File deletion in storage devices based on the deletion priority rules

• US 10,176,182 B2
• Filed: 08/31/2015
• Issued: 01/08/2019
• Est. Priority Date: 08/31/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Adam, Constantin M., Rofrano, John J., Guo, Shang Q., Wu, Frederick Y.-F., Zeng, Sai
• Primary Examiner(s): Featherstone, Mark D
• Assistant Examiner(s): McQuitery, Diedra
• Application Number:
  US14/840,911
• Publication Number:
  US 20170060886A1
• Time in Patent Office: 1,226 Days
• CPC Class Codes: G06F 16/122 using management policies backup systems G06F11/1446; file migration policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/125 characterised by the use of retention policies retention policies for HSM systems G06F16/185
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652

Abstract

Deleting files may include identifying files stored in a storage device to delete based on one or more deletion rules. The identified files are categorized into at least a first group and a second group. Deletion of files may be triggered based on a free space threshold. Deletion of files in the first group may be triggered. If the free space threshold is not met by deleting the files in the first group, deletion of files in the second group is triggered based on one or more of prioritization and cost optimization.

Claims

1. A computer-implemented method of deleting files, comprising executing on one or more processors the steps of:

identifying files stored in a storage device to delete based on one or more deletion rules;

categorizing the identified files into at least a first group and a second group;

triggering deletion of files based on a free space threshold, wherein the triggering deletion of files comprises;

deleting the files in the first group;

determining whether the free space threshold is met by deleting the files in the first group;

responsive to determining that the free space threshold is not met by deleting the files in the first group, triggering deletion of files in the second group based on at least a cost optimization, wherein the cost optimization comprises solving an objective function subject to a constraint, the objective function comprising minimizing a sum, over the files in the second group, of a product of a decision variable of whether a file in the second group is deleted or not deleted, a cost for recovery of the file in the second group, and a probability that the file in the second group will be needed within a predetermined time period, and the constraint comprising a sum, over the files in the second group, of a product of the decision variable of whether the file in the second group is deleted or not deleted and the file'"'"'s size of the file in the second group is greater than or equal to the free space threshold, and marking the files in the second group indicated by the decision variable for deletion.

2. The method of claim 1, further comprising:

setting a highest deletion priority to the files in the first group.

3. The method of claim 1, wherein the triggering deletion of files comprises deleting all files marked for deletion in a batch mode.

4. The method of claim 1, wherein the free space threshold is configurable based on one or more of a computer device coupled to the storage device, size of a random access memory (RAM) associated with the computer device, size of the storage device, one or more applications deployed on the computer device.

5. The method of claim 1, further comprising determining a prioritization for deleting files in the second group based on one or more of file type, last date modified, file size, file dependency, number of file copies, and number of file versions.

6. The method of claim 1, wherein the method is performed automatically and periodically.

7. The method of claim 1, further comprising periodically marking the files in the second group for deletion based on one or more of the prioritization and cost optimization.

8. A system for deleting files, comprising:

a storage device; and

one or more processors operable to identify files stored in the storage device to delete based on one or more deletion rules,

one or more of the processors further operable to categorize the identified files into at least a first group and a second group;

one or more of the processors further operable to trigger deletion of files based on a free space threshold, wherein one or more of the processors triggers deletion of files by deleting the files in the first group, determining whether the free space threshold is met by deleting the files in the first group, and responsive to determining that the free space threshold is not met by deleting the files in the first group, triggering deletion of files in the second group based on at least a cost optimization, wherein one or more of the processors determines the cost optimization by solving an objective function subject to a constraint, the objective function comprising minimizing a sum, over the files in the second group, of a product of a decision variable of whether a file in the second group is deleted or not deleted, a cost for recovery of the file in the second group, and a probability that the file in the second group will be needed within a predetermined time period, and the constraint comprising a sum, over the files in the second group, of a product of the decision variable of whether the file in the second group is deleted or not deleted and the file'"'"'s size of the file in the second group is greater than or equal to the free space threshold, and marking the files in the second group indicated by the decision variable for deletion.

9. The system of claim 8, wherein one or more of the processors sets a highest deletion priority to the files in the first group.

10. The system of claim 8, wherein the free space threshold is configurable and is based on one or more of a computer device coupled to the storage device, size of a random access memory (RAM) associated with the computer device, size of the storage device, one or more applications deployed on the computer device.

11. The system of claim 8, wherein one or more of the processors determines a prioritization for deleting files in the second group based on one or more of file type, last date modified, file size, file dependency, number of file copies, and number of file versions.

12. A non-transitory computer readable storage medium storing a program of instructions executable by a machine to perform a method of deleting files, the method comprising:

identifying files stored in a storage device to delete based on one or more deletion rules;

categorizing the identified files into at least a first group and a second group;

triggering deletion of files based on a free space threshold, wherein the triggering deletion of files comprises;

deleting the files in the first group;

determining whether the free space threshold is met by deleting the files in the first group;

responsive to determining that the free space threshold is not met by deleting the files in the first group, triggering deletion of files in the second group based on at least a cost optimization, wherein the cost optimization comprises solving an objective function subject to a constraint, the objective function comprising minimizing a sum, over the files in the second group, of a product of a decision variable of whether a file in the second group is deleted or not deleted, a cost for recovery of the file in the second group, and a probability that the file in the second group will be needed within a predetermined time period, and the constraint comprising a sum, over the files in the second group, of a product of the decision variable of whether the file in the second group is deleted or not deleted and the file'"'"'s size of the file in the second group is greater than or equal to the free space threshold, and marking the files in the second group indicated by the decision variable for deletion.

13. The non-transitory computer readable storage medium of claim 12, wherein the method further comprises setting a highest deletion priority to the files in the first group.

14. The non-transitory computer readable storage medium of claim 12, wherein the method further comprises determining a prioritization for deleting files in the second group based on one or more of file type, last date modified, file size, file dependency, number of file copies, and number of file versions.

15. The non-transitory computer readable storage medium of claim 12, wherein the method is performed automatically and periodically.

16. The non-transitory computer readable storage medium of claim 12, wherein the method further comprises periodically marking the files in the second group for deletion based on one or more of the prioritization and cost optimization.