Large Scale I/O

Visualization of the 1994 Northridge earthquake simulated with the CVM-H

SeisSol provides highly tuned I/O routines to handle unstructured meshes with several hundred millions of cells and billions of unknowns. The I/O routines are adapted for the complete workflow from a CAD model to the final result. SeisSol is able to read the large meshes from XDMF/HDF5 files and automatically partitions the mesh at runtime using ParMETIS. The tool PUMGen creates the customized files directly from CAD models or other mesh formats. In addition to the mesh, SeisSol can load complex material structures using ASAGI. For writing visualization and post-processing output (wave field, fault, and surface), the XdmfWriter, a small header-only C++ library is used. The library aggregates the output from all processes into a few files and aligns the data to the file systems blocks. The output is written in the XDMF format and can be visualized with common tools such as ParaView or VisIt without further post-processing. SeisSol also provides multiple checkpoint back-ends based on POSIX I/O, MPI-IO and HDF5 to restart the simulation in case of failures. Both, the visualization output and checkpoints, can be written using asynchronous I/O.


I/O Overhead
Overhead for I/O on 3072 compute nodes of SuperMUC depending on the I/O mode