PVM_INTRO(1PVM) 						  PVM Version 3.4						   PVM_INTRO(1PVM)

NAME

       PVM, pvm_intro - Parallel Virtual Machine System Version 3

DESCRIPTION

       PVM  is	a  software  system that enables a collection of heterogeneous computers to be used as a coherent and flexible concurrent computa-
       tional resource.

       The individual computers may be shared- or local-memory multiprocessors, vector supercomputers, specialized  graphics  engines,	or  scalar
       workstations, that may be interconnected by a variety of networks, such as ethernet, FDDI.

       User programs written in C, C++ or Fortran access PVM through library routines (libpvm3.a and libfpvm3.a).

       Daemon programs (pvmd3) provide communication and process control between computers.

MACHINE ARCHITECTURE

       In the PVM system, machines are assigned a short string to identify their architectures (this includes operating system type as well as CPU
       type).  The types currently predefined in the distribution are:
	      AFX8	    Alliant FX/8
	      ALPHA	    DEC Alpha/OSF-1
	      ALPHAMP	    DEC Alpha/OSF-1 / using shared memory
	      AIX46K	    IBM/RS6000 / AIX 4.x
	      AIX4MP	    IBM SMP / shared memory transport / AIX 4.x
	      AIX4SP2	    IBM SP-2 / using MPI / AIX 4.x
	      APOLLO	    HP 300 running Domain/OS
	      ATT	    AT&T/NCR 3600 running SysVR4
	      BAL	    Sequent Balance
	      BFLY	    BBN Butterfly TC2000
	      BSD386	    80[345]86 running BSDI or BSD386
	      CM2	    Thinking Machines CM-2 Sun front-end
	      CM5	    Thinking Machines CM-5
	      CNVX	    Convex using IEEE floating-point
	      CNVXN	    Convex using native f.p.
	      CRAY	    Cray
	      CRAY2	    Cray-2
	      CRAYSMP	    Cray S-MP
	      CSPP	    Convex Exemplar
	      CYGWIN	    POSIX emulation layer on top of Windows32
	      DGAV,DGIX     Data General Aviion
	      E88K	    Encore 88000
	      FREEBSD	    80[345]86 running FreeBSD
	      HP300	    HP 9000 68000 cpu
	      HPPA	    HP 9000 PA-Risc
	      HPPAMP	    HP 9000 PA-Risc / shared memory transport
	      KSR1	    Kendall Square
	      I860	    Intel RX Hypercube
	      IPSC2	    Intel IPSC/2
	      LINUX	    80[345]86 running Linux
	      LINUXALPHA    DEC Alpha running Linux
	      LINUXARM	    Strogarm running Linux
	      LINUXHPPA     HP 9000 running Linux
	      LINUXPPC	    PowerPC running Linux
	      LINUXSPARC    Sparc running Linux
	      M88K	    Motorola M88100 running Real/IX
	      M88K	    Motorola M88100 running Real/IX
	      MASPAR	    Maspar
	      MIPS	    Mips
	      NETBSDALPHA   DEC Alpha running NetBSD
	      NETBSDAMIGA   Amiga running NetBSD
	      NETBSDARM32   Strongarm running NetBSD
	      NETBSDHP300   HP 300 running NetBSD
	      NETBSDI386    80[345]86 running NetBSD
	      NETBSDM68K    Any Motorola 68K running NetBSD
	      NETBSDMAC68K  Macintosh running NetBSD
	      NETBSDMIPSEB  Mips EB running NetBSD
	      NETBSDMIPSEL  Mips EL running NetBSD
	      NETBSDNS32K   NS32K running NetBSD
	      NETBSDPMAX    DEC Pmax running NetBSD
	      NETBSDPOWERPC PowerPC running NetBSD
	      NETBSDSH3     SH3 running NetBSD
	      NETBSDSPARC   Sparc running NetBSD
	      NETBSDSPARC64 Sparc64 running NetBSD
	      NETBSDSUN3    SUN 3 running NetBSD
	      NETBSDVAX     Vax running NetBSD
	      NEXT	    NeXT
	      OS2	    OS/2
	      PGON	    Intel Paragon
	      PMAX	    DEC/Mips arch (3100, 5000, etc.)
	      RS6K	    IBM/RS6000 / AIX 3.x
	      RS6KMP	    IBM SMP / shared memory transport / AIX 3.x
	      RT	    IBM/RT
	      SCO	    80[345]86 running SCO Unix
	      SGI	    Silicon Graphics IRIS
	      SGI5	    Silicon Graphics IRIS running OS 5.0
	      SGI6	    Silicon Graphics IRIS running OS >= 6.0
	      SGI64	    Silicon Graphics IRIS running 64 bit
	      SGIMP	    Silicon Graphics IRIS / OS 5.x / using shared memory
	      SGIMP6	    Silicon Graphics IRIS / OS 6.x / using shared memory
	      SGIMP64	    Silicon Graphics IRIS / 64 bit / using shared memory
	      SP2MPI	    IBM SP-2 / using MPI / AIX 3.x
	      SUN3	    Sun 3
	      SUN4	    Sun 4, 4c, sparc, etc.
	      SUN4SOL2	    Sun 4 running Solaris 2.x
	      SUNMP	    Sun 4 / using shared memory / Solaris 2.x
	      SX3	    NEC SX-3
	      SYMM	    Sequent Symmetry
	      TITN	    Stardent Titan
	      U370	    IBM 3090 running AIX
	      UTS2	    Amdahl running UTS
	      UVAX	    DEC/Microvax
	      UWARE	    Uware
	      UXPM	    Fujitsu running UXP/M
	      VCM2	    Thinking Machines CM-2 Vax front-end
	      WIN32	    Windows 95/98/NT
	      X86SOL2	    80[345]86 running Solaris 2.x

