An apparatus is operable with a host and a data storage component for controlling expansion of storage, and comprises: an allocating component responsive to a user input for allocating an expanded target storage space to a file system element to thereby make an expanded file system element; a file system metadata component for maintaining file system metadata including metadata for the expanded file system element; a file system I/O component responsive to the file system metadata component for controlling file system I/O between the host and the storage component; and a synchronizing component responsive to the file system metadata component for synchronizing data between a source storage space and the expanded target storage space.