Systems and methods for recovering electronic information from a storage medium

• US 7,873,802 B2
• Filed: 11/24/2008
• Issued: 01/18/2011
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Wang, Yu, Lu, Yanhui, Lu, Jun, Gokhale, Parag, Kottomtharayil, Rajiv
• Primary Examiner(s): Patel; Hetul
• Application Number:
  US12/276,868
• Publication Number:
  US 20090172319A1
• Time in Patent Office: 785 Days
• Field of Search: None
• 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 middleware or OS functionality using virtual machines to implement generic software techniques for error detection or fault masking G06F11/1484
• 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 computer-implemented method for preserving location information related to data stored on removable data storage media, the method comprising:

writing a section of data to a removable data 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 during which the section of data cannot be overwritten;

updating an index to include location information 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, as available for overwrite, the certain portion of the removable data storage medium that contains the section of data; and

deleting from the updated index the location information related to the section of data only after at least a portion of the section of data 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. The method of claim 1 further comprising searching for and displaying information regarding identification of the storage media that contains the section of data.

6. The method of claim 1 wherein the section of data is overwritten after a threshold is exceeded.

7. A method for selectively retrieving data from data storage media, the method comprising:

storing data on multiple data storage media under at least one storage policy;

retaining the data on the multiple data storage media under the at least one storage policy, and for designating portions of at least some of the data storage media available for overwrite when data stored on the portions of the at least some of the data 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 the maintaining of 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.

8. The method of claim 7 further comprising retrieving data from portions of at least some of the data storage media.

9. The method of claim 7 wherein the data storage media available for overwrite are assigned to a spare media pool, and wherein the method further comprises displaying on a display screen the storage media assigned to the spare media pool.

10. The method of claim 7 further comprising providing a user interface that allows a user to search the multiple data storage media for data that has exceeded a threshold established in the storage policy and not overwritten.

11. The method of claim 7 further comprising providing a user interface that allows a user to search for and display an indicia regarding the data storage media that contain data that have exceeded a threshold established in the storage policy and not overwritten, and wherein the indicia includes information regarding a physical location of the data storage media.

12. The method of claim 7 further comprising preferentially overwriting data stored on the data storage media based on data age.

13. The method of claim 7 further comprising preferentially overwriting data stored on the data storage media based on data type or based on user defined criteria.

14. A method for recovering information from a storage media comprising:

writing a section of data to the storage media;

maintaining the section data on the storage media in accordance with a data retention policy;

designating at least a portion of the storage media that contains the section of data available for overwrite; and

continuing to maintain information regarding the section of data after the portion of the storage media is designated available for overwrite,

wherein the continuing to maintain information includes maintaining location information related to the section of data until at least a portion of the section of data corresponding to the location information is overwritten.

15. The method of claim 14 wherein the maintaining includes mainlining information regarding the section of data until the section of data is overwritten on the storage media.

16. The method of claim 14 further comprising retrieving at least some of the section of data from the storage media after the portion of the storage media is designated available for overwrite.

17. The method of claim 14 further comprising searching for and displaying an indication of the section of data on a displaying screen.

18. The method of claim 14 further comprising searching for and displaying information regarding identification of the storage media that contains the section of data.