... h1. {anchor:GFWBW} Performing Multiple Installations with an Alternate Root
The Communications Suite installer allows multiple installations of the same product version on the same machine or Solaris zone by using different {{_INSTALLROOTS_}}. By using the {{altroot}} option of the {{commpkg install}} command, you can create multiple {{_INSTALLROOTS_}} on the same machine.
This document contains the following sections:
{toc:minLevel=2|maxLevel=2|location=top|type=list}
h2. Using Multiple Installations in a Side-by-Side Upgrade Scenario
The multiple-installation feature lets you perform side-by-side upgrades of some Communications Suite products.
In a side-by-side upgrade, the existing software on the host can continue to run while you install the new versions of the products on an alternate root on the same host. This approach minimizes downtime, so that end users can have continuous (or near-continuous) access to their email, calendars, and so on.
h4. Summary of Side-by-Side Upgrade Steps
In a side-by-side upgrade scenario, you perform the following tasks:
# Install the new Communications Suite software on the same host as the earlier versions. You can use the {{commpkg install}} commands shown in [To Install a Communications Suite Product in an Alternate Root|#altrootinstallsteps].\\
\\
# Configure the new software. Run the configuration script for the product.\\
\\
# Migrate data to the new directories under the alternate root's {{_INSTALLROOT_}}.\\
\\
# Configure alternate ports for the new installation under the alternate root. Alternatively, configure the host as a multi-home. For details, see [Running Multiple Installations of the Same Product on One Host - Conflicting Ports|#conflictingports].\\
\\
# Test the new software. \\
\\ |
... h2. {anchor:altrootinstallsteps} To Install a Communications Suite Product in an Alternate Root
Install the product in the alternate root with the {{—altroot}} option:\\
\\
# Install OS patches and Shared Components in the default {{_INSTALLROOT_}}. See [To Begin Installation|To Run the Communications Suite Installer].\\
\\
To install only the shared components, you can run {{commpkg install}} without {{\-\-altroot}} and select the product you want to install. You select a product by entering the number displayed next to it in the install list. Add a ~ (tilde) in front of the product number. \\
\\
For example, if you plan to install Messaging Server in the alternate root, you select {{~3}} during the default installation. This tells the installer to install the dependencies but not the product itself.\\
\\
{info:title=Note}
OS patches are always applied in the default {{INSTALLROOT}}, never in the alternate root.
{info}\\
\\
# Install the product in the {{altroot}}, as in the following example:\\
\\
{noformat}
commpkg install --altroot --installroot /opt/sun/comms2
{noformat} \\
\\
Be sure to use {{—installroot}} with {{—altroot}} to specify the alternate root.\\
\\
You can also avoid installing the shared components in the {{altroot}} by using the {{\-\-excludeSC}} option, as in the following example: \\
\\
{noformat}
commpkg install --excludeSC --altroot --installroot /opt/sun/comms2
{noformat} \\
\\
You may create as many alternate roots as you like. However, you should manually keep track of all the alternate roots you have created.
h2. Understanding _INSTALLROOT_ and Altroot
The following concepts define an {{altroot}}:
* An {{altroot}} is an alternate root directory.
* The {{altroot}} is used for multiple installations of Communications Suite products on the same host.
* The default root is the standard root directory, which can be indicated with a {{/}}.
* An {{altroot}} implies the existence of a default root.
The following concepts define an {{_INSTALLROOT_}}:
* An {{_INSTALLROOT_}} is the top-level installation path for the Communications Suite products and shared components.
* There is an {{_INSTALLROOT_}} (an installation path) for each instance of the installed products. That is, if your system has a default root and an {{altroot}}, the default root has one {{_INSTALLROOT_}}, and the {{altroot}} must have a different {{_INSTALLROOT_}}.
Now let's put them together:
* You _define_ an {{altroot}} by specifying its {{_INSTALLROOT_}} and using the {{\-\-altroot}} option with the {{commpkg install}} command.
h4. What's the Default?
If you use the default root and the default {{_INSTALLROOT_}}, the {{commpkg install}} command installs products under the following top-level directory:
{noformat}
/opt/sun/comms/
{noformat}
h4. An Example
Now suppose you want to install one instance of the products in {{/opt/sun/mycompany/comms/}}; and another instance of the same products in {{/opt/sun/mycompany/comms2/}}. You would use the following commands:
For the default root:
{noformat}
commpkg install --installroot /opt/sun/mycompany/comms/
{noformat}
For the {{altroot}}:
{noformat}
commpkg install --altroot --installroot /opt/sun/mycompany/comms2/
{noformat}
h2. {anchor:conflictingports} Running Multiple Installations of the Same Product on One Host: Conflicting Ports
By default, after you initially configure the product on alternate roots, the ports used by the different product installations are the same and thus conflict with each other.
This is not a problem if you install multiple installations of the same product on the same host but only intend to have one instance running at one time. For example, you may perform a side-by-side upgrade scenario in which you plan to stop the old instance before you start the new instance.
However, you may plan to test the new instance while the old instance is still running (and supporting end users). In this scenario, the ports are used simultaneously.
There are two ways to resolve this conflict:
* Configure individual ports
* Use a multi-home configuration
These approaches are described in the following sections.
h3. Configuring Individual Ports
See [Configuring Individual Ports for Multiple Installations of the Same Product|Configuring Individual Ports].
h3. Configuring a Host to Be Multi-Homed
See [Configuring a Host to be Multi-Homed|Configuring a Host to be Multi-Homed]. |