GEOM

GEOM is the main storage framework for the FreeBSD operating system. It is available in FreeBSD 5.0 and higher and provides a standardized way to access storage layers. GEOM is modular and allows for geom modules to connect to the framework. For example, the geom_mirror module will provide RAID1 or mirroring functionality to the system. A wide range of modules are already available, and new ones are always in active development by various FreeBSD developers.