ENVIRONMENT VARIABLES

       The following environment variables are read by PVM and may be set in order to customize your PVM environment.  To set them,  you  can  add
       commands  to  your .cshrc or .profile or equivalent shell startup file.	See the manual page for the shell you normally use for information
       about how to do this.  You can also include an appropriate shell startup file stub to set PVM environment variables and to add PVM directo-
       ries  to  your  execution path.	Inert the matching stub file, pvm3/lib/cshrc.stub, pvm3/lib/kshrc.stub or pvm3/lib/bashrc.stub, after your
       declaration of PVM_ROOT in your shell startup file.

       For csh users: Note that setting them in .login does not have the same effect.  The .login script file is only read when you  are  actually
       logging	in, whereas .cshrc is read every time csh starts up.  PVM needs to have environment variables set when it starts a slave pvmd with
       "rsh host pvmd ...", so they must be set in .cshrc.

       For those using a shell that doesn't always read a startup script (e.g. sh, ksh), there is another way to  set  environment  variables  for
       PVM.  Before running the PVM executables, the pvm and pvmd startup scripts source any commands in $HOME/.pvmprofile if this file exists.

       The following environment variables are supported by PVM 3.4.4:

       PVM_ROOT
	      The  path  where	PVM libraries and system programs are installed, for example /usr/local/pvm3 or $HOME/pvm3.  This variable must be
	      set on each host where PVM is used in order for PVM to function.	There is no default value.

       PVM_TMP
	      The path for PVM temporary files, such as the daemon socket file pvmd.<uid> and the log file pvml.<uid>.	Use this environment vari-
	      able  to	use a directory other than /tmp (or C:TEMP on Win32), or to introduce added security by using a protected subdirectory in
	      /tmp that is owned by your userid and cannot be easily corrupted.

       PVM_RSH
	      The path to the "rsh" program on your system, if different than that defined in the $PVM_ROOT/conf/$PVM_ARCH.def configuration file.
	      This environment variable can also be used to replace "rsh" with "ssh" for added security.

       PVM_PATH
	      The  execution  path  to	be  searched  for  PVM	programs  on  your  system.  By default, PVM looks in $HOME/pvm3/bin/$PVM_ARCH and
	      $PVM_ROOT/bin/$PVM_ARCH for your PVM applications.  This environment variable does not override the ep= host file option.

       PVM_WD The working directory for spawned PVM programs on your system.  By default, PVM spawns your PVM applications in $HOME, but for  con-
	      venience in accessing data or input files using relative path names, an alternate working directory can be specified.  This environ-
	      ment variable does not override the wd= host file option.

       PVM_EXPORT
	      Names of environment variables to export from a parent task to children tasks through pvm_spawn().  Multiple names must be separated
	      by ':'.  If PVM_EXPORT is not set, no environment is exported.

       PVM_DEBUGGER
	      The debugger script to use when pvm_spawn() is called with PvmTaskDebug set.  The default is $PVM_ROOT/lib/debugger.

       PVM_DPATH
	      The path of the pvmd startup script (default is $PVM_ROOT/lib/pvmd).  It is overridden by host file option dx=.

	      This  variable  is  useful  if you use a shell that doesn't automatically execute a startup script (such as .cshrc) to allow setting
	      PVM_ROOT on slave (added) hosts.	If you set it to  the  absolute  or  relative  path  of  the  pvmd  startup  script  (for  example
	      /usr/local/pvm3/lib/pvmd or pvm3/lib/pvmd), the script will automatically set PVM_ROOT.  Note that for this to work, you must set it
	      to run the pvmd script, not the pvmd3 executable itself.

       PVM_WINDPATH
	      This variable serves the same purpose as the PVM_DPATH above, but specifically for Win32 systems.  This second environment  variable
	      allows  for  alternate specification of the path to the pvmd3.exe daemon executable using appropriate DOS file path syntax and envi-
	      ronment variables (e.g. %PVM_ROOT%libWIN32pvmd3.exe).

