Facilitation of data deletion for distributed erasure coding

• US 10,284,234 B1
• Filed: 07/19/2017
• Issued: 05/07/2019
• Est. Priority Date: 07/19/2017
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Danilov, Mikhail, Rakulenko, Alexander
• Primary Examiner(s): Tabone, Jr., John J
• Application Number:
  US15/654,109
• Time in Patent Office: 657 Days
• Field of Search: 714752, 714764, 714766-770, 714773, 714784, 714786
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 11/1032 Simple parity
• CPC Class Codes: G06F 11/2056 by mirroring
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G06F 2221/2111 Location-sensitive, e.g. geographical location, GPS
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: H03M 13/373 with erasure correction and erasure determination, e.g. for packet loss recovery or setting of erasures for the decoding of Reed-Solomon codes

Abstract

Although a distributed storage device can recover data from multiple failures this process produces excessive inter-zone network traffic when a chunk with user data is deleted. This disclosure employs an un-encoding erasure coding and partial coding chunks to facilitate data deletes while reducing inter-zone network traffic. Therefore a data chunk representative of partitioned disk space associated with a first zone of a data store can be determined to be marked for deletion. Consequently, the data chunk can be copied, resulting in a copied data chunk, to a second zone of the data store associated with a coding chunk comprising the data chunk. Based on the copied data chunk and the coding chunk, a partial coding chunk can be generated via un-encoding, wherein the partial coding chunk is a subset of the coding chunk.

Claims

1. A method, comprising:

determining, by a system comprising a processor, a data chunk, of data chunks representative of partitioned disk space associated with a first zone of a data store, is marked for deletion;

in response to the determining, copying, by the system, the data chunk, resulting in a copied data chunk, to a second zone of the data store associated with a coding chunk comprising the data chunks; and

based on the copied data chunk and the coding chunk, generating, by the system, a partial coding chunk, wherein the partial coding chunk is a subset of the coding chunk.

2. The method of claim 1, wherein the partial coding chunk does not comprise the data chunk of the coding chunk.

3. The method of claim 1, wherein the copied data chunk is a first copied data chunk, wherein the coding chunk is a first coding chunk, wherein the partial coding chunk is a first partial coding chunk, and wherein the method further comprises:

copying, by the system, a second copied data chunk, to a third zone associated with a second coding chunk comprising the data chunk; and

based on the second copied data chunk and the second coding chunk, generating, by the system, a second partial coding chunk.

4. The method of claim 1, further comprising:

in response to the generating the partial coding chunk, deleting, by the system, the coding chunk associated with the second zone.

5. The method of claim 1, further comprising:

in response to the generating the partial coding chunk, deleting, by the system, the data chunk associated with the first zone.

6. The method of claim 1, wherein the data chunk is a first data chunk, and further comprising:

generating, by the system, a second data chunk associated with the first zone to replace the first data chunk.

7. The method of claim 6, wherein the copied data chunk is a first copied data chunk, and further comprising:

copying, by the system, the second data chunk to the second zone to complete the partial coding chunk, resulting in a second copied data chunk.

8. A system, comprising:

a processor; and

a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising;

receiving an indication that a data chunk, of data chunks representative of apportioned disk space associated with a first zone of a data store, is to be deleted;

in response to the receiving, sending a copy of the data chunk to a second zone associated with a coding chunk comprising the data chunks; and

based on the copy of the data chunk and the coding chunk, generating a partial coding chunk without the data chunk, wherein the partial coding chunk is a subset of the coding chunk.

9. The system of claim 8, wherein the operations further comprise:

distributing the partial coding chunk across zones to replace the coding chunk.

10. The system of claim 9, wherein the operations further comprise:

in response to the distributing, deleting the copy of the data chunk during an un-encoding operation.

11. The system of claim 8, wherein the partial coding chunk is generated, by a distributed storage device, from a complete coding chunk of the second zone.

12. The system of claim 8, wherein the generating comprises an un-encoding operation for deletion of the data chunk of the first zone.

13. The system of claim 8, wherein the operations further comprise:

in response to the second zone storing the partial coding chunk, deleting the data chunk to reduce inter-zone traffic between the first zone and the second zone.

14. The system of claim 8, wherein the operations further comprise:

in response to the second zone storing the partial coding chunk, deleting the copy to reduce inter-zone traffic between the first zone and the second zone.

15. The system of claim 8, wherein the operations further comprise:

in response to the second zone storing the partial coding chunk, deleting the coding chunk to reduce inter-zone traffic between the first zone and the second zone.

16. A computer-readable storage medium comprising instructions that, in response to execution, cause a server device comprising a processor to perform operations, comprising:

facilitating a request to delete a data chunk of data chunks, wherein the data chunk is associated with a first zone of a data store;

in response to the facilitating, facilitating generating a copy of the data chunk to be sent to a second zone associated with a coding chunk, wherein the coding chunk comprises the data chunks;

facilitating sending the copy of the data chunk to the second zone; and

based on an indication that the copy of the data chunk has been determined to have been received by the second zone, generating a partial coding chunk, wherein the partial coding chunk is different than the coding chunk.

17. The computer-readable storage medium of claim 16, wherein the generating the partial coding chunk comprises extracting the data chunk from the coding chunk.

18. The computer-readable storage medium of claim 17, wherein the operations further comprise:

in response to the generating the partial coding chunk, deleting the data chunk to reduce inter-zone traffic between the first zone and the second zone.

19. The computer-readable storage medium of claim 16, wherein the operations further comprise:

in response to the generating the partial coding chunk, deleting the copy of the data chunk and the coding chunk to reduce inter-zone traffic between the first zone and the second zone.

20. The computer-readable storage medium of claim 16, wherein the generating the partial coding chunk comprises an un-encoding operation, and wherein the un-encoding operation is performed by zones concurrently.