Computer data file backup system

Claim 1

A computer file data backup system which comprises: a) a client computer having a client disk image, composed of a plurality of client data files, having a set of selected attributes on a client computer storage means, for storing said client data files; b) means for providing a client disk map composed of attributes of the client data files from the client computer; c) a separate server computer, having a server computer storage means solely for receiving and storing said client disk image as a client logical disk image; d) means to transmit, by a client from the client computer, said client disk image in logical form into said server computer storage means to create a stored client logical disk image; e) means to update, periodically by the client in said client computer, said client disk map, with a previous client disk map, to identify any client data files with additions, modifications or deletions occurring since the last update of the previous client disk map to provide a revised client disk map; f) means to transmit from the client computer, and to receive and store only in said storage means of said server computer, the added or modified client data files, and to remove said deleted client data files to provide a stored, revised, updated, client logical disk image in said server computer storage means; and g) means to acknowledge the completion of the transmission between said server computer and said client computer.