Figure 1-14 TPC for Replication 1.6 File system general terminology Since SAN File System implements a SAN-based, global namespace file system, it is important here to understand some general file system concepts and terms. 1.6.1 What is a file system? A file system is a software component that builds a logical structure for storing files on storage devices (typically disk drives). File systems hide the underlying physical organization of the storage media and present abstractions such as files and directories, which are more easily understood by users. Chapter 1. Introduction 25