IBM T400F manual Glossary

the drive. Log sense data is used to diagnose problems, especially if the problems are intermittent.

SCSI wrap plug. A connector mechanism that connects to a SCSI port for the purpose of testing the Ultrium 2 Tape Drive’s circuitry for the SCSI interface.

SCSI wrap test. A diagnostic that can be run on the Ultrium 2 Tape Drive to determine whether the circuitry functions properly to and from the SCSI connector.

second. One sixtieth of a minute.

selection time-out.Following the selection of an option (for example, a data transfer), the period of time during which it is determined that there is a bad connection between the server and the drive.

sense data. Data that describes an I/O error. Sense data is presented to a server in response to a Sense I/O command.

serial interface. An interface that sequentially or consecutively executes two or more operations in a single device, such as an arithmetic and logic operation.

server. A functional unit that provides services to one or more clients over a network. Examples include a file

server, a print server, or a mail server. The IBM Eserver pSeries, IBM Eserver iSeries, HP, and Sun

are servers. Synonymous with host.

ship group. The group of supplies, cords, or documentation that is shipped with the Ultrium 2 Tape Drive.

shipping environment. The temperature, relative humidity rate, and wet bulb temperature of the environment to which the Ultrium 2 Tape Drive is exposed when it is transferred from one location to another.

short-wave cable. In Fibre Channel technology, a laser cable that uses a wavelength of 780 nanometers and is only compatible with multimode fiber.

single-character display. Located at the front of the Ultrium 2 Tape Drive, an LED that presents an alphabetical or numeric code which represents a diagnostic or maintenance function, error condition, or informational message.

sleep mode. A power-management function that causes the Ultrium 2 Tape Drive’s electronics to automatically enter a low-power mode by which to conserve energy.

Small Computer Systems Interface (SCSI). A standard used by computer manufacturers for attaching peripheral devices (such as tape drives, hard disks, CD-ROM players, printers, and scanners) to computers (servers). Pronounced ″scuzzy.″ Variations of the SCSI interface provide for faster data transmission rates than

standard serial and parallel ports (up to 160 megabytes per second). The variations include:

vFast/Wide SCSI: Uses a 16-bit bus, and supports data rates of up to 20 MBps.

vSCSI-1: Uses an 8-bit bus, and supports data rates of 4 MBps.

vSCSI-2: Same as SCSI-1, but uses a 50-pin connector instead of a 25-pin connector, and supports multiple devices.

vUltra SCSI: Uses an 8- or 16-bit bus, and supports data rates of 20 or 40 MBps.

vUltra2 SCSI: Uses an 8- or 16-bit bus and supports data rates of 40 or 80 MBps.

vUltra3 SCSI: Uses a 16-bit bus and supports data rates of 80 or 160 MBps.

vUltra160 SCSI: Uses a 16-bit bus and supports data rates of 160 MBps.

soft addressing. Pertaining to the Fibre Channel drive (Model T400F), a method that enables the drive to dynamically arbitrate its AL_PA with other Fibre Channel devices on the loop. The AL_PA enables the drive to communicate with other devices.

software. Programs, procedures, rules, and any associated documentation pertaining to the operation of a computer system.

speed matching. A technique used by the Ultrium 2 Tape Drive to dynamically adjust its native (uncompressed) data rate to the slower data rate of a server. Speed matching improves system performance and reduces backhitch.

status light. Located at the front of the Ultrium 2 Tape Drive, an LED that can be green or amber, and (when lit) solid or flashing. The condition of the light represents the state of the drive.

Storage Area Network (SAN). A high-speed subnetwork of shared storage devices. A SAN’s architecture makes all storage devices available to all servers on a LAN or WAN. As more storage devices are added to a SAN, they too will be accessible from any server in the larger network. Because stored data does not reside directly on any of a network’s servers, server power is used for business applications, and network capacity is released to the end user.

storage environment. The temperature, relative humidity rate, and wet bulb temperature of the environment in which the Ultrium 2 Tape Drive is nonoperational and is being kept for future use.

subscription channel connector (SC). A push-pull type of optical connector that features high density, low loss, low backreflection, and low cost.

switch. A network infrastructure component to which multiple nodes attach. Unlike hubs, switches typically have the ability to switch node connections from one to

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