Problems displaying GRASS raster layers

[William Hudspeth]

Hello All,

I am having problems getting GRASS raster layers to display. I am using
the Python mapscript module. When I try to display a GRASS layer, I get
the following error:

.....
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109]
phairmap.draw_map()!!!!#build the map image and store in /tmp
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109]   File
"/var/www/cgi-bin/reason/mapmodule.py", line 61, in draw_map
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109]
self.map_image=self.nmMap.draw()
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109]   File
"/usr/local/lib/python2.3/site-packages/mapscript.py", line 1759, in
draw
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109]     def draw
(*args): return _mapscript.mapObj_draw(*args)
[Tue Dec 14 15:37:37 2004] [error] [client 10.16.1.109] IOError:
msDrawRaster(): Unable to access file.
(/home/bhudspeth/grass_data/western_us/mod08_ozone/cellhd/dem_scale)

My Mapfile entry looks like this:

LAYER
 NAME "DEM"
 TYPE RASTER
 STATUS ON
 DATA /home/bhudspeth/grass_data/western_us/mod08_ozone/cellhd/dem_scale
END

My machine setup is as follows:

1. Red Hat Fedora Core 3
2. Mapserver Version 4.2.1
3. GDAL version  1.1.9.0  - GRASS database rasters ARE enabled (i.e.,
GRASS: GRASS Database Rasters)
4. Running GRASS 5.3

Having read various mailing list postings and relevant text in "Open
Source GIS: A GRASS GIS Approach", I have made sure that the following
steps have also been taken:
1. I have placed a copy of the .grassrc53 file in $DocumentRoot as
specified in httpd.conf file (/var/www/html2)
2. GRASS LOCATION group and owner is set to Apache (the book cited above
indicates that the GRASS LOCATION data for UNM/Mapserver have to be
stored with the same user-ID as the Web Server is running)

I would very much appreciate any help on addressing this error. Thanks,
Bill Hudspeth