1. Adds redundancy files to archives for data recovery. Ras is a program that adds m extra files to a set of n files, such that the contents of the n original files can be regenerated from any n of the n+m original files and extra files. Normally, these extra files will all be 6 bytes larger then the largest of the original files, but ras has a mode in which the extra files are exactly the same size as the original files. Ras was originally intended for transporting a large file split over several floppy disks in a manner resilient to the corruption of a few of the disks, and a pair of example shell scripts to do this (rassplit and rasmerge) is included in the distribution. From Debian 3.0r0 APT