Software Installation Administrator's Guide

Chapter 1
Introduction

Silicon Graphics software is distributed on compact discs (CDs). A CD contains one or more software products and any special tools that the products require for installation. The purpose of the installation utility, inst(1M), is to transfer distribution software, which has an encoded format, to a hard disk in a format that is usable. The installation utility offers two user interfaces: a graphical interface, called Software Manager (documented in the Personal System Administration Guide); and a command line interface, called Inst (the subject of this guide).

The media containing installable software that you purchase from Silicon Graphics is referred to as a distribution. Most distributions are not specific to a particular model of Silicon Graphics computer; distributions ordinarily contain all versions of any hardware-specific files that might be required. Sometimes, however, a new server or personal workstation model is introduced, accompanied by a special software distribution. When this occurs, subsequent distributions are fully compatible with the new model.

Software Product Releases

A softwareproduct release contains all software required to support a given version of a product and the tools that are needed to install the release. One or more software product releases are contained in a distribution (see Figure 1-1 ).

When you install a software product release, files from previous versions of the release are automatically removed before the new files are installed (the exception is configuration files, which are saved if they contain local modifications). If a product release includes hardware-specific files, the installation utility automatically determines the file version that is needed on a particular model and installs that version.

Product releases may have prerequisites that require a particular installation order. They might also have compatibility requirements with other installed products. Inst protects users against potential problems by preventing installation if there are any unresolved incompatibilities or prerequisites (unless you override this safeguard).

Installation instructions, including prerequisites and incompatibilities information, are provided in the product release notes, which are always included as an installable subsystem of the product. You can read product release notes from the distribution CD using the CDgrelnotes or CDrelnotes command. Instructions for reading release notes are included in the CD jewel case insert.

Figure 1-1 illustrates the hierarchical structure of a software distribution that comprises three software product releases.

Figure 1-1 : Components of a Distribution

Anatomy of a Software Product

A software product is a collection of files that support either a germane system function or a specific application. A small number of products support critical functions and must be installed if the system is to operate; other products are not critical but optimize system operation and are recommended for installation by the manufacturer. A subset of required and recommended products is installed in servers and workstations before they leave the factory.

A software product comprises three elements: a product description, an installation database, and one or more images, which are composed of subsystems. Products are known to Inst by a shortname, which is an abbreviation of the formal product name. For example, the shortname of the Fortran 77 Compiler product is ftn_dev.

Product Descriptions

The product description is a file that contains information about product requirements and the installation environment for the product. The name of the product description file is the shortname for the product. For example, the name of the product description file for the Fortran 77 Compiler product is ftn_dev.

The Installation Database

The installation database is a file that contains installation information for every file in the product. The name of the installation database is the shortname with an .idb extension. For example, the name of the installation database for the Fortran 77 Compiler product is ftn_dev.idb.

Images

An image is a collection of installable files that perform a similar or complementary function. Typically, each software product contains at least two images. This modularity allows for tailoring installations. For example, it is possible to install the images that contain the executable programs of a product without installing the release notes image.

The name of an image is the product shortname followed by an extension that describes the image's function. For example, ftn_dev.sw is the image in the Fortran 77 Compiler product that contains files for program execution, and ftn_dev.man is the image that contains documentation files.

Subsystems

Images are composed of one or more subsystems. In a software product release, a subsystem is the smallest installable unit of software; the files that make up a subsystem cannot be installed individually (see Patch Releases for exceptions). Subsystems are assigned three-part names of the form product.image.subsystem. For example, ftn.sw.ftn and ftn.sw.utils are subsystems in the Fortran 77 Compiler product.

Required and Default Subsystems

Some subsystems in a software product are classified as default subsystems. Default subsystems support the basic functions of a product and are suggested for installation by the manufacturer. Where disk space is limited, the default subsystems serve as a guideline for determining what to install.

Some default subsystems are also classified as required subsystems. Required subsystems are critical to system operation; without them, IRIX will not operate. Inst prevents users from exiting an installation session if a required subsystem is available for installation but not installed (unless you choose to remove this safeguard).

When Inst is initialized, it makes preliminary selections of the subsystems to be installed during the session. If a target system contains no software, the preliminary selections always include all required and default subsystems; on targets with software installed, the default selections are all upgrades to the installed software that the distribution contains. When subsystems are displayed during an installation session, default subsystems are tagged with the letter d and required subsystems are tagged with the letter r .

Factory Installed Subsystems

Some subsystems from the eoe1, eoe2, motif_eoe, and other standard (no-cost) products are factory installed. The eoe1 and eoe2 products contain basic operating system software, utilities, and window system software. Extra-cost software options, such as Network File System (NFS) and compilers, are not factory installed.

To display the inventory of software that is installed on a system when you receive it, use the program showprods(1M):

% showprods

The output of showprods is one line for every product, image, and subsystem installed on the target. You can remove any factory installed software that you do not need, except required subsystems.

Patch Releases

A patch is a collection of one or more files that correct flaws in the performance, reliability, or security of a specific software product; a patch release is a distribution containing one or more patches. Each patch remedies a specific set of reported errors in the version of the product to which the patch applies.

