1. A method for data backup and recovery based on linked file repositories with each of the linked file repositories representing an individual file system capable of storing at least one version of a file and being connected to at least one server system, wherein the method includes: placing each of the linked file repositories in one of a plurality of positions for storing the at least one version of the file; continuously numbering each of the plurality of positions of each of the linked file repositories; determining a number of the at least one version of the file by the one of a plurality of positions of the one of the linked file repositories; and implementing a version-recovery process over each of the linked file repositories to perform a read operation of the at least one version of the file.