions like a mini-LAN connecting 16 devices, but the host adapter counts as one device. SCSI allows any two devices to communicate at one time (host to peripheral, peripheral to peripheral).

Host adapters are also available with two controllers that support up to 30 peripherals. Introduced in 1986 and originally developed by Shugart Associates (see SASI), SCSI is widely used in servers, mainframes and storage area networks (SANs).

The Daisy Chain
SCSI peripherals are daisy chained together. Each device has a second port used to connect the next device in line. An earlier advantage of using SCSI in a desktop PC was that a scanner and several drives (CD-Rs, Zip, hard disks, etc.) could be added to one SCSI cable chain. However, this became less important since the advent of the USB interface. For more details, see SCSI signaling.

RAID Was Originally SCSI
Until the late 1990s, SCSI hard disks were the only ones used in RAID configurations for improved performance or fault tolerance. Since the advent of IDE RAID controllers, SCSI and IDE have become more equalized, although SCSI continues to be the drive interface of choice in the server market. See SCSI signaling, SCSI connectors, RAID, SAS and SCSI switch.


SCSI

A SCSI Chain
The advantage of SCSI is that several peripherals can be daisy chained to one host adapter, using only one slot in the bus. For more details about SCSI specifications, signaling and connectors, see SCSI signaling and SCSI connectors.





Sponsored White Papers, Webcasts & Resources

  • Cutting corners with storage blades

    SCSI drives can cost as much as three to four times more than IDE ATA drives. Bill O'Brien looks at a new storage blade from StorageTek that cuts costs by eschewing SCSI for IDE hard disks.

    News items | November 4, 2002 12:00am PST

  • The building blocks of storage

    Think modular storage will make your data center more difficult to manage? Bill O'Brien says it won't--and it'll probably help you reduce costs, too.

    News items | August 2, 2002 12:00am PDT

Additional Results

  • Can FCoE replace iSCSI?

    Can Fiber Channel over Ethernet become your storage networking standard?

    Blog posts | July 30, 2010 12:59pm PDT

  • StarWind Software Take Two

    Users respond to StarWind Post

    Blog posts | February 24, 2010 3:30am PST

  • Star Wind Software claims "Zero to SAN in 30 Minutes"

    StarWind iSCSI SAN - can it live up to the claims?

    Blog posts | February 22, 2010 3:00am PST

  • HP Acquires LeftHand Networks, Virtualized iSCSI Storage Vendor

    Today, HP announced the intention to acquire iSCSI storage vendor LeftHand Networks for $360 Million in cash. LeftHand makes virtualized storage array software that can turn just about any server,...

    Blog posts | October 2, 2008 7:28am PDT

  • 6 Gbit drives coming

    Chip vendor PMC-Sierra and Seagate announced that they've . . . achieved interoperability between PMC-Sierra’s end-to-end 6Gb/s SAS chipset and Seagate’s early development 6Gb/s SAS Hard...

    Blog posts | May 13, 2008 11:12pm PDT

  • Waiting for Leopard's iSCSI support

    While waiting for Apple to fold iSCSI initiator and target support into Leopard's client and server versions, respectively, third-party developers offer a range of solutions.

    Blog posts | December 10, 2007 5:52pm PST

  • Dell to buy storage company for $1.4 billion

    With its planned acquisition of EqualLogic, the PC maker intends to make itself a force in what it calls "the iSCSI revolution."

    News items | November 5, 2007 7:25am PST

  • Red Hat, NetApp work for iSCSI Linux support

    Red Hat Enterprise Linux update 4 will include iSCSI support in cooperation with the storage system maker.

    News items | December 6, 2004 10:49pm PST

  • Windows hooks up with iSCSI

    Microsoft releases a driver for the emerging iSCSI specification that lets its operating system share storage gear using Ethernet networks.

    News items | June 30, 2003 6:57pm PDT

  • SCSI prototypes square off

    Three tech allies demonstrate a new storage technology that they believe will keep a venerable hard drive standard safe from extinction.

    News items | June 21, 2003 12:20am PDT

  • iSCSI receives industry approval

    A key standards body gives its blessing for iSCSI, a new technology that allows storage area networks to be built using existing Ethernet networking.

    News items | February 12, 2003 11:49pm PST

  • Cutting corners with storage blades

    SCSI drives can cost as much as three to four times more than IDE ATA drives. Bill O'Brien looks at a new storage blade from StorageTek that cuts costs by eschewing SCSI for IDE hard disks.

    News items | November 4, 2002 12:00am PST

  • New storage tech "iSCSI" moves closer

    A technology that promises to bridge the worlds of data storage and networking has passed a key point on its path to becoming a usable standard.

    News items | September 6, 2002 12:15pm PDT

  • The building blocks of storage

    Think modular storage will make your data center more difficult to manage? Bill O'Brien says it won't--and it'll probably help you reduce costs, too.

    News items | August 2, 2002 12:00am PDT

  • IP storage--inspiration or insanity?

    Indiana Jones were alive today, he'd eschew dull old archaeology for the thrills of distributed terabyte storage. At least, that's what the manufacturers would have us believe. But basing today's...

    News items | July 10, 2002 12:00am PDT

  • Standards group to promote faster SCSI

    An effort to create a higher-speed version of the SCSI technology has been embraced by the standards group in charge of the interface used to connect fast hard drives. The SCSI Trade Association...

    News items | February 5, 2002 8:00pm PST

  • iSCSI vs. Fibre Channel

    Many IT professionals like the concept of storage area networks (SAN), but they're resistant to Fibre Channel (FC), the networking technology that brings nearly all SANs to life. As a protocol...

    News items | July 24, 2001 12:00am PDT

ie8 fix

The best of ZDNet, delivered

ZDNet Newsletters

Get the best of ZDNet delivered straight to your inbox

Facebook Activity

ie8 fix