Glossary

This glossary defines terms used in this manual.

Click letter for quick access: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

attribute-value pair

In a product kit's key file, attribute-value pairs specify the names and values of the attributes of the kit, such as the name and version of the product. Attribute-value pairs control how the kits utility builds the kit and how the setld utility installs it.

B

Backus-Naur form

A conventional notation for describing context-free grammars, commonly used for defining syntax in computer languages. It is named for John Backus, developer of FORTRAN, and Peter Naur, developer of ALGOL. The term BNF is often used to refer to grammar specifications based on this form.

See also postfix

backward link

A backward link is a symbolic link from the directories in a layered product area to files in the standard hierarchy. The subset control program for a product creates backward links during installation.

boot utility

The boot utility performs the initial installation and bootstrap of the operating system. You invoke the boot utility from the >>> console prompt. Refer to your hardware documentation for information about valid parameters for the boot utility on your system.

C

CDSL

A context-dependent symbolic link (CDSL) is a special form of symbolic link that dynamically resolves to a member-specific file, depending upon the cluster member accessing the file. CDSLs make it possible to maintain system-specific configuration and data files on file systems shared by the cluster.

See also cluster, cluster member, member-specific file, shared file

cluster

A loosely-coupled collection of servers that share storage and other resources, providing high availability of applications and data. A cluster consists of communications media, member systems, peripheral devices, and applications. One system can form a single-member cluster.

See also cluster alias, cluster member

cluster alias

An IP address used to address all or a subset of the cluster members. A cluster alias makes some or all of the systems in a cluster look like a single system when viewed from outside the cluster.

See also cluster, cluster member

cluster member

A system configured with TruCluster Server software that is capable of joining a cluster. A cluster member must be physically connnected to a private physical bus for intracluster communications and at least one shared SCSI bus.

See also cluster

compression flag file

The compression flag file is an empty file whose name consists of the product code and the version number with the string comp as a suffix; for example, OAT100.comp. If the compression flag file exists, the setld utility knows that the subset files are compressed.

context-dependent symbolic link

See CDSL

control file

One of a collection of files that the kits utility places in the instctrl directory. These files include the compression flag file, image data file, subset control file, subset inventory file, and subset control programs.

D

Dataless Management Services

See DMS

DMS

Dataless Management Services. A service where a server maintains the root ( / ), /usr, and /var file systems for client computer systems connected to the server by a local area network (LAN).

data hierarchy

In the kit-building directory structure, the data hierarchy contains the files that direct the setld utility in making subsets for the kit, such as the master inventory and key files. An scps subdirectory contains subset control programs written by the kit developer.

DCD format

A disk media format where files are written to any disk media (CD-ROM, hard disk, or diskette) as a UNIX file system (UFS). Subsets distributed in DCD format cannot be compressed.

See also tar format

dependency expression

A dependency expression is a postfix logical expression consisting of subset identifiers and relational operators to describe the current subset's relationship to the named subsets. Subset control programs evaluate dependency expressions under control of the setld utility.

See also Backus-Naur form, locking, postfix, subset dependency

direct CD-ROM format

See DCD format

distribution media

The distribution media for a product kit may be diskette, CD-ROM, or tape. A hard disk is sometimes referred to as a distribution media because it is used as the master copy for a CD-ROM kit. Hardware products can only be distributed on CD-ROM in Direct CD-ROM format.

E

/etc/sysconfigtab

See sysconfigtab database

/etc/kitcap

See kitcap database

F

forward link

A forward link is a symbolic link that connects a product file in the /opt, /usr/opt, or /var/opt directory to a standard UNIX directory, such as /usr/bin. Forward links allow layered products to be installed in a central location (the opt directories) and still be accessible to users through the standard directory structure.

G

gendisk utility

The gendisk utility is used to produce disk distribution media for a product kit. Refer to the gendisk(1) reference page.

See also kitcap database

gentapes utility

The gentapes utility is used to produce magnetic tape distribution media for a product kit. Refer to the gentapes(1) reference page.

See also kitcap database

H

hardware product

A hardware product includes kernel modules to support hardware devices. A hardware product kit, such as a device driver, can be installed during the initial installation and bootstrap linking of the operating system.

See also kernel product, layered product, NHD

I

image data file

The image data file is used by the setld utility to verify subset image integrity before starting the actual installation process, and contains one record for each subset in the kit.

See also setld utility

ISO 9660

ISO 9660 is an international file system standard adopted by major operating system manufacturers. A file system in this format can be read by most of the standard operating systems. Multiple specification levels allow different file naming conventions. ISO 9660-compliant file systems are usually on CD-ROM media.

K

kernel

The kernel is a software entity that runs in supervisor mode and does not communicate with a device except through calls to a device driver.

kernel product

A kernel product is a layered product that runs in kernel space. Users do not directly run kernel products, but the operating system and utilities access them to perform their work.

