<chapter id="flash-24"><title>Solaris Flash (Overview)</title><highlights><para>This book provides instructions for creating Solaris Flash archives
and using Solaris Flash archives to install the Solaris OS on multiple systems. </para><note><para>If you want an overview of all Solaris installation methods, see <olink targetdoc="solinstallpbiu" targetptr="planning-222" remap="external"><citetitle remap="section">Choosing a Solaris Installation Method</citetitle> in <citetitle remap="book">Solaris Express Installation Guide: Planning for Installation and Upgrade</citetitle></olink>. </para>
</note>
</highlights><sect1 id="flashoverview-2"><title>Solaris Flash Introduction</title><para>The Solaris Flash installation
feature enables you to use a single reference installation of the Solaris
OS 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 between 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.</para><sect2 id="flashoverview-36"><title>Installing Clone Systems With an Initial
Installation</title><para>You can install a master system with a Solaris Flash archive
for an initial installation by using any installation method: Solaris installation program,
custom JumpStart, Solaris Live Upgrade, or WAN boot. All files
are overwritten. The Solaris Flash installation is a five-part process.</para><orderedlist><listitem><para>Install the master system. You select a system and use any
of the Solaris installation methods to install the Solaris OS and any other
software.</para>
</listitem><listitem><para>(Optional) Prepare customization scripts to reconfigure or
customize the clone system before or after installation.</para>
</listitem><listitem><para>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.</para>
</listitem><listitem><para>Install the Solaris Flash archive on clone systems. The
master system and the clone system must have the same kernel architecture.</para><para>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:</para><itemizedlist><listitem><para>Scripts can be used for customization.</para>
</listitem><listitem><para>You can install extra packages with a Solaris Flash archive
by using the custom JumpStart installation method. The packages must be from
outside the software group being installed or a third-party package.</para>
</listitem>
</itemizedlist>
</listitem><listitem><para>(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.</para>
</listitem>
</orderedlist><para>For step-by-step instructions, see <olink targetptr="flashcreate-3" remap="internal">Installing
the Master System</olink>.</para><para><olink targetptr="flashoverview-fig-49" remap="internal">Figure 1&ndash;1</olink> shows
an installation of clone systems with an initial installation. All files are
overwritten.</para><figure id="flashoverview-fig-49"><title>Solaris Flash Initial Installation</title><mediaobject><imageobject><imagedata entityref="flash-initial"/>
</imageobject><textobject><simpara>The context describes the illustration.</simpara>
</textobject>
</mediaobject>
</figure>
</sect2><sect2 id="flashoverview-37"><title>Updating Clone Systems With a Solaris Flash Differential
Archive</title><para>If you have a clone system and want to update that system, 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.</para><orderedlist><listitem><para>Prepare the master system with changes. Before changes are
made, the master system should be running a duplicate of the original archive.</para><note><para>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.</para>
</note>
</listitem><listitem><para>(Optional) Prepare customization scripts to reconfigure or
customize the clone system before or after installation.</para>
</listitem><listitem><para>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.</para><itemizedlist><listitem><para>Mounted from a Solaris Live Upgrade boot environment</para>
</listitem><listitem><para>Mounted from a clone system over NFS</para>
</listitem><listitem><para>Restored from backup by using the <command>ufsrestore</command> command</para>
</listitem>
</itemizedlist>
</listitem><listitem><para>Create the differential archive with the <option>A</option> option
of the <command>flarcreate</command> command.</para>
</listitem><listitem><para>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.</para>
</listitem>
</orderedlist><para><olink targetptr="flashoverview-fig-50" remap="internal">Figure 1&ndash;2</olink> 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.</para><figure id="flashoverview-fig-50"><title>Solaris Flash Update</title><mediaobject><imageobject><imagedata entityref="flash-diff" width="100"/>
</imageobject><textobject><simpara>The context describes the illustration.</simpara>
</textobject>
</mediaobject>
</figure>
</sect2>
</sect1>
</chapter>