Planning For Disaster; Types Of Disasters; Hardware Failures - Red Hat ENTERPRISE LINUX 4 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

Planning for Disaster

Disaster planning is a subject that is easy for a system administrator to forget — it is not pleasant, and
it always seems that there is something else more pressing to do. However, letting disaster planning
slide is one of the worst things a system administrator can do.
Although it is often the dramatic disasters (such as a fire, flood, or storm) that first come to mind, the
more mundane problems (such as construction workers cutting cables or even an overflowing sink)
can be just as disruptive. Therefore, the definition of a disaster that a system administrator should keep
in mind is any unplanned event that disrupts the normal operation of the organization.
While it would be impossible to list all the different types of disasters that could strike, this section
examines the leading factors that are part of each type of disaster so that any possible exposure can be
examined not in terms of its likelihood, but in terms of the factors that could lead to disaster.

8.1. Types of Disasters

In general, there are four different factors that can trigger a disaster. These factors are:

Hardware failures

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Software failures
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Environmental failures
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Human errors
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8.1.1. Hardware Failures
Hardware failures are easy to understand — the hardware fails, and work grinds to a halt. What is more
difficult to understand is the nature of the failures and how your exposure to them can be minimized.
Here are some approaches that you can use:
8.1.1.1. Keeping Spare Hardware
At its simplest, exposure due to hardware failures can be reduced by having spare hardware available.
Of course, this approach assumes two things:
Someone on-site has the necessary skills to diagnose the problem, identify the failing hardware,
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and replace it.
A replacement for the failing hardware is available.
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These issues are covered in more detail in the following sections.
8.1.1.1.1. Having the Skills
Depending on your past experience and the hardware involved, having the necessary skills might be
a non-issue. However, if you have not worked with hardware before, you might consider looking into
local community colleges for introductory courses on PC repair. While such a course is not in and of
itself sufficient to prepare you for tackling problems with an enterprise-level server, it is a good way
to learn the basics (proper handling of tools and components, basic diagnostic procedures, and so on).
Chapter 8.