When GRASS writes a raster file, it is really writing to a
tmp file, using the PID to generate a name in the user's
$LOCATION/.tmp/machinename directory. When the file is
CLOSED, it is renamed to the cell directory, so I would
guess that the process that finishes last will overwrite
the previously generated files.
- Bill
Hi:
Recently, one of my users has (inadvertently) gotten
into the situation where multiple instances of EXACTLY
the same GRASS job have been run in the background.
This is on a Linux installation. All the programs
are working with the same region of data, which shouldn't
be a problem, and all of them are using the same file
for input (which is not being modified by any of the
programs). But what I am having problems understanding
is how GRASS can let multiple jobs write to the same
file? Doesn't GRASS grant the first program to run an
exclusive write file lock? Shouldn't the remaining
GRASS programs die since they cannot get write access on
the file?