5.3 Selecting an Installation Approach

Since openMosix is a kernel extension, it won't work with just any kernel. At this time, you are limited to a relatively recent (at least version 2.4.17 or more recent) IA32-compatible Linux kernel. An IA64 port is also available. However, don't expect openMosix to be available for a new kernel the same day a new kernel is released. It takes time to develop patches for a kernel. Fortunately, your choice of Linux distributions is fairly broad. Among others, openMosix has been reported to work on Debian, Gentoo, Red Hat, and SuSe Linux. If you just want to play with it, you might consider Bootable Cluster CD (BCCD), Knoppix, or PlumpOS, three CD-bootable Linux distributions that include openMosix. You'll also need a reasonably fast network and a fair amount of swap space to run openMosix.

To build your openMosix cluster, you need to install an openMosix extended kernel on each of the nodes in the cluster. If you are using a suitable version of Linux and have no other special needs, you may be able to download a precompiled version of the kernel. This will significantly simplify setup. Otherwise, you'll need to obtain a clean copy of the kernel sources, apply the openMosix patches to the kernel source code, recompile the sources, and install the patched kernel. This isn't as difficult as it might sound, but it is certainly more involved than just installing a precompiled kernel. Recompiling the kernel is described in detail later in this chapter. We'll start with precompiled kernels.

While using a precompiled kernel is the easiest way to go, it has a few limitations. The documentation is a little weak with the precompiled kernels, so you won't know exactly what options have been compiled into the kernel without doing some digging. (However, the .config files are available via CVS and the options seem to be reasonable.) If you already have special needs that required recompiling your kernel, e.g., nonstandard hardware, don't expect those needs to go away.

You'll need to use the same version of the patched kernel on all your systems, so choose accordingly. This doesn't mean you must use the same kernel image. For example, you can use different compiles to support different hardware. But all your kernels should have the same version number.

The openMosix user tools should be downloaded when you download the openMosix kernel or kernel patches. Additionally, you will also want to download and install openMosixView, third-party tools for openMosix.