See also hardware product, layered product, user product

key file

A key file identifies the product that the kit represents. You create this file in the data directory before running the kits utility.

kit

A kit is a collection of files and directories that represent one or more layered products. It is the standard mechanism by which layered product modifications are delivered and maintained on the operating system.

See also layered product

kitcap database

The kitcap file (located in /etc/kitcap) is a kit descriptor database for the gentapes and gendisk utilities. This database contains product codes, media codes, and the names of the directories, files, and subsets that make up a product description used by these utilities to create distribution media.

The gentapes and gendisk utilities can specify substitute kitcap files in alternate locations.

See also gendisk utility, gentapes utility

kit descriptor database

See kitcap database

kits utility

The kits utility creates subsets according to the specifications you define in the master inventory file and key file.

See also key file, master inventory file, subset

L

layered product

A layered product is an optional software product designed to be installed as an added feature of the operating system.

See also hardware product, kernel product, user product

locking

In products installed by the setld utility, locking inserts a subset name in the lock file of another subset. Any attempt to remove the latter subset warns the user of the dependency. The user can choose whether to remove the subset in spite of the dependency.

See also dependency expression, subset dependency

M

master inventory file

A master inventory file lists all the product files and the subsets in which they belong. You create this file in the data directory by running the newinv utility. The file must exist before you can create the product subsets.

See also newinv utility, subset

member-specific file

A file used by a specific cluster member. The contents of a member-specific file differ for each cluster member, and each member has its own copy of a member-specific file.

See also cluster, cluster member, shared file

N

Network File System

See NFS

new hardware delivery

See NHD

newinv utility

The newinv utility creates the master inventory file from the list of files in the current working directory. The list does not contain all the information needed in the master inventory file. You must edit this file to include information about the subsets to which the files belong.

See also master inventory file

NFS

Network File System, an open operating system that allows all network users to access shared files stored on computers of different types. Users can manipulate shared files as if they were stored locally on the user's own hard disk.

NHD

New hardware distribution (NHD) provides delivery of support for new hardware without providing a new release of the operating system. The kit is usually provided on CD-ROM, and includes installation and testing instructions.

See also hardware product

O

output hierarchy

The output hierarchy contains the result of the kit-building process, including the subsets that make up the kit and installation control files to direct the setld utility during the installation of the product.

P

postfix

A form of logical expression where the operators follow the operands, rather than being placed between them. Also know as reverse Polish notation, or RPN.

See also Backus-Naur form

product code

A unique three-letter code that identifies the manufacturer of a product kit. The examples in this manual use the OAT product code for the fictional Orpheus Authoring Tools, Inc. You request a product code by electronic mail to Product@DSSR.enet.dec.com.

product kit

See kit

R

Remote Installation Services

See RIS

RIS

Remote Installation Services. A remote software distribution method where a server is set up to allow installation of software products over a local area network (LAN). RIS clients are registered on the RIS server to allow them access to specific software products. Using a RIS server makes installation of layered products faster and easier for all the clients on the network.

S

SCP

Subset control program. A program written by the kit developer to perform installation operations that the setld utility would not otherwise perform. The setld utility invokes the subset control program several times during the installation of the kit.

setld utility

The setld utility is the standard software management utility. It allows you to load, delete, inventory, configure, and extract software subsets. Refer to the setld(8) reference page.

shared file

A file used by all members of a cluster. There is only one copy of a shared file.

See also cluster, cluster member, member-specific file

source hierarchy

In the kit-building directory structure, the source hierarchy contains the files that make up the product. These files are grouped into subsets by the kits utility.

subset

The smallest installable software kit module that is compatible with the operating system's setld software installation utility. It contains files of any type, usually related in some way.

subset control program

See SCP

subset dependency

A subset dependency is the condition under which a given subset requires the presence (or absence) of other subsets in order to function properly.

See also dependency expression, locking

subset inventory file

The subset inventory file, generated by the kits utility, describes each file in the subset to reflect the exact state of the files in the source hierarchy from which the kit was built. The setld utility uses this file to duplicate that state, transferring an exact copy of the source hierarchy to the customer's system.

See also kits utility, setld utility, source hierarchy, subset

sysconfigdb utility

The sysconfigdb utility is a system management tool that maintains the sysconfigtab database.

See also sysconfigtab database

sysconfigtab database

The sysconfigtab database (located in the /etc/sysconfigtab file) contains information about the attributes of subsystems, such as device drivers. Device drivers supply attributes in sysconfigtab file fragments, which get appended to the sysconfigtab database when the subset control program calls the sysconfigdb utility during the installation of a kit.

See also sysconfigdb utility

T

tar format

A media format where the product files belonging to the same subset are written to the distribution media as a single file by the tar command. During installation, the setld utility uncompresses the files, then moves them onto the customer's system, preserving the files' original directory structure. Refer to the tar(1) reference page for information about using the tar command.

See also DCD format

U

user product

A user product is a layered product that runs in user space. Commands, utilities, and user applications fall into this category.

See also hardware product, kernel product, layered product