What is a small computer system interface?

The small computer system interface is a high -speed standard for connecting peripherals and computers. Also known as SCSI defines hardware connections and data exchange methods. For each supported peripheral type, SCSI defines the equipment -specific commands and protocols. SCSI is commonly used on servers and high -performance computers such as computers for sound and video production. It is often used with a redundant range of independent disks (RAID) and also network storage technology. The interface of a small computer system has several advantages over competing technologies. Its data cables can be quite long, making it easier to connect many external devices to the computer. More than one high -performance cable device can be active at a time and streamlines the storage -intensive application. For example, editing software can simultaneously read the dating of two hard drives and burning digital video (DVD). The SCSI parallel bus grew from eight bits to 16 bits and the width of the device with theShe doubled one hundred from one edition to another. Many motherboards included SCSI drivers or supported card adapter SCSI (HBA) host buses. Disk creators usually introduced their highest disks with SCSI support from other technologies. Integrated electronics (IDE) discs with low cost have remained a common choice for personal computers.

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small computer system interface organizes connected devices to logical units, goals and initiators. The device is initiator if it is able to initiate SCSI commands such as the SCSI driver. Goals such as disk units, DVDs and similar devices respond to initiators' requirements. Each target device can have more than one logic unit and many logical data blocks. In particular, high -capacity storage devices are usually accessible as multiple virtual units.

the log of the small computer system command defines the interfaceSeveral dozen operations. Included are the equipment management commands, the status of collecting and transferring data. There are four variants to read data from the device in addition to four different writing commands. The 32-bit cyclic redundancy (CRC32) method has been used for data transmissions since 1996, when the SCSI-3 specifications were released.

At the beginning of 2000, the SCSI bus bus frequency increased to 160 Megahertz (MHz) with the Ultra 640 specification. The parallel nature of SCSI began to cause ending and cabling problems at very high speeds. These problems were solved by reworking SCSI for transport data in series, rather than in parallel. Changes were implemented at the end of 2000 as a serial attached SCSI (SAS). Important variations, Fibre Channel Arbitrated Loop (FC-Al) uses very fast hours-4 Gigahertz (GHZ) -s with optical fiber cables.

SAS provides several advantages over parallel SCSI. Connecting devices are swappable, which means they canbe disconnected and connected as needed without switching on servers. SAS is compatible with storage for serial advanced technology (SATA). This allows lower and more popular SATA-Faculty to ide-K uses with advanced SCSI technology. SAS also improves the insulation of faults compared to the original interface of a small computer system.