Method and apparatus for dispersed storage memory device utilization

• US 10,209,903 B2
• Filed: 02/27/2013
• Issued: 02/19/2019
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Grube, Gary W., Markison, Timothy W.
• Primary Examiner(s): Dudek, Jr., Edward J
• Assistant Examiner(s): Verderamo, III, Ralph A
• Application Number:
  US13/779,469
• Publication Number:
  US 20130173987A1
• Time in Patent Office: 2,183 Days
• Field of Search: None
• 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 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/2053 where persistent mass storage functionality or persistent mass storage control functionality is redundant error detection or correction in information storage based on relative movement between record carrier and transducer G11B20/18
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/068 Hybrid storage device
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays

Abstract

A method begins with a processing module receiving data for storage. The method continues with the processing module determining storage metadata regarding storage requirements of the data. When the storage metadata includes a first type of storage mode, the method continues with the processing module determining a first error coding dispersal storage function; identifying first memory of DSN memory; encoding the data in accordance with the first error coding dispersal storage functions; and outputting the first encoded data slices to the first memory for storage therein. When the storage metadata includes a second type of storage mode, the method continues with the processing module determining a second error coding dispersal storage function; identifying second memory of a dispersed storage network (DSN) memory; encoding the data in accordance with the second error coding dispersal storage functions; and outputting the second encoded data slices to the second memory for storage therein.

Claims

1. A method for dispersed memory storage comprises:

receiving data for storage;

determining storage metadata regarding storage requirements of the data, wherein the storage metadata indicating one or more of;

a set of storage units of a plurality of sets of storage units of a dispersed storage network (DSN) memory, a storage mode of a plurality storage modes, and a corresponding one of a plurality of error coding dispersal storage functions;

encoding a data segment of the data in accordance with the corresponding one of a plurality of error coding dispersal storage functions to produce a set of encoded data slices;

when the storage metadata indicates a first type of storage mode of the plurality of storage modes;

outputting the set of encoded data slices to a first set of memory devices of the set of storage units for storage therein;

determining to change the storage mode from the first type of storage mode to a third type of storage mode of the plurality of storage modes after outputting the set of encoded data slices to the first set of memory devices of the set of storage units for storage; and

facilitating transfer of a subset of encoded data slices of the set of encoded data slices from storage in the first set of memory devices to storage in a subset of a second set of memory devices, wherein a set difference of the set of encoded data slices and the subset of the set of encoded data slices is greater than or equal to a decode threshold number of the one of the plurality of error coding dispersal storage functions;

when the storage metadata indicates a second type of storage mode of the plurality of storage modes;

outputting the set of encoded data slices to the second set of memory devices of the set of storage units of the DSN memory for storage therein; and

when the storage metadata indicates the third type of storage mode of the plurality of storage modes;

outputting the decode threshold number of encoded data slices of the set of encoded data slices to a subset of the first set of memory devices for storage therein; and

outputting remaining encoded data slices of the set of encoded data slices to the subset of the second set of memory devices for storage therein.

2. The method of claim 1 further comprising:

the first type of storage mode including a first time phase indicator that specifies a time period for initial storage of the data; and

the second type of storage mode including a second time phase that corresponds to a time period after the time period for initial storage of the data expires.

3. The method of claim 1 further comprises:

the first type of storage mode including an indication for customized data content; and

the second type of storage mode including an indication for generic data content.

4. The method of claim 1 further comprises:

the first type of storage mode including at least one of a first retrieval requirement and a first reliability requirement; and

the second type of storage mode including at least one of a second retrieval requirement and a second reliability requirement.

5. The method of claim 1, wherein the DSN memory comprises:

a plurality of DSN memory sites, wherein a one of the plurality of DSN memory sites includes a dispersed storage (DS) unit that includes a first type of memory devices and a second one of the plurality of DSN memory sites includes a DS unit that includes a second type of memory devices, wherein the first type of memory devices have different memory characteristics than the second type of memory devices, and wherein the memory characteristics includes one or more of;

speed of access, cost, reliability, availability, and capacity.

6. The method of claim 1, wherein the DSN memory comprises:

a plurality of dispersed storage (DS) units, wherein the first memory includes a first set of the plurality of DS units and the second memory includes a second set of the plurality of DS units, wherein one of the plurality of DS units includes a first type of memory devices and a second type of memory devices, wherein the first type of memory devices have different memory characteristics than the second type of memory devices, and wherein the one of the plurality of DS units is included in the first and second set of the plurality of DS units.

7. The method of claim 1, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining a time period of storage in the first set of memory devices has elapsed.

8. The method of claim 1, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining an update of the storage metadata has occurred.

