Chapter 1. Introduction

SGI SystemImager enables system administrators to easily replicate an entire Linux system onto a set of Linux machines, even when the machines have unformatted and unpartitioned disks. The user interface makes it easy to keep the hard drives of those systems synchronized after initial replication.

One machine in the set of Linux machines acts as a master (called the golden master). The golden master contains the image that will be replicated to the other machines in the set of Linux machines. The image of the golden master consists of a record of the golden master's partition information and a copy of all of the data on all of the golden master's locally mounted (that is, not NFS) ext2 filesystems. The machines that receive the image from the golden master are the clients. The clients receive the image through a server, which can be the same console that you log onto to run SystemImager or a separate machine. Figure 1-1 illustrates the SystemImager replication process in which the server and the console are the same machine. Figure 1-2 illustrates the SystemImager replication process in which the server and the console are different machines.

Figure 1-1. SystemImager server and console as the same machine

SystemImager server and console as the same machine

Figure 1-2. SystemImager server and console as different machines

SystemImager server and console as different machines

The server is the machine that holds the images and synchronizes the clients. You use the SystemImager tool to copy the golden master's hard drive image to the server. Then, you create a boot diskette for the client machines. This boot diskette can boot Linux, connect the client to the server, and copy the hard drive image onto the client machine.

With SystemImager, you can add clients, modify clients' parameters, or exclude clients from the list of machines that will be replicated. Once the client systems have had the initial image replicated to them, you can update any of them by making a change to the golden master and then resynchronizing the clients. As long as the changes to the golden master do not involve changing the partitioning information, resynchronization does not require the use of a boot diskette, and can be performed while the clients are up and running.

The SGI SystemImager tool is based on the VA SystemImager product. VA SystemImager is available freely as open source and available for download from the following site:

http://www.systemimager.org  

VA SystemImager is bundled with SGI SystemImager.

If you are a system administrator who manages mostly identical machines, you will find the SystemImager tool useful in any or all of the following situations: