Abstract: A parallel virtual file system for parallel processing systems including single-processor systems having multiple storage devices.

Abstract: Two methods for partitioning the work to be done by a computer program into smaller pieces so that checkpoints may be done more frequently. Initially, a parallel task starts with one or more input data sets having q initial partitions, divides the input data sets into p partitions by some combination of partitioning elements (i.e., partitioners/gatherers), runs an instance of a component program on each of the p partitions of the data, and produces one or more sets of output files, with each set being considered a partitioned data set. The invention is applied to such a task to create a new, "overpartitioned" task as follows: (1) the partitioner is replaced with an "overpartitioner" which divides its q inputs into n*p partitions, for some integer factor n; (2) the component program is run in a series of n execution phases, with p instances of the component program being run at any time.

Abstract: Methods and systems for running and checkpointing parallel and distributed applications which does not require modification to the programs used in the system nor changes to the underlying operating system. One embodiment of the invention includes the following general steps: (1) starting an application on a parallel processing system; (2) controlling processes for the application, including recording of commands and responses; (3) controlling a commit protocol; (4) detecting failures of the application; (5) continuing execution of the application from the most recently committed transaction after "replaying" the recorded commands and responses.