Glossary

If you do not find the term you are looking for, see the IBM® Glossary of Computing Terms.

A

ac

alternating current

advanced interactive executive (AIX®)

IBM's implementation of the UNIX® operating system. The RS/6000® system, among others, runs the AIX operating system.

AES

Advanced encryption standard

AIX

See advanced interactive executive.

Advanced library management system (ALMS)

The next generation of IBM's patented Multi-Path Architecture. ALMS enables logical libraries to consist of unique drives and ranges of VOLSERs, instead of fixed locations. It offers the ability to assign tape drives to any logical library by using the IBM System Storage™ Tape Library Specialist web interface. Logical libraries can also be added, deleted, or easily changed without disruption.

American National Standard Code for Information Interchange

A 7-bit coded character set (8 bits, including parity check) that consists of control characters and graphic characters.

ASCII

See American National Standard Code for Information Interchange.

authentication

The process of recognizing a user through a valid combination of user ID and password.

local authentication

Each machine maintains an internal database of user IDs, with corresponding passwords and roles.

Storage Authentication Service policy authentication

A Role-Based Access Control method of authentication that uses Lightweight Directory Access Protocol (LDAP) to create a central repository for storage and management of user IDs, passwords, and roles.

B

beginning of tape (BOT)

The location on a magnetic tape that indicates the beginning of the permissible recording area.

C

Call Home

A communication link established between a product and a service provider. The product can use this link to place a call to IBM or to another service provider when it requires service. With access to the machine, service personnel can perform service tasks, such as viewing error and problem logs or initiating trace and dump retrievals.

CE

See customer engineer.

CLI

See command line interface.

command line interface (CLI)

A type of computer interface in which the input command is a string of text characters.

concurrent

Refers to diagnostic, maintenance, or replacement procedures that can be performed on a system without interrupting customer applications.

control unit (CU)

A device that controls input and output operations of one or more devices.

control unit function

A device that contains the functional logic for controlling the input and output operations at one or more devices.

customer engineer (CE)

Provides on-site services to install, repair, or do problem resolution. The CE is the primary, on site IBM contact for most IBM customers. Synonymous with field engineer and service support representative (SSR).

D

DDM

See disk drive module

DFSMS

Data facility system managed storage

An operating environment that helps automate and centralize the management of storage. To manage storage, DFSMS provides the storage administrator with control over data class, storage class, management class, storage group, and automatic class selection routine definitions.

disk drive module (DDM)

A field-replaceable unit that consists of a single disk drive and its associated packaging.

E

EEPROM

See electrically erasable programmable read only memory.

EIA

See Electronics Industries Association.

EIA unit

A unit of measure established by the Electronic Industries Association that is equal to 44.45 mm (1.75 in.)

electrically erasable programmable read only memory (EEPROM)

A rewritable memory chip that holds its content without power. EEPROMs are bit or byte addressable at the write level, which means either the bit or byte must be erased before it can be rewritten. In flash memory, which evolved from EEPROMs and is almost identical in architecture, an entire block of bytes must be erased before writing. In addition, EEPROMs are typically used on circuit boards to store small amounts of instructions and data, whereas flash memory modules hold gigabytes of data for digital camera storage and hard disk replacements.

electromagnetic compatibility

The design and test of products to meet legal and corporate specifications dealing with the emissions and susceptibility to frequencies in the radio spectrum. Electromagnetic compatibility is the ability of various electronic equipment to operate properly in the intended electromagnetic environment.

Electronic Industries Association (EIA)

An organization of electronics manufacturers that advances the technological growth of the industry, represents the views of its members, and develops industry standards.

electrostatic discharge (ESD)

The flow of current that results when objects having a static charge come into close enough proximity to discharge. Also refers to an undesirable discharge of static electricity that can damage equipment and degrade electrical circuitry.

EMC

See electromagnetic compatibility.

environmental recording, editing, and printing (EREP)

The program that formats and prepares reports from the data contained in the error recording data set.

EPO

emergency power off

equipment check

An asynchronous indication of a malfunction.

