Detecting and managing missing parents between primary and secondary data stores for content addressed storage

A content addressable data migration storage system for eliminating missing parent files that are not properly identified by secondary files, the storage system comprising:

• a primary storage device employing one of location addressable storage or content addressable storage and configured to store and detect a placeholder file, the detected placeholder file having replaced a data file that was migrated to a secondary storage device, the placeholder file including an offline reference with file identification data for identifying the placeholder file, the offline reference referencing the data file which is stored as a secondary file on the secondary storage device, wherein the offline address includes an address of the secondary file
• the secondary storage device employing content addressable storage and configured to store the secondary file, the secondary file including file identification data for identifying the secondary file, the file identification data of the secondary file related to the offline reference of the detected placeholder file, and the secondary file including at least one online reference to a referenced placeholder file on the primary storage device, wherein the detected placeholder file is properly identified if the detected placeholder file is the referenced placeholder file;
• and
• a policy engine server including a file management module for detecting that the detected placeholder file is not properly identified by the at least one online reference of the secondary file, wherein the detected placeholder file is a missing parent file that is eliminated from the primary storage device when not properly identified by the at least one online reference of the secondary file, wherein the file management module notifies a user of the policy engine server that the detected placeholder file is not properly identified by the at least one online reference of the secondary file.

In a distributed computer having a primary storage device, a secondary storage device and a policy engine server, the policy engine server being configured to manage migration of files between the primary storage device and the secondary storage device by migrating data files on the primary storage device to the secondary storage device and replacing the data files on the primary storage device with placeholder files, a computer program product configured to implement a method of locating and eliminating placeholder files within the primary storage device that are not properly referenced by secondary files stored on the secondary storage device, the computer program product comprising one or more computer readable media having stored thereon computer executable instructions that, when executed by a processor, cause the policy engine server to perform the following:

• identify a placeholder file on a primary storage device that has replaced a data file, the placeholder file including an offline reference to the data file stored as a secondary file on the secondary storage device, wherein the offline reference includes a content address of the secondary file;
• identify the secondary file on the secondary storage device using the content address of the secondary file included in the offline reference of the placeholder file;
• identify an online reference of the secondary file, wherein the online reference includes an address to a particular placeholder file stored on the primary storage device;
• determine that the placeholder file is a missing parent when the particular placeholder file is not the placeholder file;
• and
• notify a user of the policy engine server when the online reference of the secondary file does not properly reference the placeholder file or the file identification data of the placeholder file.