I was recently asked to help a customer in their deployment efforts of a SPARC SuperCluster environment for Oracle applications. The question was "How can we configure a different size for a swap device when provisioning Solaris 11?". The answer was clearly "through the Automated Installer (AI) manifest", but exactly what needed to be changed was something that required proper syntax. Looking at the AI manifest that's configured on the existing install service (via: installadm export ...) does allow you to dump the existing AI manifest into a file for further manipulation. The goal is to determine exactly what bits need to be inserted, and where, and then run a combination of installadm update-manifest ... to populate the contents of the AI install service with the contents of the manipulated file.
Here is the bolded <zvol> syntax that needs to be inserted into the AI manifest file, that configures the swap size of 48GB on a newly installed system. It needs to go in the section before the boot environments are defined.
<zpool name="rpool" is_root="true">
<filesystem name="export" mountpoint="/export"/>
<zvol name="swap" action="create" use="swap">
<size val="48gb" />
You can get more details on the overall process of updating AI services with installadm in this How-To document