The openMosix Linux kernel extension turns networked computers into a SSI cluster. The openMosix Project is both Open Source and Open Project. The open nature of our project brings good ideas and contributions from our users. We share our plans, accept code contributions, and value outside suggestions. This openness accelerates the project development. Our port to IA-64 Linux has begun and will create a native High Performance Computing (HPC) platform for the IA-64.

openMosix is installed on each participating node of a LAN. Since all openMosix extensions are inside the kernel, applications automatically and transparently benefit from this distributed computing concept. There is no need to program those applications specifically for openMosix. The cluster behaves much as does a Symmetric Multi-Processor (SMP), but this solution scales to well over a thousand nodes which can each be SMPs. Once installed and booted, the openMosix nodes see each other in the cluster and start exchanging information about their load level and resource usage. Processes originating from any one node, if that node is too busy compared to others, can migrate to any other node, repeatedly, during their lives. openMosix continuously attempts to optimize the resource allocation.

The remainder of this paper discusses how this is done, what applications benefit the most and least, and what enhancements are planned to increase the number and type of applications that benefit.

Moshe Bar is an operating systems kernel programmer, writer of Byte Magazine column Serving With Linux, author of numerous Linux books and university teacher. Next to that he is also the Chief Technical Officer of Qlusters, Inc., and is the Project Manager for openMosix.