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Porting linux application on cray machine

  1. May 25, 2010 #1
    I am trying to deploy my oceanic model currently runing on ubuntu linux and compiled with intel fortran on a cray sv1 machine with UNICOS operating system.
    It actually went quite well until i tried to read unformatted files. i am using the following code to export the data to the new machine:
    + form='unformatted',convert='little_endian')
    read(21) z,zz
    + form='unformatted',convert='cray')
    write(21) z,zz
    When i copy the produced file to the new machine and try running the model i get the following error massage:
    lib-5026 ./a.out: UNRECOVERABLE library error
    The COS blocked file contains an invalid BCW (block control word).
    Encountered during a sequential unformatted READ from unit 21
    Fortran unit 21 is connected to a sequential unformatted COS blocked file:
    Error initiated at line 225 in routine '_rdunf'.
    Beginning of Traceback:
    Interrupt at address 377677a in routine '_lwp_killm'.
    Called from line 32 (address 374366a) in routine 'raise'.
    Called from line 127 (address 302611d) in routine 'abort'.
    Called from line 59 (address 704047a) in routine '_ferr'.
    Called from line 225 (address 735714c) in routine '_rdunf'.
    Called from line 357 (address 676525a) in routine '_xfer_iolist'.
    Called from line 147 (address 742423c) in routine '_FRU'.
    Called from line 6347 (address 110006b) in routine 'BASIN'.
    Called from line 789 (address 2575a) in routine 'POM2K'.
    Called from line 350 (address 324455c) in routine '$START$'.
    End of Traceback.
    IOT trap (core dumped)
    the error is explained as:
    The COS blocked file contains an invalid BCW (block control word).
    A Fortran I/O or positioning operation or an FFIO() operation on a COS
    blocked file encountered a BCW (block control word) that is not valid. The
    file may not be a COS blocked file, or it may be corrupted.
    Ensure that the file is COS blocked; if it is not, use the appropriate
    specification on the assign(1) or asgcmd(1) command. If the file is
    corrupted, re-create it if possible.
    even after reading the section about the assign command this error massage is like Chinese to me.

    does anyone know how the file migration should be done?

    thanks yair
  2. jcsd
  3. May 27, 2010 #2
    just for the record i used formatted text files as suggested below:

    Unformatted files are non-portable, especially between machines with different word sizes and floating-point representations. There may be utilities available to help with the conversion. Simply writing an unformatted file on an x-86 or x-64 PC and reading the file on an SV1, which AFAIK does not use IEEE floating-point, will not work.
  4. May 27, 2010 #3


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    Homework Helper

    Use a text format file to exchange data. On some machines, unformatted I/O means text files, on others it mean binary files. On IBM mainframes, it's some wierd binary data that included offsets into memory, and on the old Fortran G compiler, reading text data with unformatted I/O sometimes read the data into the PSW's at low memory, crashing the computer (I had this happen twice before I realized it was my program crashing the system).
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