Patent ID: 8131671

Claim:
A computer-implemented method for migrating files from a source file system to a target file system comprising: selecting a level of granularization for a virtual file layer, wherein selecting the level of granularization includes selecting a size for the virtual file layer; selecting a source file containing a plurality of data from the source file system in a accordance with a user configurable policy; responsive to selecting the source file, creating a target file in the target file system; responsive to selecting the source file and creating the target file, mounting the virtual file layer over the source file and the target file; migrating the plurality of data from the source file to the target file; and responsive to a completion of migration of the plurality of data from the source file to the target file, removing the virtual file layer from the source file and the target file; wherein the virtual file layer provides an uninterruptible migration path from the source file to the target file and reads data from and writes data to the source file and the target file during the migrating, wherein the target file system is one of: JFS, JFS2, or GPFS.