Porting linux application on cray machine

AI Thread Summary
The discussion centers on the challenges of migrating an oceanic model from a Cray SV1 machine running UNICOS to a new machine using Ubuntu Linux, specifically regarding the handling of unformatted Fortran files. The user encounters a critical error when attempting to read unformatted files, indicated by the message about an invalid block control word (BCW). This error suggests that the file may not be properly formatted for the target system, highlighting the non-portability of unformatted files, especially between different architectures with varying word sizes and floating-point representations. The advice given emphasizes the importance of using formatted text files for data exchange to avoid such issues, as unformatted I/O can differ significantly across systems. The discussion also notes that utilities may exist to assist with file conversion, but the user expresses confusion regarding the specifics of the migration process and the use of the assign command for file handling.
yairsuari
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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:
file_name=trim(datafolder)//'basin'
open(21,file=file_name,status='old',
+ form='unformatted',convert='little_endian')
read(21)h,alat,alon,dx,dy
read(21)fsm,dum,dvm
read(21) z,zz
close(21)
file_name='~/Documents/temp/phys/data/basin'
open(21,file=file_name,status='new',
+ form='unformatted',convert='cray')
write(21)h,alat,alon,dx,dy
write(21)fsm,dum,dvm
write(21) z,zz
close(21)
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:
"/users/negev1/biu/ysuari/prog/bfm_3dcode/phys/data/basin"
Error initiated at line 225 in routine '_rdunf'.
Abort
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
 
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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.
 
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 weird 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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