Document revision date: 19 July 1999

An alphabetical list of terms used in the OpenVMS System Manager's Manual and their definitions follow.

access control list (ACL): A protection mechanism using a more refined level of protection than that available with UIC-based protection. ACLs can be used to grant or deny access to individual users or groups of users.

access mode: Any of the four processor access modes in which software executes. Processor access modes prevent system software from inadvertently performing operations that might damage the system. Processor access modes are in order from most to least privileged and protected: kernel, executive, supervisor, and user. When the processor is in any mode other than kernel mode, the processor is inhibited from executing privileged instructions.

account: Each system user has an account. When you log in, you log in under a particular account name and number. This number informs the system where your files are and what kind of access to other files and system facilities you should be given.

accounting files: Files where the system stores information about resource use. Compare with current accounting file.

active set: In a multiprocessing system, the subset of processors that have successfully run power-on diagnostics and are actively participating in system operations. Compare with available set.

active values: With system parameters, the set of values that is stored in memory and is used by the active system. When the system boots, it reads into memory the current values stored in a parameter file on disk.

adjacent node: In a network, a node that is connected to your node by a single physical line.

allocation class: In an OpenVMS Cluster environment, for devices that are dual-ported between two computers, a numeric value used to create a unique, path-independent device name.

answer file: A file in the form SYS$UPDATE:product.ANS. The file is created when you install a product initially, and you specify the Auto-Answer option. The file contains a record of the answers you entered when you ran VMSINSTAL.COM to install that product initially.

application service: A LAT service in which LAN users can access only a specific program. Contrast with general timesharing service.

area router: In a network, a node that performs routing operations between areas and within its own area. Also called a level 2 router. Compare with level 1 router.

autoconfiguration: Autoconfiguration is the process of discovering the hardware devices on a system and loading the appropriate device drivers.

autostart feature: A feature that simplifies startup and ensures high availability of execution queues in an OpenVMS Cluster environment. It lets you perform the following actions:

• Start all autostart queues on a node with a single command
• Specify a list of nodes (within an OpenVMS Cluster environment) to which a queue can automatically fail over if necessary.

autostart queue: An execution queue that takes advantage of the autostart feature. When you create a queue, you can designate it as an autostart queue.

available set: In a multiprocessing system, those processors that have successfully completed the system's power-on hardware diagnostics and may or may not be actively involved in the system. Compare with active set.

backlink: In Files--11 disk structure, a pointer to the directory in which a file resides.

banner page: A specially formatted page that prints at the beginning and end of print jobs and files within print jobs. These pages are helpful in identifying and separating output jobs, and the files within those jobs, when they are printed.

base process priority: A base priority value that the system uses to schedule a process. Priorities range from a low of 0 to a high of 31; 0 through 15 are timesharing priorities and 16 through 31 are real-time priorities. Compare with job scheduling priority.

batch execution queue: An execution queue that can accept only batch jobs.

batch job: A detached process that sequentially runs one or more command procedures. The user defines the list of command procedures when submitting the job to a batch queue.

batch mode: An execution mode in which you can execute a command procedure by submitting the procedure to a batch queue. When resources are available, the system creates a detached process to execute the commands in the procedure. Usually, processes running in batch mode execute at a lower process priority, to avoid competing with interactive users for system resources.

beginning-of-tape (BOT) marker: A piece of photoreflective tape that delimits the beginning of the writable area on a tape volume.

binding: On an InfoServer system, a function that creates a virtual device unit on a local OpenVMS system.

block: On Files--11 disks, the basic unit by which disk space is allocated (512 8-bit bytes). On magnetic tape, the size of a block is determined by the user.

boot block: Virtual block 1 of the index file. The boot (or bootstrap) block is almost always mapped to the logical block 0 of the volume. The book block contains the location and size of the primary bootstrap image, which is used to boot the system. Certain processors, in order to boot, must read the boot block to obtain the location of the primary bootstrap image.

booting: Also called bootstrapping, the process of loading system software from the system disk into processor memory. You must install the operating system before you boot the system for the first time. See also conversational boot and nonstop boot.

bootstrapping: See booting.

bpi: Bits per inch; a measure used for characters of data on tape. Also called density.

caching: A performance enhancement in which the system stores information in memory; this includes information about a disk volume's free space, file identifications, quota file entries, and file headers.

capability: On VAX systems, software that makes the services of the vector processor available to system users.

cathedral windows: Segmented windows created from mapping windows; useful for reducing the overhead required to read large files. The Buffered I/O Byte Count Limit (BITLM) limits the number of cathedral windows a user can create.

circuit: In a network, a communications data path that connects adjacent nodes. A circuit is not a physical data path but, rather, a logical connection that operates over a physical connection (a line). All input and output (I/O) between nodes takes place over circuits.

cluster: On Files--11 media, a logical grouping of blocks; the basic unit by which disk space is allocated.

