another. A typical switch can facilitate several simultaneous bandwidth transmissions between different pairs of nodes.

T

TapeAlert. A patented technology and ANSI standard that defines conditions and problems that are experienced by tape drives.

TapeAlert flags. Status and error messages that are generated by the TapeAlert utility and display on the server’s console.

tape cartridge. A removable storage case that houses belt-driven magnetic tape that is wound on a supply reel and a takeup reel.

tape drive. See IBM TotalStorage LTO Ultrium 2 Tape Drive.

tape path. Within a tape drive, the channel in which the media moves.

tapeutil. Created by IBM, a utility program for LTO devices that connect to all supported servers except Windows NT and Windows 2000. tapeutil provides service aids for tape subsystems, offers a menu-driven tool for exercising or testing IBM tape and medium changer devices, and includes a command-line interface that is convenient for use in shell scripts.

terminate. To prevent unwanted electrical signal reflections by applying a device (known as a terminator) that absorbs the energy from the transmission line.

terminator. (1) A part that is used to end a SCSI bus.

(2)A single-port, 75-Bdevice that is used to absorb energy from a transmission line. Terminators prevent energy from reflecting back into a cable plant by absorbing the radio frequency signals. A terminator is usually shielded, which prevents unwanted signals from entering or valid signals from leaving the cable system.

TERMPOWER. Electrical power that is provided by a device (such as the Ultrium 2 Tape Drive) to a SCSI terminator so that the SCSI bus can function. To supply TERMPOWER, a jumper must be placed on pin 1 of the SCSI ID connector on the Ultrium 2 Tape Drive.

Test Head diagnostic. A test that determines whether the heads of the Ultrium 2 Tape Drive are operating properly and whether the drive can correctly read from and write to tape.

throughput. A measure of the amount of information that is transmitted over a network in a given period of time.

topology. In communications, the physical or logical arrangement of nodes in a network, especially the relationships among nodes and the links between them.

TotalStorage LTO Ultrium 2 Tape Drive. See IBM

TotalStorage LTO Ultrium 2 Tape Drive.

track. A linear or angled pattern of data that is written on a tape surface.

transfer rate. See data transfer rate.

two-node arbitrated loop. In Fibre Channel technology, the connection of two nodes that communicate directly (without the use of a switch) and use the same protocol.

two-node switched fabric loop. In Fibre Channel technology, the connection of two or more nodes that communicate by using a switch. The nodes may not use the same protocol.

U

Ultra160 LVD SCSI interface. See Small Computer

Systems Interface.

Ultrium 2 Tape Drive. See IBM TotalStorage LTO

Ultrium 2 Tape Drive.

uniform resource locator (URL). The address of an item on the World Wide Web. It includes the protocol followed by the fully qualified domain name (sometimes called the host name) and the request. The web server typically maps the request portion of the URL to a path and file name. For example, if the URL is

http://www.networking.ibm.com/nsg/nsgmain.htm, the protocol is http; the fully qualified domain name is www.networking.ibm.com; and the request is /nsg/nsgmain.htm.

unload. The act (performed by the drive) of unthreading tape from the drive’s internal tape path and returning it (with the leader block) to the tape cartridge.

unload button. Located at the front of the Ultrium 2 Tape Drive, a push button that, when depressed, rewinds the tape in a cartridge and ejects the cartridge from the drive. The unload button can also be used to place the tape drive in maintenance mode, scroll through maintenance functions, exit maintenance mode, force a drive dump, and reset the drive.

URL. See uniform resource locator.

utility. See utility program.

utility program. A computer program that supports computer processes. For example, a diagnostic program, a trace program, or a sort program.

V

Vdc. Volts dc (direct current).

114IBM TotalStorage LTO Ultrium 2 Tape Drive