Slice migration in a dispersed storage network

• US 10,402,393 B2
• Filed: 08/01/2016
• Issued: 09/03/2019
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Dhuse, Greg R., Resch, Jason K.
• Primary Examiner(s): Channavajjala, Srirama
• Application Number:
  US15/225,476
• Publication Number:
  US 20160335308A1
• Time in Patent Office: 1,128 Days
• CPC Class Codes: G06F 11/1084 Degraded mode, e.g. caused by single or multiple storage removals or disk failures
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 16/214 Database migration support
• CPC Class Codes: G06F 16/2255 Hash tables
• CPC Class Codes: G06F 16/235 Update request formulation
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/9027 Trees
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions

Abstract

A method for use by a source storage unit of a dispersed storage network includes identifying a slice name corresponding to a slice to migrate from a source storage unit to a destination storage unit; sending the slice to migrate to the destination storage unit; generating a slice verification request and sending the slice verification request to the destination storage unit; receiving an integrity value from the destination storage unit; and determining when the integrity value compares favorably to the slice verification request. When the source storage unit determines that the integrity value compares favorably to the slice verification request, a slice name assignment associated with the slice name is updated and the slice is deleted from the source storage unit.

Claims

1. A method for execution by a source storage unit of a dispersed storage network that includes a processor, the method comprises:

identifying a slice name corresponding to a slice to migrate from the source storage unit to a destination storage unit;

sending the slice to migrate to the destination storage unit;

generating a slice verification request and sending the slice verification request to the destination storage unit;

receiving an integrity value from the destination storage unit;

determining when the integrity value compares favorably to the slice verification request, by determining when a hash of the slice and nonce matches the integrity value or determining when a decrypted signature of the integrity value matches a hash of the slice and the nonce or the slice and the nonce;

when the processing system determines that the integrity value compares favorably to the slice verification request, updating a slice name assignment associated with the slice name; and

deleting the slice from the source storage unit.

2. The method of claim 1 wherein identifying the slice name corresponding to the slice to migrate includes at least one of receiving a request, receiving the slice name, receiving an error message, detecting an unfavorable memory condition, performing a lookup, and receiving a memory test result.

3. The method of claim 1 wherein sending the slice to migrate includes sending the slice name to the storage unit.

4. The method of claim 1 wherein the slice verification request includes one or more of:

the slice name, the slice, a revision indicator, a verification method indicator, or the nonce.

5. The method of claim 4 wherein the integrity value includes at least one of:

a hashing function hash result, or a signed package, wherein the package includes the slice and the nonce.

6. The method of claim 1 wherein updating the slice name assignment associates the destination storage unit with the slice name and disassociates the source storage unit with the slice name in a distributed storage and task network (DSTN) address table.

7. The method of claim 1 wherein deleting the slice from the source storage unit includes sending a write slice request to the source storage unit, where the request includes the slice name and an indication to delete the slice.

8. A method for execution by a destination storage unit of a dispersed storage network that includes a processor, the method comprises:

receiving a slice to migrate from a source storage unit;

storing the slice to migrate in a memory device associated with the destination storage unit;

receiving a slice verification request from the source storage unit;

generating an integrity value utilizing the slice to migrate and a nonce of the slice verification request based on a verification method indicator of the request, wherein generating the integrity value includes performing a hashing function on the slice and the nonce to produce a hash result as the integrity value when the verification method indicator indicates to produce a hash result and wherein generating the integrity value includes generating a signature utilizing a private key associated with the destination storage unit over the slice and the nonce to produce a signed package as the integrity value when the verification method indicator indicates to produce a signature; and

sending the integrity value to the source storage unit.

9. The method of claim 8 wherein storing the slice includes storing a slice name associated with the slice in the memory device.

10. The method of claim 8 wherein the slice verification request includes one or more of:

a slice name, the slice, a revision indicator, a verification method indicator, or the nonce.

11. A processing system of a source storage unit of a dispersed storage network comprises:

at least one processor;

a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to;

at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to;

identify a slice name corresponding to a slice to migrate from the source storage unit to a destination storage unit;

send the slice to migrate to the destination storage unit;

generate a slice verification request and send the slice verification request to the destination storage unit;

receive an integrity value from the destination storage unit;

determine when the integrity value compares favorably to the slice verification request, by determining when a hash of the slice and nonce matches the integrity value or determining when a decrypted signature of the integrity value matches a hash of the slice and the nonce or the slice and the nonce;

when the processing system determines that the integrity value compares favorably to the slice verification request, update a slice name assignment associated with the slice name; and

delete the slice from the source storage unit.

12. The processing system of claim 11 wherein identifying the slice name corresponding to the slice to migrate includes at least one of receiving a request, receiving the slice name, receiving an error message, detecting an unfavorable memory condition, performing a lookup, and receiving a memory test result.

13. The processing system of claim 11 wherein the slice verification request includes one or more of:

the slice name, the slice, a revision indicator, a verification method indicator, or the nonce.

14. The processing system of claim 13 wherein the integrity value includes at least one of:

a hashing function hash result, or a signed package, wherein the package includes the slice and the nonce.

15. The processing system of claim 11 wherein updating the slice name assignment associates the destination storage unit with the slice name and disassociates the source storage unit with the slice name in a distributed storage and task network (DSTN) address table.

16. The processing system of claim 11 wherein deleting the slice from the source storage unit includes sending a write slice request to the source storage unit, where the request includes the slice name and an indication to delete the slice.