See also VAXcluster system, OpenVMS Cluster system.

CMIP: See Common Management Information Protocol.

command procedure: A file containing DCL commands and, optionally, data used by those commands. When you execute a command procedure, the system reads the file and executes the commands it contains. This eliminates the need for you to enter each command separately. You can use command procedures to efficiently perform routine tasks. A command procedure can also be executed in batch mode.

command string: The complete specification of a command, including the command name, command qualifiers, parameters, and parameter qualifiers. Because a command can be continued on more than one line, the term is used to define the entire command.

Common Management Information Protocol (CMIP): Draft standard for network management operations on which DECnet-Plus network management protocol is based. CMIP is used for encoding network management operations that can be performed on an entity. CMIP permits the exchange of information between a director and an agent. CMIP supersedes the Phase IV Network Information and Control Exchange (NICE) protocol.

Compact Disc Read-Only Memory (CD-ROM): Computer discs similar to the CD-ROMs used for audio applications. The major difference is that CD-ROM computer disc players have a digital (rather than an audio) interface.

configuration database: In a network, each node has a configuration database that includes information about the node and other nodes with which it can communicate. The configuration database is made up of a permanent database and volatile database.

connection manager: In an OpenVMS Cluster environment, the component that dynamically defines the OpenVMS Cluster system and coordinates participation of computers in the cluster.

conversational boot: A booting operation in which you stop to perform special operations---for example, to change system parameter values---before booting. Contrast with nonstop boot.

Conversational boot operations are common in programming research and development environments where you must alter operating conditions for experimentation, testing, and debugging.

Coordinated Universal Time (UTC): International standard for measuring time of day.

crash dump: When the operating system detects an unrecoverable error or an inconsistency within itself that causes the system to fail, it writes the contents of the error log buffers, processor registers, and memory into the system dump file.

crash history file: A file storing information about system crashes. Use the Crash Log Utility Extractor (CLUE) to display the contents of the crash history file to understand and resolve the issues responsible for crashes, and to obtain other useful data.

current accounting file: In an OpenVMS Cluster environment, an accounting file for a particular node. By default, the current accounting file is SYS$MANAGER:ACCOUNTNG.DAT.

current values: With system parameters, the set of values that is stored in the default parameter file on disk and are used to boot the system. When the system boots, it reads the current parameter values into memory to create active values.

cylinder: On a disk, consists of all tracks at the same radius on all recording surfaces of the disk.

data area: One of two divisions of CD-ROM volume space; includes the remaining volume space, beginning with logical sector 16.

data record storage: Within tape files, data records are stored in variable-size data blocks. Each block contains one or more records. RMS provides management of records.

DECevent: On Alpha systems, the event management utility that provides an interface between a system user and the operating system's event log files.

DECnet: Generic name for the software and hardware products that allow various Compaq operating systems to participate in a network. DECnet allows a system to function as a node in a network. See also DECnet Phase IV, DECnet-Plus for OpenVMS, and DIGITAL TCP/IP Services for OpenVMS.

DECnet Phase IV: Older version of DECnet; available for separate installation as a layered product.

DECnet-Plus for OpenVMS: The version of DECnet that is available with the installation procedure for the OpenVMS operating system. DECnet-Plus is Compaq's implementation of the Digital Network Architecture (DNA) Phase V.

default values: With system parameters, the set of values provided on your distribution kit and stored in the default list. These values allow you to boot any supported configuration.

density: A measurement, in bits per inch, used for characters of data on tape.

device: Hardware that allows access to storage media; also called drive.

device control library: A text library that contains user-written modules consisting of text or escape sequences. See also device control module.

device control library module: A user-written module in a device control library. Device control library modules can be used for the following purposes:

• With programmable printers, to insert device-dependent escape sequences that set up a printer for selected print options such as point size, character set, and bold or italic print.
• With both programmable and nonprogrammable printers, to insert text at specific points in the processing of a print job.

See also page setup module, reset module, and setup module.

device driver: A system component that controls I/O operations for a particular device type. For a device to function on a system, the device must be connected and the device driver must be loaded into memory.

