Effective handling of HSM migrated files and snapshots

A system for handling snapshots together with migrated files in a hierarchical storage management, said system comprising:

• a first-tier storage and a second-tier storage adapted for managing files, wherein said files are organized in a file system in said first-tier storage, wherein said file system is a managed file system;
• a processing unit comprising:
• a snapshot unit creating a snapshot of a portion of said files of said first-tier storage, and thereby creating a hidden directory in said file system;
• a deletion module deleting a file in said first-tier storage, wherein said file is a migrated file, wherein the migrated file is copied from the first-tier storage to the second-tier storage;
• and
• a movement unit moving a stub file relating to said file to be deleted in said first-tier storage to said hidden directory, wherein the stub file includes metadata attributes that provide a link to the migrated file located in the second-tier storage, wherein the link grants access to the migrated file.

A computer program product for handling snapshots together with migrated files in a hierarchical storage management, said computer program product comprising a computer readable storage medium having program instructions embodied therewith, said program instructions being executable by one or more computing systems to cause said one or more computing systems to:

• manage files using a first-tier storage and a second-tier storage, wherein said files are organized in a file system in said first-tier storage, wherein said file system is a managed file system;
• creating a snapshot of a portion of said files of said first-tier storage, and thereby creating a hidden directory in said file system;
• deleting a file in said first-tier storage, wherein said file is a migrated file, wherein the migrated file is copied from the first-tier storage to the second-tier storage;
• and
• moving a stub file relating to said file to be deleted in said first-tier storage to said hidden directory, wherein the stub file includes metadata attributes that provide a link to the migrated file located in the second-tier storage, wherein the link grants access to the migrated file.