Installation Guide

Chapter 8. Customized BOS Installations

This chapter describes how to customize subsequent installations of the BOS after the operating system has been installed. Customizing an installation requires you to edit the bosinst.data file and use it with your installation media.

Introduction to Customized BOS Installations

The first time you install, the Base Operating System (BOS) installation program presents menus from which you must choose setup options. This initial installation also automatically starts a post-installation configuration program, either the graphical Configuration Assistant or the ASCII Installation Assistant. Refer to Chapter 3, Configuring the Operating System for more information about Configuration Assistant and Installation Assistant.

For subsequent installations, you can change many aspects of the default BOS install program by editing the bosinst.data file. For example, you can specify no prompts to install the BOS without menus. You can also customize a BOS installation to bypass Configuration Assistant or Installation Assistant and start your own configuration script. Also, the bosinst.data file can be used to replicate one set of installation settings on other machines. For example, system administrators can create a bosinst.data file with settings that can be used to install all the machines they support that have the same configuration. For AIX 4.3.3 and later versions of the operating system, you can use the Web-based System Manager Reinstall Base Operating System wizard to install systems from product or backup media. This application lets you customize your installation by answering prompts before installation and creates a bosinst.data file appropriate for the type of installation wanted.

If you run your own configuration script from a bosinst.data file or from the Network Installation Manager (NIM), the environment that is in place at the time the script is run is a single-user environment. This environment is not available as a multi-user environment, and thus, there are limits to what can be run from a configuration script. The /etc/init is not running, so no process management can take place. All available memory cannot be made available because the RAM file system still exists, so devices that require large amounts of memory to run might fail to configure. In addition, signal handling is not available.

Because of the single-user environment, use the following guidelines for configuration scripts:

Base devices can be configured, but devices that require daemons or more complex configuration should be started at reboot time by adding the necessary code to the end of the /etc/firstboot script.
Daemons should not be started.
Items such as NIS configuration, which uses system resource controller (SRC) commands, and so on, should be done by creating a separate entry in /etc/inittab and running a configuration script at reboot time.
No action should be taken that requires more than 32MB of paging space unless the paging space is implicitly increased.

Notes:

Another installation file, image.data, can also be modified and used during BOS installation. The image.data file contains information describing the root volume group image created during the BOS installation process. This information includes the sizes, names, maps, and mount points of logical volumes and file systems in the root volume group. The installation program also takes input from the image.data file regarding defaults for the machine being installed. See AIX 5L Version 5.1 Files Reference for a description of the image.data file. The procedure for using the bosinst.data file to customize BOS installation can also be used for the image.data file. The modified files can be used together to override BOS installation defaults.
You can also use the instructions in this chapter to create a supplemental diskette containing a modified preserve.list file, which is used during a Preservation Installation. For more information about a preservation installation, see Chapter 1, Installing the Base Operating System.

The bosinst.data file directs the actions of the BOS installation program. The file resides in the /var/adm/ras directory on the installed machine only, and it is not accessible on the commercial tape or the CD on which you received AIX 5.1.

The bosinst.data file contains stanzas with variables set to default values. Each variable is on a new line, in the Variable=Value form. A blank line separates each stanza. The information in these stanzas informs the installation program about such things as the method and type of installation, the disks in the machine, and the language used. By editing the file with an ASCII text editor, you can substitute new values for the default variables.

Customizing and Using a bosinst.data File

You must install the Base Operating System (BOS) before you can access and modify the default bosinst.data file. The Web-based System Manager Reinstall Base Operating System wizard can be used to prepare your next installation and in customizing the bosinst.data file. This file may also be retrieved and edited like any other ASCII file. If you are editing the bosinst.data file, use one of the following procedures:

Refer to Appendix B, bosinst.data File Stanza Descriptions and Appendix C, bosinst.data File Examples for information about the contents of the file and examples of edited files. You may verify the contents of your modified bosinst.data file by using the bicheck command.

If you are customizing the /bosinst.data file so that it becomes part of a system backup (mksysb), note that with AIX 4.3.3 and later, the mksysb command always updates the target_disk_data stanzas to reflect the current disks in the rootvg. If you do not want this update to occur you must create the file /save_bosinst.data_file. The existence of this file is checked by the mksysb command, before the target_disk_data stanzas are updated.

Create and Use a Backup Tape

To create and use a backup tape, use the following steps:

Customize the bosinst.data file:
1. Use the cd command to change your directory to the /var/adm/ras directory.
2. Copy the /var/adm/ras/bosinst.data file to a new name, such as bosinst.data.orig. This step preserves the original bosinst.data file.
3. Edit the bosinst.data file with an ASCII editor.
4. Verify the contents of the edited bosinst.data file using the bicheck command:
```
/usr/lpp/bosinst/bicheck filename
```
5. Copy the edited file to the root directory:
```
cp /var/adm/ras/bosinst.data /bosinst.data
```
6. If you do not want the target_disk_data file updated to reflect the current rootvg, create the file /save_bosinst.date_file by using the following command:
```
touch /save_bosinst.data_file
```
Create a backup image of the system using one of the following: the Web-based System Manager Backups application, SMIT, or mksysb command. Refer to Chapter 6, Creating System Backups for more information.
BOS installations from this backup behave according to your customized bosinst.data file.

Create and Use a Client File

Create one customized bosinst.data file for each client and, using the Network Installation Manager (NIM), define the files as NIM resources. Refer to AIX 5L Version 5.1 Network Installation Management Guide and Reference for more information about how to use the bosinst.data file as a resource in network installations.

Create and Use a Supplementary Diskette

Use this procedure to create the supplementary diskette and use it in future installations:

Customize the bosinst.data file:
1. Use the cd command to change your directory to the /var/adm/ras directory.
2. Copy the /var/adm/ras/bosinst.data file to a new name, such as bosinst.data.orig. This step preserves the original bosinst.data file.
3. Edit the bosinst.data file with an ASCII editor.
4. Create an ASCII file consisting of one word:
```
data
```
5. Save the new ASCII file, naming it signature.
Create the diskette and use it for installation:
1. Back up the edited bosinst.data file and the new signature file to diskette with the following command:
```
ls ./bosinst.data ./signature | backup -iqv
```
  OR
  If you create a bundle file named mybundle, back up the edited bosinst.data file, the new signature file, and the bundle file to diskette with the following command:
```
ls ./bosinst.data ./signature ./mybundle | backup -iqv
```
2. Put the diskette in the diskette drive of the target machine you are installing.
3. Boot the target machine from the installation media (tape, CD/DVD-ROM, or network) and install the operating system.
  The BOS installation program uses the diskette file, rather than the default bosinst.data file shipped with the installation media.