pnetcdf strange behavior

[Hongzhang Shan]

Hi,

  I am testing pnetcdf1.02pre. My test case is very simple, using 8 
processors to create a 8GB
file with each processor to write 1GB. I found that the file size 
quickly grows to 7GB and then
grows much slower from 7GB to 8GB. Does this mean something goes wrong 
with my code
or the first 7GB is only allocated without actually writing the data.

Thanks!

shan