An acronym for application programming interface, an agreed-upon set of computer library routines to accomplish a task.


A device that has the ability to move media among various components (including slots,
media drives, media access ports, and transports) located in the device.  Autochangers automate the media loading, labeling, and mounting during backups and recovers.

backup group

A NetWorker client or clients configured to start backing up at a designated time.


A physical unit of disk storage used by OnLine Dynamic Server to store blobspace data.


Large objects, such as multimedia images, are stored in a binary large object space, a logical unit of storage composed of one or more chunks.  The physical data is stored in a blobpage, and a pointer to this physical location can be stored in a dbspace.


At the end of a backup, NetWorker saves the server's media database, NetWorker configuration files, and part of the server index to a special bootstrap save set, which provides vital information for recovering from a disk crash.  Save those printouts!

catalog tables

An ON–Bar component that tracks the compatibility of component versions, as well as backup objects and instances.


A physical unit of disk storage allocated by the system administrator for OnLine Dynamic Server data.


A program not invoked explicitly, which lies dormant waiting for a specified condition or conditions to occur.


Database object, a term which may refer to a blobspace, dbspace, or logical log file.


A logical unit of storage that consists of one or more chunks.  An OnLine Dynamic Server instance may consist of one dbspace or more.

emergency boot file

An ON–Bar ASCII file containing all of the information stored in the ON–Bar catalog tables that pertain to critical dbspaces.

fast recovery

ON–Bar executes a fast recovery by using the physical log to return OnLine Dynamic Server to the most recent point of known physical consistency.  Then, the logical logs are used to return OnLine Dynamic Server to logical consistency by rolling forward all committed transactions and rolling back all incomplete transactions.


A machine with disks that provide file storage to other machines on a network.


1.  A sub-tree of a UNIX file tree that is on a specific disk partition or other mount point.  2.  A method for storing files.

logical log

A record of OnLine Dynamic Server database transactions stored in a log file. It is used to execute a fast recovery and roll back transactions.

logical unit

A unit of temporary storage that keeps track of where physical units are located.

media manager

The NetWorker component that tracks save sets to backup volumes.  The nsrmmdbd daemon is responsible for making entries in the NetWorker online media index.


A method of transmitting multiple streams of data through the same channel.


A storage strategy that pairs a chunk of a defined dbspace or blobspace with an equal sized mirror chunk to enable users uninterrupted access if the primary database fails.

NetWorker client

A machine that can access storage management services from a NetWorker server.  Clients may be workstations, PC desktops, or fileservers with gigabytes of data.

NetWorker server

A machine on a network that runs NetWorker software, contains online client indexes, and provides storage management services to clients on a network.


A backup and recover utility that provides backup and recovery service to OnLine Dynamic Server.

OnLine Dynamic Server

INFORMIX OnLine Dynamic Server, considered by NetWorker as one or more instances of an INFORMIX RDBMS.

online client indexes

Databases on a NetWorker server that contain information pertaining to client backups and backup volumes.


A physical unit of disk storage used by OnLine Dynamic Server to read from and write to INFORMIX databases.

physical log

A set of contiguous disk pages where OnLine Dynamic Server stores “before” images of changed pages prior to physically recording the changes.

physical unit

A fixed-sized unit of disk storage allocated for data—chunks and blobpages are examples of physical units.


The initial default selections or configurations for several NetWorker features.


An acronym for Relational Database Management System.


A resource represents a component of the NetWorker software that describes the NetWorker server and its clients.  Devices, schedules, clients, groups, and pools are all examples of NetWorker resources.  Each resource contains a list of attributes, defining the parameters to use for the configured NetWorker resource.  Use the nwadmin program to configure NetWorker resources and their attributes.

roll forward (back)

Retroactively applying database transactions from a given point in time into the future (the past) using transaction logs.  This is a method for database recovery.


An acronym for Remote Procedure Call, a protocol that allows a program running on one host to execute code on another host without needing explicitly coded instructions.

save set

A set of files or a filesystem that NetWorker has backed up onto backup media during a backup session.  Save sets are assigned a save set ID, an internal number that identifies the backup session for subsequent restoration to primary disk.

shell prompt

Command line prompt, either % or $ (or # for super-user).

storage manager

An application that manages the storage devices and media used for ON–Bar backup and restore requests.  Database Module for Informix is a storage manager that connects NetWorker to ON–Bar through XBSA.


An acronym for X/Open® Backup Services, which connects NetWorker functionality to Informix ON–Bar.  XBSA specifies a programming interface, the XBSA API.