US Patent 8984097 Efficient file replication which preserves the underlying extent structure

A system and method for replicating a set of files from a source computer system to a target computer system are described. The underlying extent structure of the files may be preserved. For example, if an original file on the source computer system has a particular number of extents then the copy of the file created on the target computer system may have the same number of extents, where each respective extent in the copy represents the same byte range of the file as its corresponding extent in the original file. The file systems employed on the source computer system and the target computer system may support different extent types. The extent types of the original files stored on the source computer system may be preserved in the copies of the files on the target computer system.