DATA MIGRATION BETWEEN A RAID MEMORY AND A DISPERSED STORAGE NETWORK MEMORY

• US 20110213929A1
• Filed: 12/31/2010
• Published: 09/01/2011
• Est. Priority Date: 02/27/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Resch, Jason K., Markison, Timothy W., Grube, Gary W., Baptist, Andrew
• Granted Patent: US 8,850,113 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; 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], H04L67/1097
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• 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
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• 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 method begins by a processing module determining whether to convert data between a redundant array of independent disks (RAID) format and a dispersed storage network (DSN) format. The method continues with the processing module retrieving the data from a RAID memory to produce retrieved RAID data when the data is to be converted from the RAID format to the DSN format. The method continues with the processing module converting stripe-block data of the retrieved RAID data into a plurality of sets of encoded data slices and outputting the plurality of sets of encoded data slices to at least one of the RAID memory and a DSN memory for storage therein.

Claims

1. A method comprises:

determining whether to convert data between a redundant array of independent disks (RAID) format and a dispersed storage network (DSN) format;

when the data is to be converted from the RAID format to the DSN format, retrieving the data from the RAID memory to produce retrieved RAID data;

converting stripe-block data of the retrieved RAID data into a plurality of sets of encoded data slices; and

outputting the plurality of sets of encoded data slices to at least one of the RAID memory and a DSN memory for storage therein.

2. The method of claim 1, wherein the determining whether to convert the data from the RAID format to the DSN format comprises at least one of:

determining when an access frequency of the data compares favorably to an access threshold;

determining when an access speed for the data compares favorably to an access speed threshold;

determining when a capacity of the RAID memory compares favorably to a capacity threshold; and

receiving a data conversion command.

3. The method of claim 1 further comprises:

sending a delete data message to the RAID memory requesting the RAID memory to delete the data.

4. The method of claim 1 further comprises:

sending an overwrite message to the RAID memory such that the RAID memory overwrites the data with at least some of the plurality of sets of encoded data slices.

5. The method of claim 1, wherein the outputting the plurality of sets of encoded data slices comprises:

outputting at least one set of the plurality of sets of encoded data slices to the DSN memory; and

outputting at least one other set of the plurality of sets of encoded data slices to a RAID memory.

6. The method of claim 1, wherein the outputting the plurality of sets of encoded data slices further comprises:

outputting a sub-set of each of the plurality of sets of encoded data slices to the DSN memory; and

outputting remaining encoded data slices of each of the plurality of sets of encoded data slices to a RAID memory.

7. The method of claim 1 further comprises:

when the data is to be converted from the DSN format to the RAID format, retrieving the plurality of sets of encoded data slices from the DSN memory;

decoding the plurality of sets of encoded data slices to produce recovered DSN data;

converting the DSN data into RAID data; and

outputting the RAID data to the RAID memory.

8. A computer comprises:

an interface;

a memory; and

a processing module operable to;

determine whether to convert data between a redundant array of independent disks (RAID) format and a dispersed storage network (DSN) format;

retrieve, via the interface, the data from the RAID memory to produce retrieved RAID data when the data is to be converted from the RAID format to the DSN format;

convert stripe-block data of the retrieved RAID data into a plurality of sets of encoded data slices; and

output, via the interface, the plurality of sets of encoded data slices to at least one of the RAID memory and a DSN memory for storage therein.

9. The computer of claim 8, wherein the processing module functions to determine whether to convert the data from the RAID format to the DSN format by at least one of:

determining when an access frequency of the data compares favorably to an access threshold;

determining when an access speed for the data compares favorably to an access speed threshold;

determining when a capacity of the RAID memory compares favorably to a capacity threshold; and

receiving, via the interface, a data conversion command.

10. The computer of claim 8, wherein the processing module further functions to:

send, via the interface, a delete data message to the RAID memory requesting the RAID memory to delete the data.

11. The computer of claim 8, wherein the processing module further functions to:

send, via the interface, an overwrite message to the RAID memory such that the RAID memory overwrites the data with at least some of the plurality of sets of encoded data slices.

12. The computer of claim 8, wherein the processing module functions to output the plurality of sets of encoded data slices by:

outputting, via the interface, at least one set of the plurality of sets of encoded data slices to the DSN memory; and

outputting, via the interface, at least one other set of the plurality of sets of encoded data slices to a RAID memory.

13. The computer of claim 8, wherein the processing module further functions to output the plurality of sets of encoded data slices by:

outputting, via the interface, a sub-set of each of the plurality of sets of encoded data slices to the DSN memory; and

outputting, via the interface, remaining encoded data slices of each of the plurality of sets of encoded data slices to a RAID memory.

14. The computer of claim 8, wherein the processing module further functions to:

retrieve, via the interface, the plurality of sets of encoded data slices from the DSN memory when the data is to be converted from the DSN format to the RAID format;

decode the plurality of sets of encoded data slices to produce recovered DSN data;

convert the DSN data into RAID data; and

output, via the interface, the RAID data to the RAID memory.