I am running GRASS 7.3 on Mac OS X El Capitan (2.9GHz, 8GB RAM). I have had to disable SIP in order to run it, but it works. I am hoping to perform some hydrological analyses on a few DEMs. My DEMs are 5ft resolution county-scale rasters totaling a few GB apiece but I have performed lots of large-raster operations (outside of GRASS) on this machine with no issues.
When I run r.fill.dir, everything goes smoothly at first; the input raster loads quickly and within the first 5 minutes or so the first two sets of downward/upward passes have completed. Downward pass 3 takes several hours(~5.5 - 6.5) before the command apparently finishes successfully. However, when I look for the output rasters, they do not exist.
I have tried this multiple times, including with a reprojected version of the raster. Same result each time. I always make sure to set the region to match my raster before running the command.