Dell TL2000 manual

beginning of tape. It means that policy is determined on writes at LB (logical block) zero (the first block in the partition). Appending to a tape [or overwriting at a non-zero LB] does not change the policy already in use for that tape.

Border Gateway Protocol (BGP). BGP is the core routing protocol of the Internet. It works by maintaining a table of IP networks or ’prefixes’ which designate network reachability among autonomous systems (AS).

browser. A client program that initiates requests to a Web server and displays the information that the server returns.

buffer. A routine or storage used to compensate for a difference in rate of flow of data or time of occurrence of events, when transferring data from one device to another.

bus. A facility for transferring data between several devices located between two end points, only one device being able to transmit at a given moment.

byte. A string consisting of a certain number of bits (usually 8) that are treated as a unit and represent a character. A fundamental data unit.

C

capacity. The amount of data that can be contained on storage media and expressed in bytes of data.

cartridge storage slot. Individual slot located within a magazine that is used to house tape cartridges.

caution (notice). A word to call attention to possible personal harm to people. Contrast with attention and danger.

centimeter (cm). One one-hundredth of a meter (0.01 m). Approximately 0.39 inch.

channel command. An instruction that directs a data channel, control unit, or device to perform an operation or set of operations.

char. Character.

CHK. Check.

cleaning cartridge. A tape cartridge that is used to clean the heads of a tape drive. Contrast with data cartridge.

command. A control signal that initiates an action or the start of a sequence of actions.

compact disc (CD). A disc, usually 4.75 inches in diameter, from which data is read optically by means of a laser.

compression. The process of eliminating gaps, empty fields, redundancies, and unnecessary data to shorten the length of records or blocks.

concurrent. Refers to diagnostic procedures that can be run on one control unit while the rest of the subsystem remains available for customer applications.

contingent connection. A connection between a channel path and a drive caused when a unit check occurs during an I/O operation.

controller. A device that provides the interface between a system and one or more tape drives.

control path drive. A drive that communicates messages from the host computer to the library in which the drive is installed.

CP. Circuit protector.

ctrl. Control.

CU. Control unit.

D

danger (notice). A word to call attention to possible lethal harm to people. Contrast with attention and caution.

data. Any representations such as characters or analog quantities to which meaning is or might be assigned.

data buffer. The storage buffer in the control unit. This buffer is used to increase the data transfer rate between the control unit and the channel.

data cartridge. A tape cartridge dedicated to storing data. Contrast with cleaning cartridge.

data check. A synchronous or asynchronous indication of a condition caused by invalid data or incorrect positioning of data.

dc. Direct current.

DCS. Designated Cleaning Slot

degauss. To make a magnetic tape nonmagnetic by means of electrical coils carrying currents that neutralize the magnetism of the tape.

degausser. A device that makes magnetic tape nonmagnetic.

degradation. A decrease in quality of output or throughput or an increase in machine error rate.

degraded. Decreased in quality of output or throughput or increased machine error rate.

Density reporting. This setting determines whether the drive shows or masks encryption. This settings

H-2Dell PowerVault TL2000 Tape Library and TL4000 Tape Library User's Guide