The concept of a BE is central to the operation and implementation of LU. A BE is a group of file systems and their associated mount points. LU uses the term “boot environment” instead of “boot disk” because a BE can be contained on one disk or can be spread over several disks. LU provides a command-line interface and a graphical user interface (GUI) to create, populate, manipulate, and activate BEs.
You can create BEs on separate disks or on the same disk; however, a single root (/) file system is the recommended layout for the Solaris OE.
The active BE is the one that is currently booted and active; all other defined BEs are considered inactive. Inactive BEs are also referred to as alternate boot environments (ABEs).