5.5.2. File Systems

Even with the proper mass storage device, properly configured, and appropriately partitioned, we would still be unable to store and retrieve information easily -- we are missing a way of structuring and organizing that information. What we need is a file system.
The concept of a file system is so fundamental to the use of mass storage devices that the average computer user often does not even make the distinction between the two. However, system administrators cannot afford to ignore file systems and their impact on day-to-day work.
A file system is a method of representing data on a mass storage device. File systems usually include the following features:
  • File-based data storage
  • Hierarchical directory (sometimes known as "folder") structure
  • Tracking of file creation, access, and modification times
  • Some level of control over the type of access allowed for a specific file
  • Some concept of file ownership
  • Accounting of space utilized
Not all file systems posses every one of these features. For example, a file system constructed for a single-user operating system could easily use a more simplified method of access control and could conceivably do away with support for file ownership altogether.
One point to keep in mind is that the file system used can have a large impact on the nature of your daily workload. By ensuring that the file system you use in your organization closely matches your organization's functional requirements, you can ensure that not only is the file system up to the task, but that it is more easily and efficiently maintainable.
With this in mind, the following sections explore these features in more detail.

5.5.2.1. File-Based Storage

While file systems that use the file metaphor for data storage are so nearly universal as to be considered a given, there are still some aspects that should be considered here.
First is to be aware of any restrictions on file names. For instance, what characters are permitted in a file name? What is the maximum file name length? These questions are important, as it dictates those file names that can be used and those that cannot. Older operating systems with more primitive file systems often allowed only alphanumeric characters (and only uppercase at that), and only traditional 8.3 file names (meaning an eight-character file name, followed by a three-character file extension).