next up previous contents index
Next: MVS systems Up: System specific details Previous: VM/CMS systems

VAX/VMS systems

Shared access (in the VAX Fortran sense of OPEN(LUN,SHARED,..)) can give rise to excessive RMS lock traffic in VAXcluster systems. If shared read access with concurrent write is required, you might wish to consider the use of a read-only copy of the RZ file, updated at regular intervals from the ``master'' file, to avoid such problems.

NFS access

Files residing on non-VMS systems that are accessed via NFS [10] should be processed using C I/O (option 'C' in RZOPEN). This is because such files are seen as STREAM\_LF to VAX Fortran and cannot be read with Fortran direct access.

Note that files created on most Unix systems are automatically in exchange mode, as exchange mode corresponds to native on such systems (IEEE floating point format). When reading these files, the option 'X' must be given on both the RZOPEN and RZFILE calls, as the file itself is not 'marked' as exchange mode.


Janne Saarela
Mon May 15 08:34:47 METDST 1995