Book Review - Drupal 7 Multi-sites

A single instance of Drupal can be used to run more than one website. This means you can install the Drupal software once and have it drive more than one website - each with its own theme,content, and users. This feature is called multi-site hosting.

Multi-site technologies were developed as a response to the needs of system administrators and developers. But what are those reasons?
What problems are solved by multi-site configurations? There are many different reasons why people choose to host multiple sites on the same server. Here are several examples:
- Running different software on the same site
- Leveraging shared hosting
- Easing server administration
- Staging and testing a site before it is public
- Sharing a single code base for several sites
- Running secure (HTTPS) and standard (HTTP) sites on the same server
- Building an efficient development environment

Not all of these examples are best addressed with Drupal's multi-site feature, and Drupal isn't always the perfect solution for a multi-site challenge.

The Book Drupal 7 Multi-sites Configuration by Matt Butcher (Packt Publishing) gives insight to the setting up and administation of a Drupal multi-site.

Chapter 1 of this book introduces the broad concept of multi-site, discussing several ways that servers can be configured to run multiple sites. The first half of the chapter focuses on determining which sort of multi-site configuration is best for your needs. The second half focuses on setting up a server environment.

Chapter 2 shows how to install Drupal for Multi-site, and covers the process of installing Drupal once, and then configuring several sites to all run on this one Drupal instance. Multi-site configuration can be tricky, but this chapter will methodically walk you through the process. The chapter discusses :
- Downloading and installing the code
- Creating a default site
- Adding two additional sites

Chapter 3, focuses on adding features to multi-sites - such as modules, and themes. Sometimes features (provided by Drupal modules) are shared across sites, while other times only one of the sites will have a particular feature. This chapter discusses how this can be achieved.It also look at installing and configuring themes so that each site can have its own distinct look and feel. The following points are covered :
- Configuring each site separately
- Sharing configurations
- Installing shared modules
- Installing unshared (single-site) modules
- Installing themes and subthemes

Chapter 4, focuses on maintenance tasks especially regarding updating the multi-site Drupal installation. When running multiple sites on a single installation, it can sometimes be tricky to run software updates.While this is similar to the process used for a single site, there are some extra precautions and considerations. Performing updates in the proper order can prevent major multi-site outage. This chapter teaches you how to navigate the pitfalls of multi-site administration and specifically keeping Drupal up-to-date. The chapter looks at :
- Performing updates through the administrative web interface
- Updating Drupal's core in a multi-site configuration
- Updating modules and themes

Chapter 5 ,looks at various strategies for accomplishing advanced configurations.Rather than explaining the details of a module or two, this chapter addresses specific topics with general explanations and module suggestions. Each module discussed here comes with its own documentation on how it is used. These are the feature categories this chapter examines:
- Handling favicons and robots
- Sharing authentication across sites
- Sharing content across sites
- Sharing structural elements across sites
- Cross-site search

The book takes a practical hands-on approach, showing, by example, how to run several sites, each with its own theme, content, and users.