This chapter covers Linux filesystems from multiple viewpoints. I will discuss the structure of what is currently the most common Linux filesystems, EXT3 and EXT4, both logically and in the physical sense of how it is recorded on the hard drive. I will cover the care and maintenance of the EXT3/4 filesystem in detail. I will also briefly discuss other types of filesystems in use with Linux.

I will also discuss the Filesystem Hierarchy Standard and Logical Volume Management (LVM).

What is a Filesystem?

Filesystems have several functions with the ultimate objective of being able to provide a data storage medium for your computer.

  • Data Storage
  • Namespace
    • Naming and organizational methodology
  • API
    • System function calls to manipulate filesystem objects
  • Security model
    • Scheme for defining access rights
  • Implementation
    • Software to implement the above functions