Set of computer and peripheral connection standards
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Small Computer System Interface (SCSI, /ˈskʌzi/SKUZ-ee)[1] is a set of standards for physically connecting and transferring data between computers and peripheral devices, best known for its use with storage devices such as hard disk drives. SCSI was introduced in the 1980s and has seen widespread use on servers and high-end workstations, with new SCSI standards being published as recently as SAS-4 in 2017.
The SCSI standards define commands, protocols, electrical, optical and logical interfaces. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. The initial Parallel SCSI was most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives, although not all controllers can handle all devices.
The ancestral SCSI standard, X3.131-1986, generally referred to as SCSI-1, was published by the X3T9 technical committee of the American National Standards Institute (ANSI) in 1986. SCSI-2 was published in August 1990 as X3.T9.2/86-109, with further revisions in 1994 and subsequent adoption of a multitude of interfaces. Further refinements have resulted in improvements in performance and support for ever-increasing data storage capacity.[2]
Small Computer System Interface (SCSI, /ˈskʌzi/ SKUZ-ee) is a set of standards for physically connecting and transferring data between computers and peripheral...
Parallel SCSI (formally, SCSI Parallel Interface, or SPI) is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus;...
Interface or iSCSI (/aɪˈskʌzi/ eye-SKUZ-ee) is an Internet Protocol-based storage networking standard for linking data storage facilities. iSCSI provides block-level...
A SCSI connector (/ˈskʌzi/ SKUZ-ee) is used to connect computer parts that communicate with each other via the SCSI standard. Generally, two connectors...
In computing, Serial Attached SCSI (SAS) is a point-to-point serial protocol that moves data to and from computer-storage devices such as hard disk drives...
In SCSI computer storage, computers and storage devices use a client-server model of communication. The computer is a client which requests the storage...
OS; the sole exception, the Workgroup Server 95—a Quadra 950 with an added SCSI controller that shipped with A/UX—was also capable of running Mac OS. Apple...
In SCSI standards for transferring data between computers and peripheral devices, often computer storage, commands are sent in a Command Descriptor Block...
returned by a SCSI device. When a SCSI target device returns a check condition in response to a command, the initiator usually then issues a SCSI Request Sense...
described before the introduction of SATA as ATA), Serial ATA (SATA), SCSI, Serial Attached SCSI (SAS), and Fibre Channel. Bridge circuitry is sometimes used to...
or SANoIP mapping of FCP over IP iSCSI, mapping of SCSI over TCP/IP iSCSI Extensions for RDMA (iSER), mapping of iSCSI over InfiniBand Network block device...
devices. The terms are primarily used to refer to devices for connecting SCSI, SAS, NVMe, Fibre Channel and SATA devices. Devices for connecting to FireWire...
device addressed by the SCSI protocol or by Storage Area Network protocols that encapsulate SCSI, such as Fibre Channel or iSCSI. A LUN may be used with...
HyperSCSI is an outdated computer network protocol for accessing storage by sending and receiving SCSI commands. It was developed by researchers at the...
USB Attached SCSI (UAS) or USB Attached SCSI Protocol (UASP) is a computer protocol used to move data to and from USB storage devices such as hard drives...
placed at the end of a transmission line or daisy chain bus (such as in SCSI), and is designed to match the AC impedance of the cable and hence minimize...
A SCSI Status Code is used to determine the success or failure of a SCSI command. At the end of any command, the target returns a Status Code byte which...
drive with both SCSI and IEEE 1284 connections; SCSI ID limited to ID 5 and 6). Parallel port external Zip drives are actually SCSI drives with an integrated...
(Advanced SCSI Programming Interface) is an Adaptec-developed programming interface which standardizes communication on a computer bus between a SCSI driver...
13h will be "caught" by the SCSI option ROM (or "SCSI BIOS"), allowing it to respond for disks that may exist on the SCSI bus. Before it had hooked the...
block storage. Fibre Channel Protocol (FCP) is a protocol that transports SCSI commands over Fibre Channel networks. FICON is a protocol that transports...
The SCSI implementation of the Plus was engineered shortly before the initial SCSI spec was finalized and, as such, is not 100% SCSI-compliant. SCSI ports...
SCSI target devices provide a number of SCSI log pages. These can be interrogated by a Log Sense command and in some cases can be set by a Log Select command...
(SCSI ID or PID). A SCSI device can have an optional SCSI device name which must be unique within the SCSI domain in which the SCSI device has SCSI ports...
introduced in 1993. The line initially focused on high-capacity, high-performance SCSI hard drives until introducing ATA models in 1999 and SATA models in 2002...
INCITS T13 and an INCITS T10 subcommittee (SCSI), a subgroup of T10 responsible for Serial Attached SCSI (SAS). The remainder of this article strives...
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