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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.

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.

control files
The collection of files that the kits utility places in the instctrl directory are referred to as control files. These files include the compression flag file, image data file, subset control file, subset inventory file, and subset control programs.

data hierarchy
In the kit-building directory structure, the data heirarchy 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.

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 locking and subset dependency.

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.

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

foreign device kit
A foreign device kit contains a kernel product that must be installed during the initial installation and bootstrap linking of the Digital UNIX system. See also kernel product and layered product.

forward link
A foward 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.

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 layered 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 a Digital UNIX system. See also layered product.

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, and subset.

layered product
A layered product is an optional software product designed to be installed as an added feature of the Digital UNIX system. See also foreign device kit, kernel product, and 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.

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 data directory, newinv utility, and subset.

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.

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.

osfboot utility
The osfboot utility performs the initial installation and bootstrap of a Digital UNIX system.

RIS
See Remote Installation Services.

Remote Installation Services
Remote Installation Services (RIS) is a utility that lets users install kits into a RIS area for subsequent installation over a network onto client systems. Using a RIS server makes installation of layered products faster and easier for all the clients on the network.

SCP
See subset control program.

setld utility
The setld utility allows the transfer of the contents of a layered product kit to a customer's system.

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
A subset is the smallest installable component of a product kit for the setld utility. It contains files of any type, usually related in some way.

subset control program
A subset control program (SCP) is 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.

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 and locking.

sysconfigdb utility
The sysconfigdb utility is a system management tool that maintains the sysconfigtab database. See also /etc/sysconfigtab database.

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 layered product.