Systems and methods for recovering electronic information from a storage medium

• US 7,472,238 B1
• Filed: 11/07/2005
• Issued: 12/30/2008
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Gokhale, Parag, Wang, Yu, Kottomtharayil, Rajiv, Lu, Yanhui, Lu, Jun
• Primary Examiner(s): PATEL, HETUL B
• Application Number:
  US11/269,515
• Time in Patent Office: 1,149 Days
• Field of Search: 711/159
• US Class Current: 711/159
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00
• CPC Class Codes: G06F 2201/815 Virtual
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0686 Libraries, e.g. tape libraries, jukebox
• CPC Class Codes: H04L 41/046 comprising network management agents or mobile agents therefor
• CPC Class Codes: H04L 41/22 comprising specially adapted graphical user interfaces [GUI]
• CPC Class Codes: H04L 41/40 using virtualisation of network functions or resources, e.g. SDN or NFV entities
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

In one embodiment of the invention, a method is provided for retrieving certain electronic information previously stored on certain storage media after a threshold set in the storage retention criteria has been exceeded in an electronic information storage system that stores electronic information on storage media in accordance with a storage retention criteria is provided. The method includes storing a record in a memory associated with a system manager that assigns the storage retention criteria to the certain electronic data, designating the storage media available for overwrite after the threshold set in the storage retention policy has been exceeded, identifying the certain storage media available for overwrite, and retrieving information from the certain media after the threshold set in the storage retention policy has been exceeded.

Claims

1. A method for preserving location information related to data stored on removable storage media comprising:

writing a section of data to a removable storage medium, wherein writing the section of data includes writing the section of data in accordance with a data retention policy that defines a minimum time period in which the section of data cannot be overwritten;

updating an index associated with the data to include location information related to the section of data that indicates the section of data is stored on a certain portion of the removable storage medium; and

after the minimum time period lapses,

designating the certain portion of the removable storage medium that contains the section of data is available for overwrite; and

deleting the location information related to the section of data from the updated index only after the section of data corresponding to the location information is overwritten.

2. The method of claim 1, further comprising:

storing the location information related to the section of data to an index separate from the updated index, wherein the index separate from the updated index includes location information related to data that has been partially overwritten.

3. The method of claim 1 wherein the portion of the section of data overwritten is the entire section of data.

4. The method of claim 1, further comprising:

retrieving, using the location information from the updated index, at least some of the section of data from the removable storage medium after the minimum time period has lapsed.

5. A method of selectively retrieving data from storage media in a storage system comprising:

storing data on a plurality of storage media pursuant to at least one storage policy;

retaining the data on the plurality of storage media in accordance with the at least one storage policy;

designating portions of at least some of the storage media available for overwrite when data stored on the portions of the at least some of the storage media has exceed a threshold established in the storage policy; and

maintaining records regarding the data that has exceeded the threshold in the storage policy, wherein maintaining records regarding the data that has exceeded the threshold in the storage policy includes preventing erasure of the maintained records before the data that has exceeded the threshold is overwritten.

6. The method of claim 5 further comprising retrieving data from portions of the at least some storage media.

7. The method of claim 5 wherein the storage media available for overwrite are assigned to a spare media pool.

8. The method of claim 7 further comprising displaying on a display screen the storage media assigned to the spare media pool.

9. The method of claim 5 further comprising providing a user interface that allows a user to search the plurality of storage media for data that has exceeded a threshold established in the storage policy and not overwritten.

10. The method of claim 5 further comprising providing a user interface that allows a user to search for and display an indicia regarding the storage media that contains data that has exceeded a threshold established in the storage policy and not overwritten.

11. The method of claim 10 wherein the indicia includes information regarding the physical location of the storage media.

12. The method of claim 5 further comprising preferentially overwriting data stored on the storage media based on data age.

13. The method of claim 5 further comprising preferentially overwriting data stored on the storage media based on data type.

14. The method of claim 5 further comprising preferentially overwriting data stored on the storage media based on user defined criteria.

15. The method of claim 5 further comprising displaying on a display screen the storage media assigned to the save pool.

16. A system for restoring data stored on removable storage media, comprising:

a data storage component, wherein the data storage component stores data to removable storage media;

an indexing component, wherein the indexing component creates information related to the storage of the data to the removable storage media;

a storage policy component, wherein the storage policy component assigns a time period in which to maintain the data stored to the removable storage media; and

a data restoration component, wherein the data restoration component is configured to use the information related to the storage of the data to the removable storage media (1) to retrieve the data when a time of retrieval is within the time period in which to maintain the data, and (2) to retrieve the data when a time of retrieval is outside of the time period in which to maintain the data but before the data is overwritten;

wherein the information related to the storage of the data to the removable storage media is maintained until the data corresponding to the information is overwritten.

17. A method of restoring data stored on a physical storage medium, the method comprising:

receiving a request to restore data stored on a physical storage medium, wherein the request is received after a time period in which to maintain the data stored on the physical storage medium has expired but before the data stored on the physical storage medium is overwritten;

locating the physical storage medium that contains the data, wherein locating the physical storage medium includes identifying location information related to the stored data and stored in an index associated with the stored data, wherein the location information related to the stored data is maintained in the index associated with the stored data until the stored data is overwritten; and

retrieving the stored data from the physical storage medium using the identified location information.