Accessing data stored in a dispersed storage memory

• US 8,612,831 B2
• Filed: 06/06/2011
• Issued: 12/17/2013
• Est. Priority Date: 06/22/2010
• Status: Expired due to Fees

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Grube, Gary W., Markison, Timothy W.
• Primary Examiner(s): NGUYEN, STEVE N
• Application Number:
  US13/154,167
• Publication Number:
  US 20110314355A1
• Time in Patent Office: 925 Days
• Field of Search: None
• US Class Current: 714/770
• 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 11/3409 for performance assessment
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• 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

Abstract

A method begins by a processing module forward error correction (FEC) encoding data to produce FEC encoded data and dividing the FEC encoded data into a set of FEC encoded words. The method continues with the processing module generating integrity information based on the data and generating a word name for an FEC encoded word of the set of FEC encoded words. The method continues with the processing module affiliating an address of allocated address space of a dispersed storage memory with the word name and storing the integrity information, the word name, and the address. The method continues with the processing module creating a write command to store the FEC encoded word at the address in the dispersed storage memory.

Claims

1. A method comprises:

forward error correction (FEC) encoding data to produce FEC encoded data;

dividing the FEC encoded data into a set of FEC encoded words;

generating integrity information based on the data;

generating a word name for an FEC encoded word of the set of FEC encoded words;

affiliating an address of allocated address space of a dispersed storage memory with the word name;

storing the integrity information, the word name, and the address; and

creating a write command to store the FEC encoded word at the address in the dispersed storage memory, wherein the dispersed storage memory comprises at least one of;

a local memory of a device executing the method;

a memory of a storage service provider; and

a network coupled memory unit;

determining whether to store the FEC encoded word in the local memory, the memory of the storage service provider, or the network coupled memory unit;

when storing the FEC encoded word in the local memory;

determining available local memory addresses of the allocated address space of the local memory; and

selecting one of the available local memory addresses as the address;

when storing the FEC encoded word in the memory of the storage service provider;

determining available service provider memory addresses of the allocated address space of the memory of the storage service provider; and

selecting one of the available service provider memory addresses as the address; and

when storing the FEC encoded word in the network coupled memory unit;

determining available network memory addresses of the allocated address space of the network coupled memory unit; and

selecting one of the available network memory addresses as the address.

2. The method of claim 1, wherein the generating the integrity information comprises at least one of:

performing a hash algorithm on the data to produce the integrity information;

performing a hash-based message authentication code (HMAC) on the data to produce the integrity information;

performing a parity function on the data to produce the integrity information;

performing a cyclic redundancy check function on the data to produce the integrity information; and

performing a mask generating function (MGT) on the data to produce the integrity information.

3. The method of claim 1 further comprises:

generating a second word name for a second FEC encoded word of the set of FEC encoded words;

affiliating a second address of allocated address space of the dispersed storage memory with the second word name;

storing the second word name with the integrity information, the word name, and the address; and

creating a second write command to store the second FEC encoded word at the second address in the dispersed storage memory.

4. A computer comprises:

an interface;

a memory; and

a processing module operable to;

forward error correction (FEC) encode data to produce FEC encoded data;

divide the FEC encoded data into a set of FEC encoded words;

generate integrity information based on the data;

generate a word name for an FEC encoded word of the set of FEC encoded words;

affiliate an address of allocated address space of a dispersed storage memory with the word name;

store, via the interface, the integrity information, the word name, and the address; and

create a write command to store, via the interface, the FEC encoded word at the address in the dispersed storage memory, wherein the dispersed storage memory comprises at least one of;

a local memory of a device executing the method;

a memory of a storage service provider; and

a network coupled memory unit;

determine whether to store the FEC encoded word in the local memory, the memory of the storage service provider, or the network coupled memory unit;

when storing the FEC encoded word in the local memory;

determine available local memory addresses of the allocated address space of the local memory; and

select one of the available local memory addresses as the address;

when storing the FEC encoded word in the memory of the storage service provider;

determine available service provider memory addresses of the allocated address space of the memory of the storage service provider; and

select one of the available service provider memory addresses as the address; and

when storing the FEC encoded word in the network coupled memory unit;

determine available network memory addresses of the allocated address space of the network coupled memory unit; and

select one of the available network memory addresses as the address.

5. The computer of claim 4, wherein the processing module functions to generate the integrity information by at least one of:

performing a hash algorithm on the data to produce the integrity information;

performing a hash-based message authentication code (HMAC) on the data to produce the integrity information;

performing a parity function on the data to produce the integrity information;

performing a cyclic redundancy check function on the data to produce the integrity information; and

performing a mask generating function (MGT) on the data to produce the integrity information.

6. The computer of claim 4, wherein the processing module further functions to:

generate a second word name for a second FEC encoded word of the set of FEC encoded words;

affiliate a second address of allocated address space of the dispersed storage memory with the second word name;

store, via interface, the second word name with the integrity information, the word name, and the address; and

create a second write command to store, via the interface, the second FEC encoded word at the second address in the dispersed storage memory.