[GRASSLIST:3214] Re: GRASS-Python, or, Alber'salgorithm?/r.proj with big files

[Gordon Keith]

On Tue, 26 Feb 2002 07:39, Len Coop wrote:
> I forget the number of rows-cols that I was able to re-project when I
> bumped my PIII 550 box
> from 256 MB to 384 MB, but it was less than the 20000x24000 (90 MB)
> file I would like to reproject at the moment.
>
> My new box (PIV 1.9 Ghz) has .5 GB Rambus memory,
> which would be expensive to toss and replace with 1 GB, but I suspect
> that would NOT be enough for these NLCD files. As it goes now, I
> CRASH the box running r.proj, requiring a cold boot, which I have
> never run into before with Linux (the process should die and not take
> the whole operating system down with it). Here is the final thing I
> see (this after downsizing output resolution) before the box freezes:

What size swap do you have?

I found that grass would crash my linux box when I ran out of swap 
space on my .5GB RAM machine (I have a 1.5GB swap partition) so I added 
two 2GB swapfiles and it hasn't been a problem since (yet). So far I 
haven't needed much more than 3GB swap. 

su
dd if=/dev/zero of=/var/swapfile bs=1024 count=2048000
mkswap /var/swapfile
swapon /var/swapfile

repeat for /var/swapfile2

You'll have to add the swapon command somewhere in the boot sequence if 
you want it add the swap files when you reboot - I haven't bothered as 
it's easy enough to add when needed and easy to trash the swapfiles 
when I have more need for disk space.

Of course swap is much slower than ram but these big jobs take long 
enough I prefer to do them overnight anyway.

-- 

Gordon Keith
Programmer/Data Analyst
Marine Acoustics
CSIRO Marine Research
http://www.marine.csiro.au

"Computers are useless. They can only give you answers." Pablo Picasso, 
1968