1. Generalities

By default, the JEVEUX memory manager used in Code_Aster uses several binary direct access files. These files constitute the « bases » JEVEUX, the data structures that will be used again in case of continuation of the calculation are stored in the database GLOBALE in a format specific to the memory manager. During the calculation, the memory manager is required to use the databases to temporarily unload the memory, so the access mode chosen for its performance in this mode of use is not suitable for a backup, especially if it is desired to make them independent of the platform.

The use of the HDF library, already used in the context of the MED data exchange format, for writing the content of the JEVEUX databases proves to be much more suitable. The file obtained after saving can easily be transferred, after possible compression, to a local platform to perform post-processing operations with a ported version of Code_Aster, for example.

A file in HDF format is organized like a unix file tree, the concept of « group » is similar to the concept of directory, the concept of « dataset » corresponds to the file. In addition, it is possible to assign attributes to each level of « group » and/or to each « dataset ». We used these few notions to organize the copying of all the JEVEUX objects contained in a database.

HDF provides a utility (h5dump) that allows you to write the content of an entire file in ASCII format, so it is very easy, for reasonably sized files, to obtain the content of all the objects that make up a JEVEUX base.