DIGITAL TCP/IP Services for OpenVMS: Compaq implementation of the TCP/IP protocol suite and Internet services for OpenVMS Alpha and VAX operating systems.)

disk: Physical media on which files reside.

disk quota: A method for maintaining and enforcing limits on the amount of disk space available to users on a public volume. See also quota file.

drive: Hardware that allows access to storage media; also called device.

end node: In a network, a node that does not perform routing operations.

end-of-tape (EOT) marker: A piece of photoreflective tape that delimits the end of the writable area on a tape volume.

ERRFMT process: System process that periodically empties the error log buffers, transforms the descriptions of the errors into standard formats, and stores the formatted information in the error log file on the system disk.

error log dump file: On Alpha systems, file to which the contents of error log buffers are written (in addition to the system dump file). The error log dump file is provided so that the system can be updated on reboot to include error log entries that were created but not written at the time of a system crash.

error log file: The operating system automatically records device and CPU error messages in this file. The Error Log utility invokes the Error Log Report Formatter (ERF) to selectively report the contents of an error log file.

Error Log Report Formatter (ERF): A system component invoked by the Error Log utility to selectively report the contents of the error log file.

Ethernet: A single shared network channel, with all nodes having equal access to the channel. Ethernet offers local and remote connections as one integral network.

event classes: Categories of security-relevant events. The system always audits several event classes.

executable image: An image that can be run in a process. It is linked with the /EXECUTABLE qualifier (or without the /SHAREABLE qualifier) of the Linker utility.

execution queue: A queue that accepts batch or print jobs for processing. Compare with generic queue.

executive: A set of programs in the operating system that controls the running of routines that perform I/O, resource allocation, and program execution. See also executive routines.

executive mode: The second most privileged processor access mode. OpenVMS Record Management Services (RMS) and many system service procedures execute in executive mode.

executive routines: System routines that detect errors and events and write relevant information into error log buffers in memory. See also executive.

expiration date: The Files--11 On-Disk Structure uses the expiration date of a file to track the use of a file. The expiration date aids in the disposal of seldom-used files.

extent: On Files--11 volumes, contiguous blocks allocated to a particular file.

feedback: Information, continuously collected by the executive, about the amount of various resources the system uses to process its work load. When run in feedback mode, AUTOGEN analyzes this information and adjusts the values for any related system parameters.

field: In a UAF record, a portion of the record you modify with the Authorize utility. The values you assign to each field perform the following functions:

• Identify the user
• Define the user's work environment
• Control use of system resources

file: On Files--11 media, an array of consecutive virtual blocks, numbered 1 to n, plus a set of attributes with values. A file is either a data file or a directory file. Directories can contain both data files and directory files.

file banner page: A banner page that separates files within a job; users can override the file banner page settings you set for a queue.

file header: On a Files--11 volume, describes a portion of a file on the volume. File headers contain information such as the owner UIC, protection code, creation date and time, and access control list (ACL).

file operation: In the Backup utility, an operation that processes individual files or directories.

Files--11 On--Disk Structure: A logical structure given to information stored on a disk; it is a hierarchical organization of files, their data, and the directories needed to gain access to them.

Files--11 volume: A disk volume that uses Files-11 On-Disk Structure and is mounted on a device.

full backup: See image backup.

full names: On VAX systems, hierarchically structured DECnet-Plus node names that can be stored in a DECdns naming service. Full names on VAX systems can be a maximum of 255 bytes long.

gateway: In a TCP/IP network, a computer that is connected to two networks and routes packets from one to the other.

general timesharing service: A LAT service offering processing resources to users in the LAN. Contrast with application service.

generic batch queue: A generic queue that can direct jobs only to batch execution queues.

Generic batch queues are typically used in OpenVMS Cluster environments to distribute the batch work load across several nodes.

generic output queue: A generic queue can direct jobs to any output execution queue. Generic output queues are typically used to distribute the output work load among several identical printers.

generic queue: A queue that holds batch or print jobs until they are transferred to an execution queue for processing.

A generic queue holds a job until an appropriate execution queue becomes available to initiate the job. The queue manager then requeues the job to the available execution queue.

group volume: A volume available to all the users in a group. Compare to system volume.

header labels: On magnetic tape, labels containing information such as the file name, creation date, and expiration date. When you create a file on magnetic tape, the magnetic tape file system writes header labels immediately preceding the data block. To access a file on magnetic tape by the file name, the file system searches the tape for the header label set that contains the specified file name.

header resident image: A known image for which the header of the image file remains permanently resident in memory, saving one disk I/O operation per file access.

home block: A block in a Files--11 volume that identifies it as a Files-11 volume. Usually, the home block is the next block after the boot block (block 0). If for some reason the home block cannot be read (is physically unusable), an alternative block is selected for use as the home block. This block provides specific information about the volume and default values for files on the volume.

host: In a TCP/IP network, each end system connected to a TCP/IP network. Each host has a unique name and address. The local host is the system you are using, and the remote host is the system with which you are communicating.

identification record: A record of a file header that contains a summary of disk and volume characteristics.

