Solaris Flash (Overview and Planning)

This chapter provides an introduction to the Solaris Flash installation feature. Also included in the chapter is information necessary for planning a Solaris Flash installation in your environment.

• Solaris Flash Introduction

• Planning Your Solaris Flash Installation

Solaris Flash Introduction

The Solaris Flash installation feature enables you to use a single reference installation of the Solaris operating environment on a system, which is called the master system. Then, you can replicate that installation on a number of systems, which are called clone systems. You can replicate clone systems with a Solaris Flash initial installation that overwrites all files on the system or with a Solaris Flash update that only includes the differences from two system images. A differential update changes only the files that are specified and is restricted to systems that contain software consistent with the old master image.

Installing Clone Systems With an Initial Installation

You can install a master system with a Solaris Flash archive for an initial installation by using any installation method: Solaris Web Start, Solaris suninstall program, custom JumpStart, Solaris Live Upgrade or WAN boot. All files are overwritten. The Solaris Flash installation is a five-part process.

1. Install the master system. You select a system and use any of the Solaris installation methods to install the Solaris operating environment and any other software.

2. (Optional) Prepare customization scripts to reconfigure or customize the clone system before or after installation.

3. Create the Solaris Flash archive. The Solaris Flash archive contains a copy of all of the files on the master system, unless you excluded some nonessential files.

4. Install the Solaris Flash archive on clone systems. The master system and the clone system must have the same kernel architecture.

   When you install the Solaris Flash archive on a system, all of the files in the archive are copied to that system. The newly installed system now has the same installation configuration as the original master system, thus the system is called a clone system. Some customization is possible with the use of scripts.

5. (Optional) Save a copy of the master image. If you plan to create a differential archive, the master image must be available and identical to the image installed on the clone systems.

For step-by-step instructions, see Installing the Master System.

Figure 20-1 shows an installation of clone systems with an initial installation. All files are overwritten.

Figure 20-1 Solaris Flash Initial Installation

Updating Clone Systems With a Solaris Flash Differential Archive

If you have a clone system and want to update it, you can create a differential archive that contains only the differences between two images, the unchanged master image and an updated master image. When you update a clone system with a differential archive, only the files that are in the differential archive are changed. You can choose to install a Solaris Flash differential archive with the custom JumpStart installation method or Solaris Live Upgrade. An update is a five-part process.

1. Prepare the master system with changes. Before changes are made, the master system should be running a duplicate of the original archive.

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   Note - If the master system is not running a duplicate of the original archive, the differences between the two system images might result in a large differential archive. Consequently, installing the differential archive could be time consuming. Use an initial installation with a full archive in this case.

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2. (Optional) Prepare customization scripts to reconfigure or customize the clone system before or after installation.

3. Mount the directory of a copy of the saved-unchanged master image. This second image is to be used to compare the two system images. Access the image by the following methods.

   • Mounted from a Solaris Live Upgrade boot environment

   • Mounted from a clone system over NFS

   • Restored from backup using the ufsrestore command

4. Create the differential archive with the -A option of the flar create command.

5. Install the differential archive on clone systems with custom JumpStart. Or, you can use Solaris Live Upgrade to install the differential archive on an inactive boot environment.

Figure 20-2 shows the creation and installation of a differential archive. A master image is updated with some modifications. These modifications could be as simple as the addition, reconfiguration, or deletion of a few files, or as complex as propagating patches. The updated master image is compared to the unchanged master image. The differences between the two images become the differential archive. The archive can be used to update other clone systems that are currently using the unchanged master image. If the clone system has already been modified or is not running the unchanged master image, the update fails. If you have many changes to make on the clone systems, you can do an initial installation at any time.

Figure 20-2 Solaris Flash Update

Planning Your Solaris Flash Installation

Before you create and install a Solaris Flash archive, you must make some decisions about how you want to install the Solaris operating environment on your systems. The first time you install a system, you need to install with a full archive that is an initial installation. After a system has been installed with an archive, the system can be updated with a differential archive. The differential archive installs only the differences between two archives.

Designing an Initial Installation of the Master System

The first task in the Solaris Flash installation process is to install a system, the master system, with the configuration that you want each of the clone systems to have. You can use any of the Solaris installation methods to install an archive on the master system. The installation can be a subset or a complete installation of the Solaris operating environment. After you complete the installation, you can add or remove software or modify any configuration files.

The master system and the clone systems must have the same kernel architectures. For example, you can only use an archive that was created from a master system that has a sun4u architecture to install clones with a sun4u architecture.

You must install the master system with the exact configuration that you want on each of the clone systems. The decisions that you make when you design the installation of the master system depend on the following:

• The software that you want to install on the clone systems

• Peripheral devices that are connected to the master system and the clone systems

• The architecture of the master system and the clone systems

The software on the system can then be customized. See Customizing an Archive's Files and Directories. The master system can also be modified and set up for an update of a clone system. See Planning the Creation of a Solaris Flash Archive.

Customizing the Solaris Installation on the Master System

After you install the Solaris operating environment on the master system by using any of the Solaris installation methods, you can add or delete software and modify system configuration information as necessary.

• Delete software. You can remove software that you determine is not necessary to install on the clone systems. To see a list of software that is installed on the master system, use the Product Registry. For detailed instructions, refer to System Administration Guide: Basic Administration.

• Add software. You can install software that is included in the Solaris release. You can also add software that is not delivered as part of the Solaris operating environment. All of the software that you install on the master system is included in the Solaris Flash archive and is installed on the clone systems.

• Modify configuration files. You can alter configuration files on the master system. For example, you can modify the /etc/inet/inetd.conf file to restrict the daemons that the system runs. All of the modifications that you make are saved as part of the Solaris Flash archive and are installed on the clone systems.

Further customization can be done when creating the archive. For example, you can exclude large data files that you might not want in the archive. For an overview, see Customizing an Archive's Files and Directories.

To update a clone system, you can create a differential archive. See Planning the Creation of a Solaris Flash Archive.