On Fri, Aug 12, 2011 at 19:23, Justin A. Lemkul <jalemkul at vt.edu> wrote: > Try setting the environment variable GMX_MAXBACKUP to zero. This environment variable is read only by the 4.5 series. In 4.0.7 there is no way to control it, there is a hard-coded limit of 128. Cheers, Bogdan