[GRASS-dev] ramdisk as mapset?

[David Finlayson]

What about running GRASS in something like Xgrid or Grid Engine?

I am about to purchase a cluster of Mac Pros for filtering and
rendering sonar data and I have been curious what has been done to
parallelize GRASS buy enterprising people. Grass isn't threaded so it
might work well on a cluster if you can keep the nodes fed with data.
Maybe some Franken-script could divide the raster data into segments
and launch a node on each segment.

I read a paper recently that documented using GRASS on GeoWalls via a
series of shell scripts that controlled the batch processing, but I
haven't looked into it in detail and can't remember the authors off
the top of my head.

Our data sets are toping 100 million points a piece and I am looking
for ways to divide and conquer the work load. Currently, I use GMT
across 8 nodes and it works well (if a bit clunky as far as job
management goes).

David



On 7/19/07, Glynn Clements <glynn at gclements.plus.com> wrote:
>
> "Sören Gebbert" wrote:
>
> > interesting idea. But lets put this idea into the library of grass. :)
> >
> > I would like to suggest to extent the grass lib to
> > read the entire map into the memory if needed.
>
> There's no advantage if you're doing sequential I/O, which is most of
> GRASS.
>
> Programs which do random I/O already have mechanisms to deal with
> this; e.g. r.proj reads the entire useful region into memory,
> r.proj.seg has its own tile cache, other programs (e.g. r.cost) use
> the segment library.
>
> If you are concerned about efficiency, build GRASS with profiling
> support, and look at where the actual inefficiency lies. It would help
> to do the same for 4.x, as that is reported to be an order of
> magnitude faster than 5.x/6.x for some tasks.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>
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-- 
David Finlayson, Ph.D.
Operational Geologist

U.S. Geological Survey
Pacific Science Center
400 Natural Bridges Drive
Santa Cruz, CA  95060, USA

Tel: 831-427-4757, Fax: 831-427-4748, E-mail: dfinlayson at usgs.gov