In this chapter
In previous chapters, we've taken a look at networking hardware and cabling as well as the hardware and software used for network servers and clients . We've also looked at issues related to serving up a Web site. An important aspect of managing a network, and something that we definitely need to discuss, is how you protect the important data on the network.
Now, I'm not talking about network security issues here, such as strategies for keeping intruders from hacking into your network (these are discussed in Chapter 20, "A Network Security Primer"). I'm talking about strategies that allow you to protect data in situations where a file server's hard drive fails or an employee accidentally erases an important database file. In this chapter, we will look at strategies that add redundancy to a network. This redundancy can take many forms. It can be a backup of all the important files on the network, or it can be a set of redundant disk drives that contain exactly the same information.
Making sure important computers such as file servers keep running, even during a power failure (at least until you can shut them down correctly), is another issue related to protecting data on the network. The main issue we will look at here is building fault tolerance into a LAN, which is a fancy way of saying we don't want to lose any data, no matter what happens to our servers and other network devices.
Let's begin our discussion with a look at the different data-protection schemes that use redundant disk drives. We'll then take a look at issues related to backing up data on a network, and then we can explore the use of uninterruptible power supplies .