FreeNAS provides a built-in update manager, allowing the administrator to install a specific release that contains system patches or new features. When the system is updated, a copy of the current system is retained in the boot menu, making it easy to revert to the previous version should the need arise.

To upgrade to FreeNAS Corral from FreeNAS 9.10, select FreeNAS-Corral-STABLE from the trains drop-down menu of the System -> Update screen. The upgrade process will migrate the 9.10 configuration into the FreeNAS Corral configuration format. Once the system has been upgraded, you can revert the system to FreeNAS 9.10 by rebooting and selecting that entry in the boot menu. Note that a FreeNAS Corral configuration is different from a FreeNAS 9.10 configuration. This means that you should not attempt to restore a configuration that was saved on FreeNAS 9.10 to FreeNAS Corral and vice versa. If you are using an earlier version of FreeNAS, you should either first upgrade to FreeNAS 9.10 and verify the configuration, or do a fresh install of FreeNAS Corral and recreate the configuration.