Beowulf Software

The Beowulf software environment is implemented as an add-on to commercially available, royalty-free base Linux distributions. These distributions include all of the software needed for a networked workstation: the kernel, Linux utilities, the GNU software suite, and many add-on packages. Initially we used the very popular Slackware distribution. We have now migrated to the RedHat distribution with its better package management and upgrade system.

The Beowulf distribution includes several programming environments (all developed elsewhere) and development libraries as individually installable packages. PVM, MPI, and BSP are all available. SYS-V--style IPC and p-threads are also supported. A considerable amount of work has gone into improving the network subsystem of the kernel and implementing fast network device support. Most of these changes have been incorporated into the kernel source code tree, although many device driver updates are still in the active development or tuning phase.

In the Beowulf scheme, as is common in NOW clusters, every node is responsible for running its own copy of the kernel and nodes are generally sovereign and autonomous at the kernel level. However, in the interests of presenting a more uniform system image to both users and applications, we have extended the Linux kernel to allow a loose ensemble of nodes to participate in a number of global namespaces. A guiding principle of these extensions is to have little increase in the kernel size or complexity and, most importantly, negligible impact on the individual processor performance.