wiki:UmFamous

Version 6 (modified by simon, 3 years ago) (diff)

Standalone UM system and FAMOUS

This is a standalone version of FAMOUS based on version 4.5 of the Met Office's Unified Model (UM).

It is a complete UM system but without the need for the complicated installation process. It is linux only as it comes with pre-built small executables. It also comes with prebuilt model and reconfiguration executables. If no model code changes are needed, then the model executables can be used for model integration without the need for any compilation at all on the installation machine. The system has the flexibility for local compilation, if required. This does need extra work, however. The communications library, gcom will need installing, together with a MPI system, see below for full details.

Prerequisites:

Running without compilation:

  • Linux system
  • at daemon
  • ksh

Running with compilation (above plus):

  • Intel fortran
  • MPI

Quick start guide:

  1. Copy um_famous.tgz and unpack on the machine on which you want to run FAMOUS.
  1. Edit and append example.profile to your $HOME/.profile
  • Ensure that there is no other UM setup commands in .profile
  • UMDIR should always have um_famous at the end of the path.
  1. Then
    . $HOME/.profile
    
  1. On puma, copy the job xmjne (MOSESI) or xmjnf (MOSESII), save and process. The "Submit" button DOES NOT WORK. As prebuilt executables are provided, there is no need to build the model. These model configs require no further changes
  1. On the installation machine type:
    umsubmit_local -u pumaid runid
    
  2. And the model should be running. Check by:
    cd $DATA_DIR/runid
    tail -f *pe0
    

FAMOUS configuration

Intel FORTRAN, MPI and gcom

The model tarball comes complete with a pre-built MPICH3.2 system. The default installation is configured to use this. If the model needs recompilation, or a different MPI system than MPICH3.2 is required to run the model (for example on some clusters), then the model needs to be recompiled on the local system. Firstly Intel FORTRAN needs to be installed. In theory it is possible for this FAMOUS version to use other compilers, but currently only Intel FORTRAN is supported. MPI has to be installed (if it hasn't been already). FAMOUS has been tested with MPICH3.2 but should work with other implementations. For MPICH3.2 follow the installation instructions at https://www.mpich.org/ . It needs to be configured for Intel FORTRAN for both F77 and F90. Once it has been installed, add the line

export MPICH_DIR=/path/to/top/level/mpich

to your .profile, before the call to setvars, changing the path as required. If MPI is already installed, then add this line to point to the local installation.

Next gcom (the system the model uses for multi-processor communications) needs to be compiled using MPI. Type

cd $UMDIR/gcom3.8/gcom
make

The file $UMDIR/gcom3.8/gcom/lib/libgcom_buffered_mpi.a should now exist.

The reconfiguration and model can now be compiled as usual. The standard compile system will use the MPI version defined in MPICH_PATH and the gcom version in $UMDIR/gcom3.8/gcom/lib.

Changes from standard UM/FAMOUS

  • Linux only.
  • UM comes as a single pre-configured tarball.
  • UM installation process no longer required.
  • UM tools included in tarball.
  • Scripts are hard coded, no script mods.
  • All small executables are prebuilt as static executables.
  • All mods grouped together into a small number of files.
  • Compile system changed so that pre-built object files no longer required.
  • All handedit file collated into a single file.
  • umui jobs cleaned up.
  • umui updated to set values directly which handedits overwrote. These handedits removed.
  • umui system code updated.
  • Dumps and ancils co-located.
  • MPICH built and included with system for multi-processor models.
  • Changed paths so that only minimal only two (UMDIR DATA_DIR) need changing.
  • Ensured that system is flexible enough to allow UM experts to configure as they would a standard UM system.
  • Archiving system fully integrated with model scripts.