We have a data conversion project where the overall process works this way:

1. Mainframe legacy application will extract out their data into flat text files.
2. Our application (running on AIX) will FTP to the mainframe and pick up the flat text files.
3. We will run our conversion on the flat text files and generate a set of mapped/transformed files.
4. We will transfer the files to the new system for importing.

The mainframe apps' files are about 2TB large. Obviously, the data transfer represents quite a large overhead. 

Is is possible for the mainframe to write to a set of disk volumes on the SAN, unmount the volumes after writing and we mount those volumes on AIX? Is there any file system that is readable/writable by both z/OS and AIX?

Thanks,
Wong