The developers of FreeNAS have made available version 9.3.1. You can update it from within the GUI itself, or download the ISO here. Below are the release notes:
Release Notes for FreeNAS 9.3.1-RELEASE There are so many new features and enhancements in FreeNAS 9.3 that these release notes will break them into categories. In no particular order, FreeNAS 9.3.1-RELEASE (including this Software Update) offers the following improvements: [ Installation / Booting ] * FreeNAS now uses ZFS for the boot device(s), also supporting selection and mirroring of one or more boot devices for greater reliabilty. The features of ZFS are also utilized to provide cloned "boot environments" which allow the system to be rolled back (or even forked) to different OS versions. * A boot-time menu is provided for selecting and booting from a specific boot environment, a new system->boot UI allowing the user to create, rename, delete and select boot environments as well as running diagnostics on the boot pool and adding/replacing drives for it. * Both the installer and the installed system use the grub2 boot loader to provide boot menus and boot-time UI. * An install-time "Setup Wizard" is now provided to lead users who may be new to FreeNAS through the installation and setup process. Everything from the user's language, pool, shares, directory services, and initial settings can be set up through the Wizard. The Wizard is also careful to make no actual changes to the system until a final confirmation step, making it harmless to enter/exit the wizard at any time and simply explore its capabilities. * The ISO installation image can now be used both for USB booting or CD booting (the boot blocks allow for both usage scenarios), making a separate USB image unnecessary.