Certification Objective 15.03Understanding and Using the Flash Archive

Certification Objective 15.03—Understanding and Using the Flash Archive

Exam Objective 6.6: Explain flash, create and manipulate the flash archive, and use it for installation.

The Solaris flash archive, one of several available installation methods, is used to replicate a single reference installation on multiple machines. The replicas are called clones. From a given reference installation, you can create a replica (clone) in one of the following ways:

• Solaris flash initial installation. Overwrites all existing files on the system.

• Solaris flash update. Includes only the difference between two system images—the flash image and the image of the existing system.

• Differential update. Changes only the specified files.

Before we dive into the details, it's important to understand the basic concepts and the processes involved in the flash archive installation method.

Understanding the Flash Archive

Understand that flash archive is not a full-fledged new installation method independent of other methods. It is rather a different source of installation—an image of an already installed system, called flash archive. Once you have a flash archive, it can be installed by using methods you are already familiar with and fall into two broad categories: initial installation or upgrade. If you are using the initial installation, it could be any of the following: Solaris installation program, custom JumpStart, or WAN boot. The initial installation, called Solaris flash initial installation in this case, involves the following five steps:

1. Install the reference system, called the master system, by using any of the Solaris installation methods.

2. Prepare scripts to customize (or reconfigure) a clone system after or before installation.

3. Create a copy of the master system, called a flash archive. You can exclude some files that are not needed. This is the image that you will use for making clones.

4. Create a clone system by installing the flash archive on a machine. The machine with the clone system must have the same architecture as the machine with the master system.

5. Save a copy of the master image as protection against losing the master because of a system failure.

Obviously steps 2 and 5 are optional. You can create the master system by using any installation method that we have already discussed in this chapter and in Chapter 2. But how do you create the flash archive?

Creating a Flash Archive

As a system administrator, you will need to manage the flash archives, which include creating a flash archive from a master system, splitting an archive into different sections, combining different sections of an archive into one archive, and retrieving information about the archive. All these tasks can be accomplished by using the flar command with different subcommands such as create to create an archive, as shown in Table 15-2.

Table 15-2: Different subcommands that can be used with the flar command

Command	Description
flar create or flarcreate	Creates a flash archive from a master system
flar combine	Combines the different archive sections in different files into one archive.
flar info	Provides information about an archive
flar split	Splits an archive into sections with each section in a separate file.

To create the flash archive for a master system, you should boot the master system and run it in the most inactive state possible. The first preference is to run the system in single-user mode. If this is not possible, you must at least shut down the applications that you want to include in the archive and the applications that are using extensive OS resources.

You can create a Solaris flash archive when the master system is in one of the following states:

1. Master system running in single-user mode.

2. Master system running in multiuser mode.

3. Master system booted from one of the following:

   • Solaris 10 Software-1 CD

   • Solaris 10 Operating System DVD

   • An image of the Solaris 10 software

To create the archive from any of these sources, issue the flar command with the create subcommand, which has the following syntax:

    flar create -n <archiveName> [<otherOptions>] <path>/<fileName> 

The -n option is mandatory, where the argument <archiveName> specifies the name that you give to the archive. The <fileName> specifies the name of the archive file, and <path> specifies the full path of the directory in which the archive file resides. If you do not specify the path, the archive file will be saved in the current directory. Some other options that you can use with this command are described here:

• -a <authorName>. Specifies an author name for the archive identification section.

• -e <desc>. Specifies the description to be included in the archive as the value of the content_description identification key.

• -i <date>. Specifies the date to be included in the archive as the value of the creation_date field in the identification section. By default (that is, in the absence of this option), the current system date is included.

• -c. Compresses the archive by using the compress command.

• -m <masterName> Specifies the name of the master system to be used as the value of the creation_master field in the identification section of the archive. By default, the name of the system on which the flar create command is issued is used as the value of this field.

• -R <root>. Specifies the root directory for the directory subtree to be archived. The default root is the system root (/).

• -S. Specifics to skip the disk space check and to keep the archive in memory. Without this option, the create command builds a compressed archive in memory, and checks the disk space before writing the archive to the disk.

• -x <excludeDirFile>. Exclude from the archive those files and directories whose names are specified by <excludeDirFile> on the command line.

• -X <excludeList>. Exclude from the archive those files and directories whose names are listed in the file the name of which is specified by <excludeList>. The list in the file should contain one name (file or directory) per line.

• -y <includeDirPile>. Includes in the archive those files and directories whose names are specified by <includeDirFile> on the command line.

Once you have a flash archive, you can check what is in the archive by issuing the following command:

    flar info -l <fileName> 

The argument <fileName> specifies the name of the archive file. The command displays the file structure of the archive.

Now that you know how to create and manipulate a flash archive, here are some practical scenarios and solutions:

SCENARIO & SOLUTION
Create an exact copy of a master system, compress it, and store it in a file named archive_exact.flar. Name the archive: archive_exact.	flar create -n archive_exact -c archive_exact.flar
Display the file structure of the archive.	flar info -l archive_exact. flar
Create a flash archive from a master system and exclude all the content under the /test directory except the content in the /test/scripts directory. Name the archive as archive_in and the archive file archive_in.flar.	flar create -n archive archive_in -x /test -y /test/scripts archive_in.fl

Installing a Solaris Flash Archive

You can install a Solaris flash archive by using any of the methods that you already know: Solaris installation program, custom JumpStart, Solaris Live Upgrade, or WAN boot. To use the Solaris installation program to install a Solaris flash archive, perform the following procedure:

1. Begin the Solaris installation program and proceed through the steps described in Chapter 2.

2. When you reach the Specify Media panel, continue with the Solaris flash installation.

3. Specify the media you are using to install:

   1. Give the feedback that you are prompted for, depending on the selected media:

      1. DVD or CD. Insert the disk that contains the Solaris flash archive.

      2. Network File System. Specify the path to the archive on the NFS.

      3. HTTP. Specify the URL and the proxy information that is needed to access the archive.

      4. FTP. Specify the FTP server and the path to the flash archive on it.

      5. Local tape. Specify the local tape device and the path to the flash archive on it.

   2. For flash archives stored on a disk or an NFS server, respond to the Select Flash Archives panel by selecting one or more archives to install.

   3. On the Flash Archives Summary panel, confirm the selected archives and click Next.

      The Additional Flash Archives panel is displayed. If you want to install an additional Solaris flash archive, specify the media on which the other archive is located. If you have no other archive to install at this time, select None.

4. Click Next and follow the steps for completing the installation.

What we have described is an initial installation that will overwrite everything on the system disk.

A Solaris flash archive provides you with choices in the source of installation—instead of installing the original Solaris installation software, you install the image of an already installed system. This offers a quick and robust way of installing a large number of identical systems. You can quickly clone an installed system.

Before you can install an operating system on a machine, the machine must start booting. A machine can boot either by using a local medium or over the network.