saving parallel vectors

[Matteo Semplice]

This is really a newbie question but I am struggling to solve out of memory 
troubles on my first processor.

I have a parallel global vector, say v, that I obtain with a call to 
DAGetGlobalVector. I save it to disk opening an ASCII standard viewer on 
PETSC_COMM_WORLD and calling VecView. As I understand from the manual, this 
causes all processors to send their data to the first one and this one writes 
them to disk. This works fine for small computational grids, but hangs my 
program if the grid is bigger.

I am thinking to get each processor to write its own file and reassemble the 
data at the end of the program. I tried to create the viewer with the 
communicator PETSC_COMM_SELF and issue VecView. I get as many files as 
processors, but the first one contains all the data and the others are empty!

Why? And, more importantly, what's the best way to achieve my goal?

Thanks a lot.

     Matteo