A filesystem is nothing but the data structures that an operating system uses to keep track of files on a disk. The filesystem stores your pictures, music, videos, accounting data and more. The different operating system comes with various filesystems. You may need to move data between FreeBSD and other Unix-like systems like OS X or Linux based device. Knowing all about filesystem help us to archive or move data between system. The “FreeBSD Mastery: Specialty Filesystem” is an essential, practical and well-written book.