Thomas Zeiser

Some comments by Thomas Zeiser about HPC@RRZE and other things


Compiling user subroutins for STAR-CD at RRZE

STAR-CD can be extended with user subroutines. To compile the user code, a compatible Fortran compiler is required. Unfortunately, CD adapco’s standard compiler for Linux still is Absoft for which no license is available. However, for most versions of STAR-CD for Linux x86_64 at least, also a PGI version is available. Thanks to the financial engagement of one of the main users’ group, a PGI license can now be used on the frontends of the Woody cluster (and also on sfront03). If you have user subroutines, please generally use one of the 64-bit PGI-STAR-CD versions (usually but not always with “pgi” in the module name), to compile the user code login to woody.rrze (or sfront03.rrze if you run your simulations e.g. on the opteron queue of Cluster32 (“Transtec cluster”), load the appropriate STAR-CD module and “pgi/6.2-2” and compile your user routines using star [-dp] -ufile. Now, you can submit your code as usual. Automatic compilation of the user subroutines from within a job file may or may not work. Thus, please compile them in advance before hand.

An important note: STAR-CD as of 3.2x does not work together with the latest PGI versions (7.x). Thus, you have to explicitly select version 6.2-2 of the PGI compiler; nobody tested yet which PGI versions are compatible with STAR-CD 4.0x … please drop a note if you are the first volunteer.

Attention: Interactive access to thor.rrze for compiling user code is no longer possible (and also no longer necessary). Use the woody login nodes or sfront03 instead.

The description in my previous article thus in principle is still valid.

STAR-CD 4.06 has just been installed. If the corresponding module is loaded, the appropriate PGI compiler module will be loaded automatically.

Existing star.reg files may cause problems: With STAR-CD 4.06 we just discovered a very strange behavior: if there is a star.reg file present, star -ufile tries to ssh to the first node listed in PNP_HOSTS (if present in star.reg and do the compilation there – which of course usually fails as users are not allowed to login to batch nodes without having a job running right now on them. The definition of a COMPILERHOST also is no solution as (1) star.reg is still evaluated and (2) STAR-CD tries to make a ssh connection to COMPILERHOST which works but then fails as there is no PGI module loaded.
To sum up: if you have to compile user subroutines, do this on the login nodes by calling star [-dp] -ufile but make sure that there is no star.reg file in the current directory. As star.reg does not contain critical information, it should be safe to just delete it if is is in the way.