[GRASS-user] GRASS 7 error code 9

[Hamish]

Pankaj wrote:
> Is there any GRASS - internal limit on usage of
> memory.

No, not that I know of. Usually it is the operating
system which poses the limit.

there is of course the possibility of a small bug
somewhere getting in the way, but for the most
part I would expect it to cope with large rasters
remarkably well.

note that at a region size of 46341 x 46341 we
get to 2^31 cells, and to the point where a signed
32bit integer overflows and wraps backwards on
itself. If that were the case I'd suspect a malloc
error or a segfault not SIGKILL, but it may be a
clue.


> Perhaps , due to my past experience of working
> with big files, I had set aside approximately
> 200gb of swap space during installation of linux.

ok, then you are well ahead of me. :-)

> And, I understand that GRASS shares the same space
> for its memory requirement.

GRASS simply uses the operating system's available
resources, but individual modules typically handle
things themselves. In this case I hope that Markus
Metz is able to help, as he rewrote much of that
code and first made it possible to run the
r.watershed module with large arrays, and may
have run some large-raster tests in the past.(??)


have you tried the same region with r.terraflow?


Hamish