As a long shot, you might try this. Change line 253 (or near) in posixio.c from while((partial = write(nciop->fd, nvp, nextent)) != -1) { to while((partial = write(nciop->fd, nvp, nextent)) > 0) { =Dennis Heimbigner Unidata Ticket Details =================== Ticket ID: IWC-920640 Department: Support netCDF Priority: Normal Status: Closed