IDP: See new domain part.

image: A collection of procedures and data bound together by the Linker utility to form an executable program. Executable programs can be executed (or run) by a process. Usually, executable programs have the file type .EXE.

image backup: Also called a full backup. A Backup utility operation that saves a copy of all the files on a disk (or volume) to a special file called a save set. See also image operation.

image compare: A Backup utility operation that compares the contents of entire volumes.

image copy: A Backup utility operation that creates a new Files--11 On-Disk Structure on the output disk and copies an entire volume; the image backup is a logical duplicate of the contents of the disk.

image operation: A Backup utility operation that processes all files on the input disk.

image registry: A file associated with the Image Registry facility. To continue using a compatible application image that depends on a previous operating system version, you can register the image in the Image Registry.

image restore: A Backup utility operation that initializes the output disk and restores an entire volume.

incremental backup: A Backup utility operation that saves only those files that have been created or modified since the most recent backup that was performed using the /RECORD qualifier. (The /RECORD qualifier records the date and time that the files are backed up.)

incremental restore: A Backup utility operation that restores an incremental save set.

InfoServer system: An Ethernet-based, high-performance, virtual device server. The InfoServer system can serve physical device media and sets of logical disk blocks to client systems in a local area network (LAN). Systems running the appropriate client software can connect to virtual devices served by the InfoServer system and use them as though they are locally attached devices.

initialization file: In certain utilities, a file used each time you invoke the utility. In the initialization file, you can perform tasks such as defining keys and setting up your environment.

installation procedure: The procedure for installing the operating system for the first time. Also, a procedure for installing a layered product.

IRG (interrecord gap): On magnetic tape, the interval of space between blocks.

job banner pages: banner pages that identify jobs; users cannot override job banner pages that you set for a queue. Compare with file banner pages.

job controller: The system process that creates a process to perform the tasks in a batch job.

job scheduling priority: A priority value that the system uses to schedule batch or print jobs in a queue. Job scheduling priorities range from a low of 0 to a high of 255. Compare with base process priority.

kernel mode: The most privileged processor access mode. The operating system's most privileged services, such as I/O drivers and the pager, run in kernel mode. When in kernel mode, the processor has complete control of, and responsibility for, the system.

key processes: Processes that are dumped immediately following PT, S0/S1, and S2, including transition pages that link back. The system manager can designate additional processes to be treated as key processes. Key processes have priority over other processes in a dump, thus ensuring that the selected processes are successfully written when the dump file is too small to contain all processes.

known file list: An internal data structure on which the system defines known images. Each entry in the known file list identifies the file name of the known image and the attributes with which it was installed.

known image: An image installed with the Install utility (INSTALL). When you install an image, the image is assigned attributes and becomes known to the system.

LASTport protocol: A specialized LAN transport protocol, implemented by the InfoServer software, that allows many clients to access InfoServer systems and perform reliable device read and write operations.

The LASTport/DISK protocol and LASTport/TAPE protocol are specialized disk and tape protocols that use the LASTport protocol.

See also InfoServer system.

LAT protocol: Protocol, implemented by the LAT software, that allows the operating system to offer resources, or LAT services that terminal servers can access.

LAT service announcements: Multicast messages sent by LAT service nodes and used to create a database of service nodes available.

LAT service node: A system that supports incoming LAT connections or a system that offers LAT services.

LAT services: Computing resources made available to users in the LAN through the LAT software. A LAT service can be a general timesharing service or an application service.

level 1 router: In a network, a node that performs routing operations within a single area. Compare with level 2 router.

level 2 router: In a network, a node that performs routing operations between areas and within its own area. Also called an area router. Compare with level 1 router.

license: Many software vendors provide software to their customers under an agreement called a license. Although the term license can have specific legal connotations, for the purpose of this manual a license refers to the authorization you have to use a product.

The License Management facility (LMF) lets you register, manage, and track software licenses on line. See also Product Authorization Key (PAK).

lines: In a network, physical data paths that connect adjacent nodes. Communications lines connect your computer to the DECnet network.

In a TCP/IP network, a line is the physical path over which data can pass from one host to another.

load address: The location in memory (specified in hexadecimal notation) to which the system loads the bootstrap image.

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