EREP

See environmental recording, editing, and printing.

ESD

See electrostatic discharge.

F

factoring ratio

The ratio determined by the nominal data divided by the physical data in the repository.

FC

See feature code.

feature code

A code used by IBM to process hardware and software orders.

fibre channel connection

A fibre channel communication protocol designed for IBM mainframe computers and peripherals.

FICON®

See fibre channel connection.

field replaceable unit

An assembly that is replaced in its entirety when any one of its components fails.

FRU

See field replaceable unit.

functional microcode

Microcode that is resident in the machine during normal customer operation.

G

Global File System (GFS)

This is a shared disk file system for Linux® computer clusters. This file system type is needed for the ProtecTIER® repository.

graphical user interface (GUI)

A type of computer interface that presents a visual metaphor of a real-world scene, often of a desktop, by combining high-resolution graphics, pointing devices, menu bars and other menus, overlapping windows, icons and the object-action relationship.

GUI

See graphical user interface.

H

Heartbeat Call Home record

Machine operating and service information sent to a service machine. These records might include such information as feature code information and the logical configuration information for a product.

I

IEEE

See Institute of Electrical and Electronics Engineers.

input/output (I/O or IO)

A device, process, channel, or communication path involved in data input, data output, or both.

I/O or IO

See input/output.

Institute of Electrical and Electronics Engineers (IEEE)

A professional society accredited by the American National Standards Institute (ANSI) to issue standards for the electronics industry.

initial program load (IPL)

The process that loads the system programs from the system auxiliary storage, checks the system hardware, and prepares the system for user operations. This process is also called boot.

K

KVM

Keyboard, video, mouse.

L

LED

See light-emitting diode.

light-emitting diode (LED)

A semiconductor device that emits visible light when an electric current passes through it. The light is not particularly bright, but in most LEDs it is monochromatic, occurring at a single wavelength. The output from an LED can range from red (at a wavelength of approximately 700 nanometers) to blue-violet (about 400 nanometers).

logical unit number (LUN)

In the small computer system interface (SCSI) standard, a unique identifier used to differentiate devices, each of which is identified as a logical unit.

logical volume

A collection of physical partitions organized into logical partitions, all contained in a single volume group. Logical volumes are expandable and can span several physical volumes in a volume group.

longwave laser (LW)

A longwave laser is a type of fiber-optic cabling that is based on 1300-mm lasers and supports link speeds of 1.0625 Gbps. LWL also refers to the type of gigabit interface converter (GBIC) or small form-factor pluggable (SFP).

LUN

See logical unit number.

LW

See longwave laser.

M

machine reported product data (MRPD)

This information is sent to IBM Service as part of the Heartbeat Call Home function when an error is detected.

maximum transmission unit (MTU)

The largest possible unit of data that can be sent on a given physical medium in a single frame. For example, the maximum transmission unit for Ethernet is 1500 bytes.

Mb/s

One Mebibit per second (Mibit/s) = 2²⁰ bits = 1,048,576 bits per second.

microcode

One or more microinstructions.

A code, representing the instructions of an instruction set, implemented in a part of storage that is not program addressable.

To design, write, and test one or more microinstructions. See also microprogram.

microprogram

A group of microinstructions that when executed performs a preplanned function. The term microprogram represents a dynamic arrangement or selection of one or more groups of microinstructions for execution to perform a particular function. The term microcode represents microinstructions used in a product as an alternative to hard-wired circuitry to implement certain functions of a processor or other system component.

modal page

A child page that has to be addressed before the user can continue to operate the parent application.

mount

To place a data medium in a position to operate.

MRPD

See machine reported product data.

MTU

See maximum transmission unit.

N

non-concurrent

Refers to diagnostic, maintenance, or replacement procedures that interrupt customer applications when they are performed on the system.

O

offline

Pertaining to the operation of a functional unit that is not attached to a controlling device such as a mainframe or a control unit.

online

Pertaining to the operation of a functional unit that is attached to a controlling device such as a mainframe or a control unit.

P

PCA

See power control assembly.

