Setting up a cluster means setting up machines—hopefully, lots of machines. While you should begin with a very small number of machines as you figure out what you want, eventually you’ll get to the point where you are mindlessly installing system after system. Fortunately, most of those machines will have identical setups. You could simply repeat the process for each machine, but this will be both error prone and immensely boring. You need a way to automate the process.
The approach you need depends on the number of machines to be set up and configured, the variety of machines, how mission critical the cluster is, and your level of patience. For three or four machines, a manual install and configuration of each machine is a reasonable approach, particularly if you are working with an odd mix of different machines so that each setup is different. But even with a very small number of machines, the process will go more smoothly if you can automate some of the post-installation tasks such as copying configuration files.
Unless you have the patience of Job, with more than eight or ten machines in your cluster, you’ll want to automate as much of the process as possible. And as your cluster’s continuous operation becomes more crucial, the need for an automated approach becomes even more important.
This chapter begins with a quick look at simple approaches to ease configuring multiple systems after the operating system has been installed. These techniques are ...