There is a wonderfully easy way to install cdo, which takes care of all the libraries for you, and you can do it within your user directory, so don’t need special privileges: use conda!
conda config --add channels conda-forge conda update --all conda install cdo cdo
https://code.mpimet.mpg.de/projects/cdo/wiki/Anaconda
This cdo seems to work happily with GRIB and NetCDF data, and also installs lots of other useful tools, in particular
grib_to_netcdf
To convert IFS from GRIB to NetCDF, I think the best command to use may be:
grib_to_netcdf -T /pithos/shared/ESIPP/ECMWF/IFS/IFS_IT00_20180101_20180107.grib -o IFS.cdf
The “-T” option is good here, as it converts the data using the dimensions:
longitude = 80 ; latitude = 58 ; step = 49 ; date = 7 ;
where date is when the forecast started (initialisation time, IT), and step is the forecast time (0 to 48).
Fantastic!