[GRASS5] r.series: WARNING: Too many open raster files

[Markus Neteler]

At time I am processing time series of MODIS data,
unfortunately I get:

wc -l /tmp/lstlist2003
    362 /tmp/lstlist2003
r.series  in=`cat /tmp/lstlist2003 | tr '\n' ','` \
   out=modis.av method=average
WARNING: Too many open raster files

I was expecting something similar, is there any risk
to increase this number?
grass57/lib/gis/G.h
G.h:#define MAXFILES    256  

The maps are quite small:
rows:       908
cols:       1040
Data Type:    DCELL = xx bytes

Is memory an issue?
908 * 1040 * xx * 362 = 341843840 * xx 

The machine has 2GB RAM and enough swap space.
Other side effects to be expected?

Markus