Importing large GADM vector data
Q: How do I import very large data in GRASS? I.e. from GADM <br\> A: In contrast to GADM v1, GADM v2 contains a lot of floating point representation errors in the coordinates, most probably created by the software used to create GADM v2. You need to perform additional cleaning with snapping to a very small threshold, i.e.
v.in.ogr snap=1e-7
And you should use GRASS 7 for the import of large vector data, because the import may not work with GRASS 6.