 
 PIOUS for PVM 
PIOUS is a complete Parallel I/O System for the PVM 3 distributed computing
environment.  Just as PVM implements a virtual multicomputer on top
of a heterogeneous network of computing resources, PIOUS implements a fully
functional parallel file system on top of PVM.  PVM applications obtain
transparent access to shared permanent storage via PIOUS library functions.
PIOUS is intended to serve both as a platform for supporting high-performance
parallel applications, and as a vehicle for parallel file system research.
PIOUS implements the traditional functionality found in most parallel
computer file systems, as well as a number of unique features, including:
  -  two-dimensional file objects and logical file views,
  
-  coordinated file access with guaranteed consistency semantics,
  
-  data declustering for scalable performance,
  
-  transaction support and user-selectable fault tolerance modes,
  
-  extended file maintenance primitives for managing declustered files, and
  
-  C and Fortran language bindings.
PIOUS should work on most systems that support PVM 3.  To date, PIOUS has been
tested on the following:
Sun4/SunOS 4.1.3/5.3-4, SGI/IRIX 4.0.5/5.3, 
Dec Alpha/OSF1 2.1, HP 9000/HP-UX, and IBM RS6000/AIX.
Versions of PIOUS are installed at hundreds of sites, and the software
appears to be stable.
 PIOUS Source and Documentation 
The PIOUS documentation contains detailed installation information, as well
as a complete user's guide and reference manual.
The PIOUS software is distributed under the terms of the GNU Library General
Public License Version 2 (LGPL), as published by the Free Software Foundation,
and is provided
" as is "
without any warranty.  A copy of the LGPL is included
with the software distribution and details the terms of the license.
Note that the LGPL does allow proprietary applications to
make use of the PIOUS software.
 PIOUS Support and Bug Report 
The developers of PIOUS will provide support as time permits. Questions and
problems should be directed to
pious@mathcs.emory.edu. Please be as specific
as possible in any bug reports, and be sure to include machine type as well
as operating system, PVM, and PIOUS version numbers.
Any problems that are known to exist for a particular release are listed
in the
along with a workaround (if any) and the release
that corrects the problem.  This report will be updated as problems
are encountered and resolved.
It is highly recommended that this report be consulted
before installing PIOUS on your system.
For now, the usenet news group comp.parallel.pvm should be used as
an avenue for discussion about PIOUS.
 PIOUS Release History 
The following is a brief time-line of PIOUS releases, and the enhancements
provided by each:
  -  1.2.2 (05/95)
  
-  Data server scheduling algorithm updated to improve performance for
       conflicting accesses; previous scheduler bug corrected.
       
 Data server caching algorithm changed to Segmented LRU to limit
       the cache flooding caused by extended sequential access patterns.
-  1.2.1 (01/95)
  
-  Fortran language bindings added, along with the necessary updates
       to the documentation.
  
-  1.1.2 (12/94)
  
-  Initial system release.
 PIOUS Technical Reports 
The following PIOUS technical reports are available in postscript format:
  -  
       CSTR-950601: Characterizing Concurrency Control Performance for the
       PIOUS Parallel File System
  
-  Presents a detailed performance study of the PIOUS concurrency
       control mechanism.  Scalability and stability results are given
       for benchmark applications executed on Sandia's HEAT cluster.
       Subsumes CSTR-950202.
  
-  
       CSTR-950202: Scalable Concurrency Control for Parallel
       File Systems
  
-  Presents a detailed discussion of the scalable, light-weight concurrency
       control mechanism employed by PIOUS.  Preliminary performance results
       are given for a benchmark application executed on Sandia's
       high-performance HEAT cluster.
       
 Presented at the IOPADS workshop of the 1995 International
       Parallel Processing Symposium.
-  
       CSTR-941101: Parallel I/O as a Parallel Application 
  
-  Presents a complete overview of the PIOUS architecture and interface.
       Benchmark results are given for both standard and fault-tolerant
       file access in a low-performance cluster environment.
       Subsumes CSTR-940302 and CSTR-940101.
       
 Revised version to appear in the International Journal of
       Supercomputer Applications, 9(2), 1995.
-  
       CSTR-940302: PIOUS: A Scalable Parallel I/O System for
       Distributed Computing Environments 
  
-  Presents a brief overview of PIOUS.  Focuses on benchmark results
       for both standard and fault-tolerant file access in a
       low-performance cluster environment.
       
 Revised version appeared in the Proceedings of the Scalable
       High-Performance Computing Conference, 1994.
-  
       CSTR-940101: A Parallel I/O System for High-Performance Distributed
       Computing 
  
-  Presents a complete overview of the PIOUS architecture and
       interface.
       
 Revised version appeared in the Proceedings of the IFIP WG10.3
       Working Conference on Programming Environments for Massively
       Parallel Distributed Systems, 1994.
 PIOUS Developers 
 Other Sites of Interest 
PIOUS for PVM / Emory University / pious@mathcs.emory.edu