I apologize for not responding to these emails earlier…. Here is a basic algorithm for using NEMESIS when starting with a file format that _isn't_ already EXODUS _and_ your mesh is so large that you can't read it on "n" number of processors.
1. Read file into libMesh 2. Write out Exodus file 3. Run nem_spread on the Exodus file to generate Nemesis files (one for each processor) 4. With a version of your code compiled against a libMesh that is using parallel mesh… use the nemesis reader to read the nemesis files. nem_spread is a _serial_ process that produces "n" number of nemesis files (it is doing an "offline" partitioning). You will need a machine with quite a bit of RAM. Derek On Nov 1, 2011, at 1:39 PM, Roy Stogner wrote: > > On Mon, 31 Oct 2011, [email protected] wrote: > >> I never succeeded to write the nemesis files for the different >> processors. I only get one file which, I can't read in i parallel >> because the program searches the files mesh.8.0, mesh.8.1, mesh.8.2, >> ... . How can I get these files when reading in the serial tetgen >> mesh on one processor? > > Yeah; right now libMesh assumes that you're reading in a Nemesis file > that's already partitioned on n_processors(), and libMesh only lets > you write out a Nemesis file that's using your current partitioning on > n_processors(). Kind of a catch-22 if you want to write with > n_processors()==1 then read with n_processors()==8. > > For N-to-M restarts, I think our only option is a third-party tool: > > http://sourceforge.net/projects/seacas/files/ > > There's a utility called nem_spread that you can build from the > seacas.tar.bz2 sources there; I've never used it myself but IIRC the > INL folks have been using it successfully with libMesh Nemesis I/O. > --- > Roy > > ------------------------------------------------------------------------------ > RSA® Conference 2012 > Save $700 by Nov 18 > Register now! > http://p.sf.net/sfu/rsa-sfdev2dev1 > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users ------------------------------------------------------------------------------ RSA® Conference 2012 Save $700 by Nov 18 Register now! http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
