High Performance Linux Clusters with OSCAR, Rocks, OpenMosix, and MPI

Chapter 5. openMosix

openMosix is software that extends the Linux kernel so that processes can migrate transparently among the different machines within a cluster in order to more evenly distribute the workload. This chapter gives the basics of setting up and using an openMosix cluster. There is a lot more to openMosix than described here, but this should be enough to get you started and keep you running for a while unless you have some very special needs.

What Is openMosix?

Basically, the openMosix software includes both a set of kernel patches and support tools. The patches extend the kernel to provide support for moving processes among machines in the cluster. Typically, process migration is totally transparent to the user. However, by using the tools provided with openMosix, as well as third-party tools, you can control the migration of processes among machines.

Let’s look at how openMosix might be used to speed up a set of computationally expensive tasks. Suppose, for example, you have a dozen files to compress using a CPU-intensive program on a machine that isn’t part of an openMosix cluster. You could compress each file one at a time, waiting for one to finish before starting the next. Or you could run all the compressions simultaneously by starting each compression in a separate window or by running each compression in the background (ending each command line with an &). Of course, either way will take about the same amount of time and will load down your computer while ...