Patent attributes
System and method for partial file migration in file systems by Hierarchical Storage Management (HSM) applications. Embodiments may provide an automated mechanism for HSM applications to partially migrate files by migrating the inactive parts of the files to offline storage while leaving the active parts of the files on disk and active in the file system. In embodiments, access information including timestamps may be recorded and maintained at the subfile level to enable detection of inactivity at the subfile level and hence partial file migration by migrating only the inactive parts of files. The parts of files may be extents, blocks, or ranges. The access information may be recorded and maintained in-memory only, in a separate file on disk, or in extent descriptors for the files.
