[gradsusr] question about "Low Level I/O Error: Seek error on data file"

[Ricardo Hallak]

Hi, Paul.

I guess you are using LINUX.

In rare cases, and in old times, this kind of low level error here in our Department was, yes, related with the big file size.
In that time, the Linux OS were installed with a limitation in file sizes (something like 2.0 Gb, I guess). However, this problem practally disappered with new Linux versions.

If you are using 64bit machines and new versions of Linux OS, probably the problem is more complex.

Regrads,
Ricardo

----- Mensagem original -----
| Hello Grads users,
| 
| I was wondering if anyone has ever seen this Grads error before:
| 
| ga-> d zvort
| Low Level I/O Error:  Seek error on data file
|    Data file name = cm1out_00%y4_s.dat
| 650 rc=-1 fpos=-2110654536 pfi->fhdr=0
|    Error occurred when seeking to byte -8442618144
| Data Request Error:  Error for variable 'zvort'
|    Error ocurred at column 1
| DISPLAY error:  Invalid expression
|    Expression = zvort
| 
| In case it matters, I'm trying to display output from George Bryan's
| CM1
| model (CM1 is a popular cloud-resolving model used heavily in the
| convective storms community, but is also used by the boundary layer
| and
| mountain meteorology communities).  I've used Grads to display CM1
| output for 15 years, and this is the first time I've ever seen this
| strange error.  It might be noteworthy that I get this error only for
| some of the variables that I'm trying to display.  My output file is
| ~7
| GB.  I've tried both Grads 2.0.1 and 2.1.a3; same error with both.  I
| don't know if it has to do with the large file size; perhaps there's
| a
| "large memory" compile option that wasn't properly used when the code
| was compiled?  I'd be grateful for any insight you might have!
| 
| Paul
| 
| 
| 
| 
| --
| Paul Markowski
| Professor of Meteorology
| Department of Meteorology and Atmospheric Science
| Pennsylvania State University
| 520 Walker Building
| University Park, PA 16802
| email: pmarkowski at psu.edu
| phone: 814.865.9736
| web: http://sites.psu.edu/pmarkowski
| 
| _______________________________________________
| gradsusr mailing list
| gradsusr at gradsusr.org
| http://gradsusr.org/mailman/listinfo/gradsusr
| 

-- 
Prof. Ricardo Hallak
Laboratório de Meteorologia de Mesoescala - LMM
Departamento de Ciências Atmosféricas
Instituto de Astronomia, Geofísica e Ciências Atmosféricas
Universidade de São Paulo

Phone: +55(11)3091-4698