the ompio software infrastructure has multiple frameworks. fs framework: abstracts out file system level operations (open, close, etc)
fbtl framework: provides the abstractions and implementations of *individual* file I/O operations (seek,read,write, iread,iwrite) fcoll framework: provides the abstractions and implementations of *collective* file I/O operations ( read_all, write_all, etc.) sharedfp framework: provides the abstractions and implementations *shared file pointer* file I/O operations (read_shared, write_shared, read_ordered, write_ordered). Feel free to ping me also directly if you need more assistance. If you are looking for a reference and more explanations, please have a look at the following paper: Mohamad Chaarawi, Edgar Gabriel, Rainer Keller, Richard Graham, George Bosilca and Jack Dongarra, 'OMPIO: A Modular Software Architecture for MPI I/O', in Y. Cotronis, A. Danalis, D. Nikolopoulos, J. Dongarra, (Eds.) 'Recent Advances in Message Passing Interface', LNCS vol. 6960, pp. 81-89, Springer, 2011. http://www2.cs.uh.edu/~gabriel/publications/EuroMPI11_OMPIO.pdf Best regards Edgar -----Original Message----- From: users <users-boun...@lists.open-mpi.org> On Behalf Of Ognen Duzlevski via users Sent: Monday, November 2, 2020 7:54 AM To: Open MPI Users <users@lists.open-mpi.org> Cc: Ognen Duzlevski <mak...@sdf.org> Subject: Re: [OMPI users] ompe support for filesystems Gilles, Thank you for replying. I took a look at the code and am curious to understand where the actual read/write/seek etc. operations are implemented. From what I can see/understand - what you pointed me to implements file open/close etc. operations that pertain to particular filesystems. I then tried to figure out the read/write/seek etc. operations and can see that a MPI_File structure appears to have a f_io_selected_module member, whose v_2_0_0 member seems to have the list of pointers to all the functionals dealing with the actual file write/read/seek functionality. Is this correct? What I would like to figure out is where the actual writes or reads happen (as in the underlying filesystem's implementations). I imagine for some filesystems a write, for example, is not just a simple call to the write onto disk but involves a bit more logic/magic. Thanks! Ognen Gilles Gouaillardet via users writes: > Hi Ognen, > > MPI-IO is implemented by two components: > - ROMIO (from MPICH) > - ompio ("native" Open MPI MPI-IO, default component unless running > on Lustre) > > Assuming you want to add support for a new filesystem in ompio, first > step is to implement a new component in the fs framework the framework > is in /ompi/mca/fs, and each component is in its own directory (for > example ompi/mca/fs/gpfs) > > There are a some configury tricks (create a configure.m4, add Makefile > to autoconf, ...) to make sure your component is even compiled. > If you are struggling with these, feel free to open a Pull Request to > get some help fixing the missing bits. > > Cheers, > > Gilles > > On Sun, Nov 1, 2020 at 12:18 PM Ognen Duzlevski via users > <users@lists.open-mpi.org> wrote: >> >> Hello! >> >> If I wanted to support a specific filesystem in open mpi, how is this >> done? What code in the source tree does it? >> >> Thanks! >> Ognen
