Chapter 5. Managing Storage

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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 to a 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 uppercase at that), and only traditional 8.3

file names (meaning an eight character file name, followed by a three character file extension).