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

[Paul Markowski]

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