The preinstalled Oracle Solaris OS is installed on a ZFS file system, as described in Preinstalled Software.
Table 1-1 Preinstalled Software
Note - Refer to the Customer Information Sheet shipped with your server to identify which version of Oracle Solaris OS is preinstalled.
Note - In addition to reading the product notes for your server, always review the latest version of the Oracle Solaris OS release notes when installing or using the server. The release notes provide important installation, runtime, and update information that you should consider when installing or running the Oracle Solaris OS. The release notes also list the known OS problems and provide workarounds when available.
Find the release notes for your version of the OS on the following web site: http://docs.oracle.com