EXTERNAL HEALING MODE FOR A DISPERSED STORAGE NETWORK MEMORY

• US 20170168899A1
• Filed: 02/28/2017
• Published: 06/15/2017
• Est. Priority Date: 05/29/2015
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Dhuse, Greg R., Iljazi, Ilir
• Granted Patent: US 10,789,128 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/008 Reliability or availability analysis
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1088 Reconstruction on already foreseen single or plurality of spare disks
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/1612 where the redundant component is persistent storage
• CPC Class Codes: G06F 2201/81 Threshold
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• 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

A computing device includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and a processing module operably coupled to the interface and memory such that the processing module, when operable within the computing device based on the operational instructions, is configured to perform various operations. Based on a detected storage error, the computing device is configured to determine availability status of encoded data slices (EDSs) within a set of EDSs. When at least a threshold number of EDSs are available, the computing device is configured to initiate a rebuilding function to abate the detected storage error. When less than the threshold number of EDSs are available, the computing device is configured to initiate a slice repair function to at least one storage unit (SU) to abate the detected storage error.

Claims

1. A computing device comprising:

an interface configured to interface and communicate with a dispersed or distributed storage network (DSN);

memory that stores operational instructions; and

a processing module operably coupled to the interface and to the memory, wherein the processing module, when operable within the computing device based on the operational instructions, is configured to;

based on a detected storage error, determine availability status of encoded data slices (EDSs) within a set of EDSs stored within one or more storage units (SUs) within the DSN, wherein a data object is segmented into a plurality of data segments, wherein a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce the set of EDSs;

when at least a threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiate a rebuilding function to abate the detected storage error; and

when less than the threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiate a slice repair function to at least one SU of the one or more SUs to abate the detected storage error.

2. The computing device of claim 1, wherein the processing module, when operable within the computing device based on the operational instructions, is further configured to initiate the rebuilding function to abate the detected storage error including to:

facilitate the rebuilding function using the at least a threshold number of EDSs of the set of EDSs to produce a recovered data segment;

dispersed error encode the recovered data segment to produce one or more rebuilt EDSs; and

facilitate replacement of one or more missing EDSs within the set of EDS with the one or more rebuilt EDSs within the one or more SUs within the DSN.

3. The computing device of claim 1, wherein the processing module, when operable within the computing device based on the operational instructions, is further configured to initiate the slice repair function to the at least one SU of the one or more SUs to abate the detected storage error including to:

issue a slice repair request to at least one SU of the one or more SUs to direct the at least one SU of the one or more SUs to produce at least one repaired EDS; and

for the at least one repaired EDS that is successfully generated by the at least one SU of the one or more SUs, facilitate replacement of an unavailable EDSs with the repaired EDS that is produced by the at least one SU of the one or more SUs.

4. The computing device of claim 3 further comprising:

the at least one SU of the one or more SUs configured to perform at least one of a filesystem repair operation, a memory recovery technique, or an individual data block rebuilding of an EDS to produce the repaired EDS based on the slice repair request received by the SU of the one or more SUs that directs the SU of the one or more SUs to produce the repaired EDS.

5. The computing device of claim 1, wherein:

the set of EDSs is of pillar width;

the set of EDSs are distributedly stored among a plurality of SUs within the DSN;

the threshold number of EDSs includes at least one of a decode threshold number of EDSs, a read threshold number of EDSs, or a write threshold number of EDSs;

the decode threshold number of EDSs are needed to recover the data segment;

the read threshold number of EDSs provides for reconstruction of the data segment; and

the write threshold number of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN.

6. The computing device of claim 1, wherein the computing device is located at a first premises that is remotely located from at least one SU of the one or more SUs within the DSN.

7. The computing device of claim 1 further comprising:

an integrity processing unit, a SU of the one or more SUs within the DSN, a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

8. The computing device of claim 1, wherein the DSN includes at least one of a wireless communication system, a wire lined communication systems, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).