       PVMHOSTFILE
	      Specifies the path to an optional host file to be used by default when starting PVM.  This alleviates the need to  manually  pass  a
	      host file path argument to the "pvm" console or "pvmd" script when starting PVM.

       PVMDLOGMAX
	      Sets the maximum length of the pvmd error log file.  Default value is the PVMDLOGMAX parameter in the source, 1 Mbyte.

       PVMDDEBUG
	      Sets  the  default  pvmd debugging mask (as does the pvmd -d option).  Value can be in hexadecimal (0x...), octal (0...) or decimal.
	      Used to debug the pvmd (not intended to be used to debug application programs).

       PVMTASKDEBUG
	      Sets the default libpvm debugging mask (as does pvm_setopt(PvmDebugMask, x)).  Value can be in hexadecimal (0x...), octal (0...)	or
	      decimal.	Used to debug libpvm (not intended to be used to debug application programs).

       PVMTASK
	      Sets  additional	flag  bits  for  the pvm_spawn() library call.	Allows override at run time of flags compiled into the pvm_spawn()
	      calls in PVM application, e.g. to turn on PvmTaskDebug for popping up child tasks in a debugger window.

       PVMBUFSIZE
	      Sets the size of the shared memory buffers used by libpvm and the pvmd.  The default value is 1048576.   If  your  program  composes
	      messages longer than this size, you must increase it.

       PVM_VMID
	      A  new feature in PVM 3.4.4 is the concept of a "Virtual Machine ID".  You can now set the PVM_VMID environment variable to an arbi-
	      trary string (or use the "id=" option in a host file, see man page for pvmd3), and this will distinguish and allow multiple  virtual
	      machines	to run on the same set of hosts under the same userid.	(This feature was originally introduced by SGI in their commercial
	      PVM product, and has now been generalized for the public PVM system.)  This feature seems to be something that  people  often  want,
	      and  the	PVM_VMID  is the cleanest way to provide this functionality, rather than overloading the SHAREDTMP compiler flag and other
	      internals.
	      Setting the PVM_VMID environment variable before starting PVM will create an encapsulated virtual machine with the given VMID  name.
	      By  default,  all other hosts which are added to this virtual machine will inherit the same VMID.  If hosts are added to the virtual
	      machine which are running older versions of PVM (prior to 3.4.4), then the VMID will be ignored for those  hosts,  and  hence  these
	      machines	can  only  be added to one virtual machine for the given user.	The VMID need not be consistent on every host in a virtual
	      machine (although this is not necessarily advisable), and the VMID can be set for individual hosts using the "id=" host file  option
	      (see man page for pvmd3).

       The following environment variables are used by PVM internally.	With the exception of PVM_ARCH, their values should not be modified.  This
       is for information only.

       PVM_ARCH
	      The PVM architecture name of the host on which it is set, used to distinguish between machines  with  different  executable  (a.out)
	      formats.	Copies of a program for different architectures are installed in parallel directories named for PVM architectures.

       PVMSOCK
	      Is passed from pvmd to spawned task, and gives the address of the pvmd local socket.

       PVMEPID
	      Holds the expected process id of a spawned task exec'd by the pvmd.  This is a magic cookie used by the task to identify itself when
	      reconnecting to the pvmd, in order to get the correct task slot.

       PVMTMASK
	      The libpvm trace mask, passed from the pvmd to spawned tasks.

       PVMTRCBUF
	      The libpvm trace buffer size.  If specified determines the number of bytes of trace event message  buffer  to  be  collected  before
	      sending to front-end tracer program.

       PVMTRCOPT
	      The libpvm trace option setting.	Determines the level of tracing to be performed on invocations of PVM library calls.

       PVMINPLACEDELAY
	      Used to optimize sending of PvmDataInPlace messages on MPP systems.

       PVMKEY PVM  uses  this value, combined with the process id, to generate shared-memory segment keys.  The default value is your numeric uid.
	      PVM automatically detects collisions when generating a key and picks a new key, so it should almost never need to be set explicitly.

SEE ALSO

       aimk(1PVM), pvm(1PVM), pvmd3(1PVM), PVM 3.3 User's Guide and Reference Manual

AUTHORS

       A. L. Beguelin [4,5], J. J. Dongarra [1,2], G. A. Geist [2], W. C. Jiang [1], R. J. Manchek [1], B. K. Moore [1], V. S. Sunderam [3]

       1.  University of Tennessee, Knoxville TN.
       2.  Oak Ridge National Laboratory, Oak Ridge TN.
       3.  Emory University, Atlanta GA.
       4.  Carnegie Mellon University, Pittsburgh PA
       5.  Pittsburgh Supercomputer Center, Pittsburgh PA

								  11 April, 1995						   PVM_INTRO(1PVM)