How to build a fast and reliable 1024 node cluster with only one disk

In the last year LANL has constructed a 1408-node AMD Opteron cluster, a 1024-node Intel P4 Xeon cluster, a 256-node AMD Opteron cluster and two 128-node Intel P4 Xeon clusters. Each of these clusters is controlled by one front-end node, and each cluster needs only one disk in the front-end node for production operations. In this paper we describe the software architecture that boots and manages these clusters. This software architecture represents a clean break from the way that clusters have been set up for the last 14 years. We show the ways that this architecture has been used to greatly improve the operation of the nodes, with particular emphasis on improvements in boot-time performance, scalability, and reliability.