Introduction

When you come right down to it, the most important responsibility of network administrators is to ensure data availability. When users, customers, or clients need access to network data, it should be ready to go. Many organizations depend on data availability; without it, they could not function.

Two key strategies help ensure data availability: fault tolerance and disaster recovery. In order to fulfill the role of network administrator, is it essential that you have a clear understanding of how to use these strategies.

In addition to fault tolerance and disaster recovery, two additional objectives covered in this chapter have to do with network attached storage (NAS) and virtual local area networks (VLANs). NAS is becoming increasingly popular in modern network environments. It provides a means to offload data storage from server systems and onto dedicated storage devices that are connected directly to the network. VLANs, on the other hand, are used to segment a network for the purposes of organization and security.

It might seem unusual to include VLANs and network storage in a chapter about fault tolerance and disaster recovery because the topics do not appear to be related. However, we need to stick to the CompTIA objectives as closely as possible to make it as easy as possible for you to find exam information. The downside of this approach is that the objectives do not always follow a logical order.