Patent ID: 8825600

Claim:
A file backup apparatus for backing up one or more directories comprising: an estimation unit configured to estimate whether a particular file has been changed in a particular directory based on directory property information of all directories accessible by the estimation unit, wherein each accessible director contains one set of directory property information specific to that accessible directory; and a backup unit configured to select the entire particular directory for backing up in response to the particular directory being estimated to have the particular file changed, wherein the estimation unit, the backup unit, or any combination thereof is implemented by at least one computer processor, and the estimation unit is further configured to access all the accessible directories and estimate whether at least a file has been changed in all the accessible directories prior to the backup unit selecting the directories to be backed up; wherein the backup unit is further configured to back up a directory in response to the directory not having been selected to be backed up and not having been backed up for a predefined period of time.