XIOS, or XML-IO-Server, is a library dedicated to I/O management in climate codes targeted for large core simulation (> 10 000) on climate coupled models.

XIOS manages the output of diagnostics and other data produced by climate component codes into files and offers temporal and spatial post-processing operations on this data. 

XIOS aims at simplifying the I/O management by minimizing the number of subroutines to be called and by supporting a maximum of on-line processing of the data.

• To explore the use of XIOS to address three main challenges for climate data production:
  • Flexibility in management of I/O and data definition.
  • I/O performance.
  • Post-treatment.

• Describe the XIOS-XML terminology and structuration.
• Test XIOS on a specific architecture.
• Use one or more processes dedicated exclusively to the I/O management to obtain:
  • Simultaneous writing and computing by an asynchronous call.
  • Asynchronous transfer of data from clients to servers.
  • Asynchronous data writing by each server.
• Use of parallel file system ability via Netcdf4-HDF5 file format to obtain:
  • Simultaneous writing in the same single file by all servers.
  • No more post-processing rebuilding of the files.