Hello Jose,
This worked for me (although I did not process any data that way, the concurrent use works):
go in the directory parent directory of your GISbase, for example:
home/jose/grassdata/..
in this directory, if you type
$ ls -attr
you should see a .grassrc53 and a .gislock53 file
well, if you start grass in a first terminal, open a second one in witch you remove these two files
rm -f .grassrc53; rm -f .gislock53
then you should be able to start a second grass environment (when you run grass, specify the environment, such as $ grass53 /home/jose/grassdata2/location2/mapset2)
the job of .grassrc53 is to give the gis base, location and mapset location on the hard drive
the job of the .gislock53 file is .. well guess what!
As I said earlier, it worked for me but I did not try to process data that way; I would recommend to use different gisbases. As well, I am sure that the people that designed grass blocked concurrence use for a specific reason, which I do not know (I would be happy to find out, though!)
good luck !!!
eric pante
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<DIV align=left>Eric Pante</DIV>
<DIV align=left><FONT size=2>Graduate Student in Marine Biology</FONT></DIV>
<DIV align=left><FONT size=2>Grice Marine Laboratory</FONT></DIV>
<DIV align=left><FONT size=2>205 Fort Johnson, Charleston SC 29412</FONT></DIV>
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<DIV align=center><EM>On ne force pas la curiosité, on l'éveille.</EM></DIV>
<DIV align=center>Daniel Pennac</DIV>
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>From: Jose Luis Gomez-Dans <jgomezdans@yahoo.co.uk>
>To: GRASSLIST@baylor.edu
>Subject: [GRASSLIST:5984] Concurrent use of GRASS
>Date: Thu, 3 Mar 2005 16:04:25 +0000
>
>Hi!
>I have a dual CPU machine, and I would like to run several GRASS
>programs in parallel. I found that since I need to change regions, I
>end up having race conditions, and endless grief. I would rather just
>use two different GRASS sessions to do things (maybe with a different
>location). However, GRASS complains that
>${USER} is currently running GRASS 5.4.0. Concurrent use not allowed.
>
>I can easily get over this by running GRASS on two different machines,
>but I'd like to use my 2nd CPU for GRASS programs!
>
>Choose as many as you like:
>a. Did I do something stupid?
>b. Did I misread the manual?
>c. Did I err? (Groo the Wanderer)
>
>thanks!
>Jose
>--
>Jose L Gomez-Dans, Research Assistant
>Bristol Glaciology Centre, Geographical Sciences/CPOM
>University of Bristol, Bristol, UK
>
