Managing Physical Folios of Objects Between Nodes

With modern operating systems, it is becoming easier to implement single level stores using memory management techniques to manage memory pages or slot segments between virtual memory and local disk. In this paper, we describe the ptool management system, which, in addition, gathers physical collections of segments into UNIX files we call folios. Ptool can cache and migrate folios from a hierarchical storage system, between nodes in a high performance cluster, or between nodes in a wide area network. We describe our experience to date using ptool for the analysis of high energy physics data, aeronautics data, and financial data.