PDF

See portable document format.

portable document format

A standard specified by Adobe® Systems, Incorporated, for the electronic distribution of documents. PDF files are compact; can be distributed globally via e-mail, the Web, intranets, or CD-ROM; and can be viewed with Adobe Acrobat Reader.

power control assembly (PCA)

Refers to the power connections for cable that are part of the system design. These connections are made by manufacturing before the machine is shipped to the customer.

R

RAID

See redundant array of independent disks.

redundant array of independent disks

A collection of two or more disk physical drives that present to the host an image of one or more logical disk drives. In the event of a single physical device failure, the data can be read or regenerated from the other disk drives in the array due to data redundancy.

RAID-5

Uses block-level striping with parity data distributed across all member disks.

RAID-6

Uses block-level striping with two parity blocks distributed across all member disks.

RAID-10

Uses striping on a mirrored array of member disks.

S

service information messages (SIM)

A message, generated by a storage subsystem, that is the result of error event location and analysis. A SIM indicates that some service action is required.

service support representative (SSR)

Provides on site services to install, repair, or do problem resolution. The SSR is the primary, on site IBM contact for most IBM customers. Synonymous with customer engineer (CE) and field engineer.

shelf

A container for cartridges that do not belong to any library. ProtecTIER Manager displays a view of the shelf and allows access to the cartridges in the shelf.

SIM

See service information message.

storage virtualization

A methodology used to decrease the logical volume access time of data storage and retrieval.

T

Takeover

The process where the disaster recovery site takes over production from the primary site by changing ownership of all volumes. This is initiated by the user when they have determined that the data at the production site is not recoverable. The disaster recovery site has read/write access to all volumes.

TAC

technical area code

tape controller

A device that provides the interface between a system and one or more tape drives. Synonymous with control unit.

TCDB

tape catalog database

TCP/IP

Transmission Control Protocol/Internet Protocol. With regard to a tape library, the protocol used for the LAN communication path between the mainframe and the Library Manager.

TKLM

Tivoli® Key Lifecycle Manager

TMG

Tape Management Gateway

TSM

Tivoli Storage Manager

U

UART

universal synchronous receiver and transmitter

URC

unit reference code

The last 4 characters of the SRC.

A group of numbers displayed on the console or control panel that identifies failing parts, system or device states, or system or device status conditions.

USB

universal serial bus

A plug-and-play (Intel® standard) interface between a computer and add-on devices (such as keyboards and printers). The USB allows a user to add a new device to a computer without having to add an adapter card or to turn the computer off.

utilities

Utility programs

utility programs

A computer program used for general support of the processes of a computer, for instance, a diagnostic program

V

V ac

volts alternating current

Virtual volume

Data storage on DDMs that shows the same characteristics to a host application as a physical tape volume and contains data written or read through a virtual tape drive

VOLSER

volume serial number

An identification number in a volume label that is assigned when a volume is prepared for use on the system.

VPD

Vital Product Data

The information contained within a component that requires nonvolatile storage used by functional areas of the component, and information required for manufacturing, RAS, and engineering.

VTS

Virtual Tape Server

W

WAN

Wide area network: a network that provides communication services between devices in a geographic area larger than that served by a local area network (LAN) or a metropolitan area network.

WBEM

Web-Based Enterprise Management

word

A character string that is convenient for some purpose to consider as an entity

WORM

write-once,-read-many

Any storage medium that allows data to be written only once per storage unit and never changed for secure archival purposes. The medium is allowed to add new content that does not change previously written units of storage.

WOT

Write-ownership takeover

Write-mount count

A 16-bit sister value of WWID (World Wide Identifier) that represents the total number of times an LWORM volume is mounted and modified due to a write operation. This value is seeded to zero for a newly bound LWORM volume prior to the first write from BOT (beginning of tape).

WTI

World trade interplant

WWID

World Wide Identifier

A world-unique, 12 byte, 24 hex digit value assigned to a media cartridge that identifies a volume beyond volume serial. This identifier is also referred to as a CUID.

WWNN

World wide node name

A unique 64 bit identifier for a host containing a fibre channel port.