Introduction
The OpenIFS tarfile distribution includes a simple low resolution (T21) test job that can be used to verify the model is working correctly in the directory: oifs/t21test. It is strongly recommended that after compiling the model successfully, these short tests are run.
Test directory
The directory oifs/t21test contains a number of files:
% cd oifs % ls t21test ICMGGepc8 ICMGGepc8INIUA ICMSHepc8INIT ifsdata namelists ref_021_0018 ICMGGepc8INIT ICMSHepc8 README job ref_021_0006 ref_021_0144
Files beginning with 'ICM'.
These are the input files for this T21 experiment. They are in GRIB format. Do not move them from this directory. OpenIFS expects to find it's input files in the same directory as the main executable.
epc8 - this is the Experiment ID.
ICMGGepc8 - 'GG' indicates these contain gridpoint fields.
ICMSHepc8 - 'SH' indicates these contains spherical harmonic fields.
You can use the 'grib_ls' and 'grib_dump' commands to see the contents of these files (grib_ls/dump will be in your grib_api directory).
job
Simple shell script to run the model. Described in more detail below.
ifsdata
Climate data fields used for T21 test integration. You should not move or rename this directory as the model will expect to find the climate files it needs in a directory of this name.
namelists
This file contains all of the input model fortran NAMELISTS. Not all of the namelists have their variables listed, only the variables commonly changed are listed here. Users should copy this file and modify it for the tests described below.
ref_021_*
These files are reference output for the model tests. The model can be run in 'reference' mode where it checks it is working correctly by comparing some mathematical norms against these files. Reference runs are described in more detail under 'Acceptance testing' below.
Test integrations
A number of short model runs are recommended to verify the model is working correctly. Once you have compiled the model without errors, follow these steps.
These tests will ensure the model can run with multiple OpenMP threads, with MPI tasks and in mixed OpenMP/MPI mode. A further acceptance test can be run which compares the model output on your machine with reference data obtained from machines at ECMWF.
Serial : single task, single thread.
- cd oifs/make and build the model using the 'opt' build configuration.
cp oifs/t21test and edit the file 'job' to change the line beginning:
export GRIB_SAMPLES_PATH=...
to match the location of your grib_api installation. The model will fail with an error if it cannot find the 'ifs_samples' directory in the grib_api installation.signal_drhook(SIGSYS=31): New handler installed at 0x4d06cf; old preserved at 0x0 MPL_BUFFER_METHOD: 2 0 GRIB_API ERROR : Unable to locate sample file gg_sfc_grib1.tmpl in /home/rd/openifs/software/grib_api/1.9.18/grib_api-gcc-4.5.0/ifs_samples/grib1_mlgrib2 GRIB_NEW_FROM_TEMPLATE gg_sfc_grib1 FAILED -2
- cp namelists fort.4
The model will look for a file 'fort.4' to read its fortran namelists from. Run the model with a single task and single thread by executing the job script:
./job
If the run works you will see output like this:signal_drhook(SIGSYS=31): New handler installed at 0x4d06cf; old preserved at 0x0 MPL_BUFFER_METHOD: 2 0 16:03:46 STEP 0 H= 0:00 +CPU= 3.598 16:03:46 STEP 1 H= 0:10 +CPU= 0.535 16:03:47 STEP 2 H= 0:20 +CPU= 0.537 16:03:48 STEP 3 H= 0:30 +CPU= 0.537 16:03:48 STEP 4 H= 0:40 +CPU= 0.527 16:03:49 STEP 5 H= 0:50 +CPU= 0.526 16:03:49 STEP 6 H= 1:00 +CPU= 0.530
This test runs only 6 timesteps. The model writes its output to a several files. The NODE_00
If you see an error like this:
mpirun noticed that job rank 0 with PID 7429 on node elvira exited on signal 11 (Segmentation fault).
or
MEMORY FAULT
it is most likely because OpenIFS requries more 'stack' memory than your default setting. Sometimes, this can happen when increasing the number of OpenMP threads.
To solve the problem add the line:
ulimit -s unlimited
to the file job just before the mpirun line. This will increase the per-process stack memory limit to the maximum the operating system allows.
If the model still fails, contact openifs-support@ecmwf.int for assistance.
Parallel: 2 threads and 2 tasks
These next short tests verify the model works correctly with either OpenMP parallel threading, MPI tasks and both and follow on from the serial tests above.
Acceptance testing