[GRASS-user] Re: Question concerning r.to.vect and out of memory error

[Hamish]

Rainer M. Krug wrote:
> > my system: SuSE 10.2, Dual core processor, 1GP physical memory, 16GB
> > 
> > swap (one swap partition of 1GB and one swap file of 15GB)
> > 
> > I have a huge DEM from which I calculated the slopes and categorised
> > 
> > them in 10% classes. Now I want to use r.to.vect to convert them
> > into a  vector layer of type area. My problem is that I get an out
> > of memory  error, even though there is enough memory available. It
> > seems that GRASS  6.2.1 only uses the swap partition and not the
> > swap file (which would be  really strange).
> > 
> > by using "free -m" , I got the following memory information (in 
> > megabytes) when r.to.vect quit with an out of memory error:
> > 
> >              total       used       free     shared    buffers    
> >              cached
> > Mem:          1011        998         12          0          1      
> >  103
> > -/+ buffers/cache:        894        117
> > Swap:        17299       1043      16255
> > 
> > Any ideas on how I can avoid this?
> > 
> > By the way: before I started grass, I created the swapfile with
> > 
> > dd ...
> > mkswap ...
> > swapon ...
..
> One additional information: huge means:
> Rows:         25960
> Columns:      23211
>      Total Cells:  602557560

does the map contain integers or floats?
 (CELL map, FCELL map, or DCELL? [from r.info])

Even with 16GB ram, Linux can only allocate so much per process.
see  http://kerneltrap.org/node/2450

Was GRASS built by hand with large file support?

Was your linux kernel built with CONFIG_HIGHMEM or similar?
32 or 64bit machine? 64bit linux kernel?


Hamish