9. A computing device comprising:

an interface configured to interface and communicate with a dispersed or distributed storage network (DSN);

memory that stores operational instructions; and

a processing module operably coupled to the interface and to the memory, wherein the processing module, when operable within the computing device based on the operational instructions, is configured to;

based on a detected storage error, determine availability status of encoded data slices (EDSs) within a set of EDSs stored within one or more storage units (SUs) within the DSN, wherein a data object is segmented into a plurality of data segments, wherein a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce the set of EDSs;

when at least a threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiate a rebuilding function to abate the detected storage error including to;

facilitate the rebuilding function using the at least a threshold number of EDSs of the set of EDSs to produce a recovered data segment;

dispersed error encode the recovered data segment to produce one or more rebuilt EDSs; and

facilitate replacement of one or more missing EDSs within the set of EDS with the one or more rebuilt EDSs within the one or more SUs within the DSN; and

when less than the threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiate a slice repair function to at least one SU of the one or more SUs to abate the detected storage error including to;

issue a slice repair request to at least one SU of the one or more SUs to direct the at least one SU of the one or more SUs to produce at least one repaired EDS; and

for the at least one repaired EDS that is successfully generated by the at least one SU of the one or more SUs, facilitate replacement of an unavailable EDSs with the repaired EDS that is produced by the at least one SU of the one or more SUs.

10. The computing device of claim 9 further comprising:

the at least one SU of the one or more SUs configured to perform at least one of a filesystem repair operation, a memory recovery technique, or an individual data block rebuilding of an EDS to produce the repaired EDS based on the slice repair request received by the SU of the one or more SUs that directs the SU of the one or more SUs to produce the repaired EDS.

11. The computing device of claim 9, wherein:

the set of EDSs is of pillar width;

the set of EDSs are distributedly stored among a plurality of SUs within the DSN;

the threshold number of EDSs includes at least one of a decode threshold number of EDSs, a read threshold number of EDSs, or a write threshold number of EDSs;

the decode threshold number of EDSs are needed to recover the data segment;

the read threshold number of EDSs provides for reconstruction of the data segment; and

the write threshold number of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN.

12. The computing device of claim 9 further comprising:

an integrity processing unit, a SU of the one or more SUs within the DSN, a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

13. The computing device of claim 9, wherein the DSN includes at least one of a wireless communication system, a wire lined communication systems, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).

14. A method for execution by a computing device, the method comprising:

based on a detected storage error, determining availability status of encoded data slices (EDSs) within a set of EDSs stored within one or more storage units (SUs) within a dispersed or distributed storage network (DSN), wherein a data object is segmented into a plurality of data segments, wherein a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce the set of EDSs;

when at least a threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiating, via an interface configured to interface and communicate with the DSN, a rebuilding function to abate the detected storage error; and

when less than the threshold number of EDSs of the set of EDSs are available based on the availability status that is determined, initiating, via the interface configured to interface and communicate with the DSN, a slice repair function to at least one SU of the one or more SUs to abate the detected storage error.

15. The method of claim 14 further comprising initiating the rebuilding function to abate the detected storage error including:

facilitating the rebuilding function using the at least a threshold number of EDSs of the set of EDSs to produce a recovered data segment;

dispersed error encoding the recovered data segment to produce one or more rebuilt EDSs; and

facilitating replacement of one or more missing EDSs within the set of EDS with the one or more rebuilt EDSs within the one or more SUs within the DSN.

16. The method of claim 14 further comprising initiating the slice repair function to the at least one SU of the one or more SUs to abate the detected storage error including:

issuing a slice repair request to at least one SU of the one or more SUs to direct the at least one SU of the one or more SUs to produce at least one repaired EDS; and

for the at least one repaired EDS that is successfully generated by the at least one SU of the one or more SUs, facilitating replacement of an unavailable EDSs with the repaired EDS that is produced by the at least one SU of the one or more SUs.

17. The method of claim 16 further comprising:

the at least one SU of the one or more SUs configured to perform at least one of a filesystem repair operation, a memory recovery technique, or an individual data block rebuilding of an EDS to produce the repaired EDS based on the slice repair request received by the SU of the one or more SUs that directs the SU of the one or more SUs to produce the repaired EDS.

18. The method of claim 14, wherein:

the set of EDSs is of pillar width;

the set of EDSs are distributedly stored among a plurality of SUs within the DSN;

the threshold number of EDSs includes at least one of a decode threshold number of EDSs, a read threshold number of EDSs, or a write threshold number of EDSs;

the decode threshold number of EDSs are needed to recover the data segment;

the read threshold number of EDSs provides for reconstruction of the data segment; and

the write threshold number of EDSs provides for a successful transfer of the set of EDSs from a first at least one location in the DSN to a second at least one location in the DSN.

19. The method of claim 14, wherein the computing device includes an integrity processing unit, a SU of the one or more SUs within the DSN, a wireless smart phone, a laptop, a tablet, a personal computers (PC), a work station, or a video game device.

20. The method of claim 14, wherein the DSN includes at least one of a wireless communication system, a wire lined communication systems, a non-public intranet system, a public internet system, a local area network (LAN), or a wide area network (WAN).