IBM T400F manual WAN. See wide area network, web. See World Wide Web

vital product data (VPD). Information about a product. Among other details, the VPD may include a model number, serial number, part number, or level of firmware.

volt. The SI (international) unit of potential difference and electromotive force. Formally defined as the difference of electric potential between two points of a conductor that carries a constant current of one ampere when the power dissipated between these points is equal to one watt.

VPD. Vital product data.

W

W.Watts.

WAN. See wide area network.

watt. The metric unit of power that is required to do work at the rate of one joule per second.

web. See World Wide Web.

wet bulb temperature. The temperature at which pure water must be evaporated adiabatically at constant pressure into a given sample of air in order to saturate the air under steady-state conditions. Wet bulb temperature is read from a wet bulb thermometer.

wide area network (WAN). A data communications network that is designed to serve an area of hundreds or thousands of miles (for example, national telephone networks).

World Wide Node Name. A unique, 8-byte identifier that is assigned by IBM Manufacturing to each Ultrium 2 Tape Drive and used to identify the drive’s SCSI logical unit.

World Wide Port Name. A unique, 8-byte identifier that is assigned by IBM Manufacturing to each Ultrium 2 Tape Drive and used to identify the physical port on the drive.

World Wide Web. A network of servers that contain programs and files. Many of the files contain hypertext links to other documents that are available through the network.

write. To make a permanent or transient recording of data in a storage device or on a data medium.

write protected. Applicable to a tape cartridge, the condition that exists when some logical or physical mechanism prevents a device from writing on the tape in that cartridge.

write-protect switch. Located on the LTO Ultrium Tape Cartridge, a switch that prevents accidental erasure of data. Pictures of a locked and unlocked padlock appear on the switch. When you slide the

switch to the locked padlock, data cannot be written to the tape. When you slide the switch to the unlocked padlock, data can be written to the tape.

Write/Read test. Part of the Test Head diagnostic, a procedure that determines whether the Ultrium 2 Tape Drive can correctly read from and write to tape.

Z

zoning. In Fibre Channel environments, the grouping of multiple ports to form a virtual, private, storage network. Ports that are members of a zone can communicate with each other, but are isolated from ports in other zones.

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