Every patch is identified by a unique number, such as patchSG1234567, for example. The number is used in manufacturing to identify the collection of errors that the patch corrects. Typically, the reported errors that result in a patch release occur only under certain operating conditions. For this reason, installing a patch is only necessary if a system or site is experiencing a problem that the patch addresses.

The structure of a patch is similar to that of a software product (see Figure 1-1 ); however, the subsystems in a patch may span several products. For example, a patch for the FDDI product might contain file replacements for eoe1, eoe2, and fddivis subsystems. Patches are different from standard products in another important way: installing a patch replaces individual subsystem files, not the entire subsystem.

Patches are not dependent on other patches; they rely only on the software components in the original version of the affected product. A patch might be incompatible with other patches, however. Compatibility requirements and installation instructions are described in installable release notes, which you can read from the distribution CD using the CDgrelnotes or CDrelnotes command. Instructions for reading release notes are included in the CD jewel case insert.

Sources of Installable Software

The location of a software distribution is known as the distribution source ; the system receiving software during an installation is known as the target. A distribution source may be a CD that is mounted on the target, a CD that is mounted on a remote system, or a centralized directory on the network to which the distribution has been copied (see Figure 1-2 ). The directory on a distribution CD that contains the software is always called /dist.

A server or personal workstation that supplies a distribution source to remote targets is known as an installation server. An installation server can provide the distribution source from a local CD-ROM drive or from a disk directory that contains the installable images. A directory of installable software is known as a distribution directory. A distribution directory may contain software from several distributions.

Figure 1-2 illustrates local and remote distribution sources.

Figure 1-2 : Software Distribution Sources

Software Installation Methods

As of IRIX 5.3, most software installations can be performed without interrupting system operations. Installations that are performed without shutting down the system are referred to as live installations. Live installations are preferred because they are usually less time-consuming and because other system operations can be sustained during the installation session. It is important to understand that a live installation requires more disk space than miniroot installations; during live installations, Inst makes copies of files that are currently in use by the operating system or by applications.

In some cases, software can only be installed by a miniroot installation , which requires a system shutdown. During a miniroot installation, a special set of installation tools is copied to the swap partition of the system disk on the target. The software environment that these tools create for the installation is referred to as the miniroot. Only a portion of the IRIX operating system is available in the miniroot.

A miniroot installation is required under these conditions:

When the target is being upgraded from a pre-5.3 version of IRIX to IRIX 5.3 or later
When the release notes state that a miniroot installation is required
When the target has software problems that prevent successful live installations
When the target's system disk is new or empty
When recovering from severe system crashes (system recovery)

Introduction to Inst

Inst is invoked automatically when you do a miniroot installation; it is invoked from the command line when you do a live installation. After Inst is invoked, its Main menu is displayed.

Note: It might be useful to look ahead at Figure 5-1 for an illustration of the installation process while reading this Introduction.

Figure 1-3 illustrates the Main menu.

Figure 1-3 : The Main Menu for Inst

Automatic Initialization

During initialization, Inst reads the information in product descriptions and the installation database, makes preliminary selections of subsystems to install (see "Required ad Default Subsystems" ), and calculates estimated space requirements. Initialization is triggered when you issue the first command of the session that requires Inst to collect information about the distribution or the target software.

Using Main Menu Commands

The Main menu contains all commands that are needed to install and remove software. When the Main menu is displayed, Inst posts this prompt to accept command entries:

Inst>

Changing the Distribution Source

Inst always assumes that the installation target is the system where it is running. Inst selects a default distribution source, which is either the distribution source of the previous installation (during live installations) or local CD-ROM (during miniroot installations). You can specify a different distribution source using the from command.

Viewing the Software Inventory

The list command displays an inventory of the software on either the distribution or the target system. Displaying software inventories early in a session is helpful in deciding what software to install or remove. By default, the output of list displays the shortnames of subsystems in the distribution inventory, their size and description, and selection and installation information.

Using the view command, you can toggle the list command so that it displays either the distribution or the target inventory. The view command also focuses list output on different levels of the product hierarchy, so that you can display information about images or entire products. You can also use view to filter certain information from list displays.

Selecting and Installing Software

You can install the preliminary installation selections that Inst makes during initialization or change the selections before launching an installation. The install command selects items in the distribution inventory for installation; the remove command selects items on the target inventory for removal. The keep command selects items on either list for which no action should be taken. A special selection command, step, allows you to list and select software at the same time.

You can change selections as many times as necessary, so long as you do not issue the go command, which launches the installation.The go command initiates the installation and removal of software that you specified in your selections.

Handling Conflicts

Sometimes, the selections that you make for installation or removal cause conflicts. For example, a conflict occurs when you select two incompatible subsystems for installation, or when you select a subsystem for installation and do not select its prerequisites. When conflicts occur, the go command does not execute, and Inst posts a conflict advisory that suggests a resolution to the conflict.

When you see a conflicts advisory, you can either use the conflicts command to accept one of the suggested resolutions or use the install and remove commands to change your selections. You also see an advisory if your selections require more disk space than is safely available. This condition requires that you change your selections or remove software from the target system.

Ending a Session

To end an Inst session, enter the quit command. When you quit an installation session, Inst performs clean-up operations on target filesystems and on the newly installed software.