File Systems - Red Hat ENTERPRISE LINUX 4 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

Chapter 5. Managing Storage
5.5.1.1.2.2. Extended Partitions
Extended partitions were developed in response to the need for more than four partitions per disk drive.
An extended partition can itself contain multiple partitions, greatly extending the number of partitions
possible on a single drive. The introduction of extended partitions was driven by the ever-increasing
capacities of new disk drives.
5.5.1.1.2.3. Logical Partitions
Logical partitions are those partitions contained within an extended partition; in terms of use they are
no different than a non-extended primary partition.
5.5.1.1.3. Partition Type Field
Each partition has a type field that contains a code indicating the partition's anticipated usage. The
type field may or may not reflect the computer's operating system. Instead, it may reflect how data is
to be stored within the partition. The following section contains more information on this important
point.

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 com-
puter 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.
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