Prioritizing read locations based on an error history

• US 10,051,057 B2
• Filed: 12/12/2017
• Issued: 08/14/2018
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Cocagne, Thomas D., Resch, Jason K., Dhuse, Greg R.
• Primary Examiner(s): Bradley, Matthew
• Application Number:
  US15/839,814
• Publication Number:
  US 20180103106A1
• Time in Patent Office: 245 Days
• Field of Search: 711103
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• 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]
• CPC Class Codes: H04L 67/535 Tracking the activity of the user network monitoring arrangements H04L43/00; recording of computer activity G06F11/34

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 processing circuitry. The processing circuitry is configured to execute the operational instructions to perform various operations and functions. The computing device identifies slice error(s) associated with first storage unit(s) (SU(s)) of a first storage set that distributedly store a set of encoded data slices (EDSs) and second SU(s) of a second storage set. The computing device determines usage priority level(s) of the first SU(s) or the second SU(s) based on the slice error(s) and produces a selected storage set from the first SU(s) and the second SU(s) based on a more favorable usage priority level of the usage priority level(s) and facilitates execution of data access to at least the decode threshold number of EDSs based on the selected storage set.

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

processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to;

identify one or more slice errors associated with first one or more storage units (SUs) of a first storage set that distributedly store a set of encoded data slices (EDSs) associated with a data object and second one or more SUs of a second storage set, wherein the 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, wherein a decode threshold number of EDSs are needed to recover the data segment;

determine one or more usage priority levels of at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set based on the one or more slice errors that are detected, wherein at least one of the second one or more SUs of the second storage set also stores at least one EDS of the set of EDSs;

produce a selected storage set from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set based on a more favorable usage priority level of the one or more usage priority levels of the at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set; and

facilitate execution of data access to at least the decode threshold number of EDSs based on the selected storage set.

2. The computing device of claim 1, wherein the processing circuitry is further configured to execute the operational instructions to:

produce the selected storage set that includes a read threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a read data access, wherein a read threshold number of EDSs provides for reconstruction of the data segment.

3. The computing device of claim 1, wherein the processing circuitry is further configured to execute the operational instructions to:

produce the selected storage set that includes a write threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a write data access, wherein a 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.

4. The computing device of claim 1, wherein the processing circuitry is further configured to execute the operational instructions to:

receive status information associated with the first one or more SUs of the first SU set, wherein the status information includes an indication of EDS availability by a slice name and a revision level; and

compare the status information to identify the one or more slice errors, wherein the one or more slice errors includes at least one of a missing EDS, a missing delete marker, or a corrupted EDS.

5. The computing device of claim 1, wherein:

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

a 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;

the set of EDSs is of pillar width and includes a pillar number of EDSs;

each of the decode threshold number, the read threshold number, and the write threshold number is less than the pillar number; and

the write threshold number is greater than or equal to the read threshold number that is greater than or equal to the decode threshold number.

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

7. The computing device of claim 1 further comprising:

a SU of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set 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 system, 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

processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to;

identify one or more slice errors associated with first one or more storage units (SUs) of a first storage set that distributedly store a set of encoded data slices (EDSs) associated with a data object and second one or more SUs of a second storage set, wherein the 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, wherein a decode threshold number of EDSs are needed to recover the data segment;

determine one or more usage priority levels of at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set based on the one or more slice errors that are detected, wherein at least one of the second one or more SUs of the second storage set also stores at least one EDS of the set of EDSs;

produce a selected storage set from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set based on a more favorable usage priority level of the one or more usage priority levels of the at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set including to;

produce the selected storage set that includes a read threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a read data access, wherein a read threshold number of EDSs provides for reconstruction of the data segment; and

produce the selected storage set that includes a write threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a write data access, wherein a 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; and

facilitate execution of data access to at least one of the decode threshold number of EDSs, read threshold number of EDSs, or the write threshold number of EDSs based on the selected storage set.

10. The computing device of claim 9, wherein the processing circuitry is further configured to execute the operational instructions to:

receive status information associated with the first one or more SUs of the first SU set, wherein the status information includes an indication of EDS availability by a slice name and a revision level; and

compare the status information to identify the one or more slice errors, wherein the one or more slice errors includes at least one of a missing EDS, a missing delete marker, or a corrupted EDS.

11. The computing device of claim 9, wherein:

the set of EDSs is of pillar width and includes a pillar number of EDSs;

each of the decode threshold number, the read threshold number, and the write threshold number is less than the pillar number; and

the write threshold number is greater than or equal to the read threshold number that is greater than or equal to the decode threshold number.

12. The computing device of claim 9 further comprising:

a SU of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set 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 system, 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:

identifying one or more slice errors associated with first one or more storage units (SUs) of a first storage set within a dispersed or distributed storage network (DSN) that distributedly store a set of encoded data slices (EDSs) associated with a data object and second one or more SUs of a second storage set within the DSN, wherein the 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, wherein a decode threshold number of EDSs are needed to recover the data segment;

determining one or more usage priority levels of at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set based on the one or more slice errors that are detected, wherein at least one of the second one or more SUs of the second storage set also stores at least one EDS of the set of EDSs;

producing a selected storage set from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set based on a more favorable usage priority level of the one or more usage priority levels of the at least one of the first one or more SUs of the first storage set or the second one or more SUs of the second storage set; and

facilitating, via an interface of the computing device that is configured to interface and communicate with the DSN, execution of data access to at least the decode threshold number of EDSs based on the selected storage set.

15. The method of claim 14 further comprising:

producing the selected storage set that includes a read threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a read data access, wherein a read threshold number of EDSs provides for reconstruction of the data segment.

16. The method of claim 14 further comprising:

producing the selected storage set that includes a write threshold number of SUs having the more favorable usage priority level from the first one or more SUs of the first storage set and the second one or more SUs of the second storage set when facilitation execution of a write data access, wherein a 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.

17. The method of claim 14 further comprising:

receiving status information associated with the first one or more SUs of the first SU set, wherein the status information includes an indication of EDS availability by a slice name and a revision level; and

comparing the status information to identify the one or more slice errors, wherein the one or more slice errors includes at least one of a missing EDS, a missing delete marker, or a corrupted EDS.

18. The method of claim 14, wherein:

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

a 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;

the set of EDSs is of pillar width and includes a pillar number of EDSs;

each of the decode threshold number, the read threshold number, and the write threshold number is less than the pillar number; and

the write threshold number is greater than or equal to the read threshold number that is greater than or equal to the decode threshold number.

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