[GRASS-dev] Error reading raster data for row xxx (only when using r.series and t.rast.series)

[Dylan Beaudette]

Hi,

Over the last couple of years I have noticed a very strange raster
corruption (?) issues when using r.series, and now more recently,
t.rast.series. Typically, I'll generate a large number of maps with
r.sun or t.rast.mapcalc and then aggregate the series with r.series or
t.rast.series. About 50% of the time the command runs as expected, the
other half of the time r.series or t.rast.series gives me an error
like this:

Error reading raster data for row xxx (testmap)

After this error, I can no longer perform any kind of operation on map
"testmap" without the dreaded Error reading raster data for row xxx...

The situation was worse when using a MASK map, possibly related to a
similar (fixed?) issue discussed in this thread:

http://lists.osgeo.org/pipermail/grass-dev/2015-July/075627.html

Within that thread, Glynn mentioned that this type of error was
probably related to pthreads and concurrent processes. The temporary
fix entailed:

export WORKERS=0

I have tried this on my machine but the results are the same,
non-deterministic corruption (?) of one input to r.series or
t.rast.series.

I have encountered this error on several disks, mirrored HDDs, single
HDD, and now on an SSD. I don't think that this is a disk problem,
rather, something that r.series or t.rast.series is "doing" to the
files it operates on.

Is there some possibility that one of these commands is leaving a file
"open" or in some kind of intermediate state that prevents subsequent
commands from accessing the file?

I'll try to create a sample dataset to send over. In the meantime is
there any kind of diagnostic information that I can report back with?

Thanks,
Dylan