9. The method of claim 1, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining a change of available memory devices has occurred.

10. The method of claim 1, further comprising, when the storage metadata indicates the third type of storage mode of the plurality of storage modes:

determining to change the storage mode from the third type of storage mode to the second type of storage mode after outputting the decode threshold number of encoded data slices of the set of encoded data slices to the subset of the first set of memory devices for storage and after outputting the remaining encoded data slices of the set of encoded data slices to the subset of the second set of memory devices for storage therein; and

facilitating transfer of the decode threshold number of encoded data slices of the decode threshold number of encoded data slices from storage in the first set of memory devices to storage in the second set of memory devices.

11. A computer comprises:

a dispersal memory interface; and

a processing module operable to;

receive data for storage;

determine storage metadata regarding storage requirements of the data, wherein the storage metadata indicating one or more of;

a set of storage units of a plurality of sets of storage units of a dispersed storage network (DSN) memory, a storage mode of a plurality storage modes, and a corresponding one of a plurality of error coding dispersal storage functions;

encode a data segment of the data in accordance with the corresponding one of a plurality of error coding dispersal storage functions to produce a set of encoded data slices;

when the storage metadata indicates a first type of storage mode of the plurality of storage modes;

output the set of encoded data slices to a first set of memory devices of the set of storage units for storage therein;

determine to change the storage mode from the first type of storage mode to a third type of storage mode of the plurality of storage modes after outputting the set of encoded data slices to the first set of memory devices of the set of storage units for storage; and

facilitate transfer of a subset of encoded data slices of the set of encoded data slices from storage in the first set of memory devices to storage in a subset of a second set of memory devices, wherein a set difference of the set of encoded data slices and the subset of the set of encoded data slices is greater than or equal to the decode threshold number of the one of the plurality of error coding dispersal storage functions;

when the storage metadata indicates a second type of storage mode of the plurality of storage modes;

output the set of encoded data slices to a second set of memory devices of the set of storage units for storage therein; and

when the storage metadata indicates the third type of storage mode of the plurality of storage modes;

output the decode threshold number of encoded data slices of the set of encoded data slices to a subset of the first set of memory devices for storage therein; and

output remaining encoded data slices of the set of encoded data slices to the subset of the second set of memory devices for storage therein.

12. The computer of claim 11 further comprises:

the first type of storage mode including a first time phase indicator that specifies a time period for initial storage of the data; and

the second type of storage mode including a second time phase that corresponds to a time period after the time period for initial storage of the data expires.

13. The computer of claim 11 further comprises:

the first type of storage mode including an indication for customized data content; and

the second type of storage mode including an indication for generic data content.

14. The computer of claim 11 further comprises:

the first type of storage mode including at least one of a first retrieval requirement and a first reliability requirement; and

the second type of storage mode including at least one of a second retrieval requirement and a second reliability requirement.

15. The computer of claim 11, wherein the DSN memory comprises:

a plurality of DSN memory sites, wherein a one of the plurality of DSN memory sites includes a dispersed storage (DS) unit that includes a first type of memory devices and a second one of the plurality of DSN memory sites includes a DS unit that includes a second type of memory devices, wherein the first type of memory devices have different memory characteristics than the second type of memory devices, and wherein the memory characteristics includes one or more of;

speed of access, cost, reliability, availability, and capacity.

16. The computer of claim 11, wherein the DSN memory comprises:

a plurality of dispersed storage (DS) units, wherein the first memory includes a first set of the plurality of DS units and the second memory includes a second set of the plurality of DS units, wherein one of the plurality of DS units includes a first type of memory devices and a second type of memory devices, wherein the first type of memory devices have different memory characteristics than the second type of memory devices, and wherein the one of the plurality of DS units is included in the first and second set of the plurality of DS units.

17. The computer of claim 11, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining a time period of storage in the first set of memory devices has elapsed.

18. The computer of claim 11, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining an update of the storage metadata has occurred.

19. The computer of claim 11, wherein determining to change the storage mode from the first type of storage mode to the third type of storage mode is based on determining a change of available memory devices has occurred.

20. The computer of claim 11, wherein the processing module, when the storage metadata indicates the third type of storage mode of the plurality of storage modes, is further operable to:

determine to change the storage mode from the third type of storage mode to the second type of storage mode after outputting the decode threshold number of encoded data slices of the set of encoded data slices to the subset of the first set of memory devices for storage and after outputting the remaining encoded data slices of the set of encoded data slices to the subset of the second set of memory devices for storage therein; and

facilitate transfer of the decode threshold number of encoded data slices of the decode threshold number of encoded data slices from storage in the first set of memory devices to storage in the second set of memory devices.