Multiple memory format storage in a storage network

• US 10,146,645 B2
• Filed: 08/16/2016
• Issued: 12/04/2018
• Est. Priority Date: 11/01/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Dhuse, Greg R., Grube, Gary W., Resch, Jason K.
• Primary Examiner(s): Shanmugasundaram, Kannan
• Application Number:
  US15/238,031
• Publication Number:
  US 20160357646A1
• Time in Patent Office: 840 Days
• CPC Class Codes: G06F 11/00 Error detection; Error correction; Monitoring error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1474 in transactions G06F16/20 takes precedence
• CPC Class Codes: G06F 11/1612 where the redundant component is persistent storage
• CPC Class Codes: G06F 11/167 Error detection by comparing the memory output
• CPC Class Codes: G06F 2201/805 Real-time
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency
• CPC Class Codes: G06F 2201/85 Active fault masking without idle spares
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• 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 includes sending a data retrieval request regarding a data segment of a data object to redundant array of independent disk (RAID) memory and to dispersed storage network (DSN) memory. The method further includes receiving a first read response from a first one of the RAID memory and the DSN memory. The method further comprises recovering the data segment from the first read response. The method further includes determining whether to wait for a second read response from a second one of the RAID memory and the DSN memory. When the computing device determines to wait, the method further includes receiving the second response within a given time frame. The method further includes recovering a copy of the data segment from the second read response. When the data segment substantially matches the copy of the data segment, the method further includes utilizing either the data segment or the copy of the data segment.

Claims

1. A method comprises:

sending, by a computing device of a storage network, a data retrieval request regarding a data segment of a data object to redundant array of independent disk (RAID) memory of the storage network and to dispersed storage network (DSN) memory of the storage network;

receiving, by the computing device, a first read response from a first one of the RAID memory and the DSN memory;

recovering, by the computing device, the data segment from the first read response;

waiting, by the computing device, for a given time frame, for a second read response from a second one of the RAID memory and the DSN memory;

when the second read response is received within the given timeframe;

recovering, by the computing device, a copy of the data segment from the second read response;

comparing, by the computing device, the data segment and the copy of the data segment; and

when the data segment substantially matches the copy of the data segment, utilizing, by the computing device, either the data segment or the copy of the data segment; and

when the data segment does not substantially match the copy of the data segment, indicating, by the computing device, a read error.

2. The method of claim 1, wherein the recovering the data segment from the first read response further comprises:

when the first read response is from the DSN memory;

receiving, by the computing device, a decode threshold number of encoded data slices,

wherein the data segment was dispersed storage error encoded into a set of encoded data slices; and

dispersed storage error decoding the decode threshold number of encoded data slices to recover the data segment.

3. The method of claim 1, wherein the recovering the data segment from the first read response further comprises:

when the first read response is from the RAID memory;

retrieving, by the computing device, a data stripe from the RAID memory; and

recovering, by the computing device, the data segment from the data stripe.

4. The method of claim 1 further comprises:

when the second read response is not received within the given time frame, determining, by the computing device, whether the second one of the RAID memory and the DSN memory is available; and

when the second one of the RAID memory and the DSN memory is not available, utilizing, by the computing device, the data segment.

5. The method of claim 4 further comprises:

when the second one of the RAID memory and the DSN memory is not available because the second one of the RAID memory and the DSN memory is not currently storing an encoded representation of the data segment;

determining, by the computing device, whether to further store the data segment in the second one of the RAID memory and the DSN memory; and

encoding, by the computing device, the data segment for storage in the second one of the RAID memory and the DSN memory.

6. A computing device comprises:

an interface;

memory; and

a processing module operably coupled to the interface and the memory, wherein the processing module is operably coupled to;

send, via the interface, a data retrieval request regarding a data segment of a data object to redundant array of independent disk (RAID) memory of a storage network and to dispersed storage network (DSN) memory of the storage network;

receive, via the interface, a first read response from a first one of the RAID memory and the DSN memory;

recover the data segment from the first read response;

wait for a given time frame, for a second read response from a second one of the RAID memory and the DSN memory;

when the second read response is received via the interface, within the given time frame;

recover a copy of the data segment from the second read response;

compare the data segment and the copy of the data segment; and

when the data segment substantially matches the copy of the data segment, utilize either the data segment or the copy of the data segment; and

when the data segment does not substantially match the copy of the data segment, indicate a read error.

7. The computing device of claim 6, wherein the processing module is further operable to recover the data segment from the first read response by:

when the first read response is from the DSN memory;

receiving, via the interface, a decode threshold number of encoded data slices, wherein the data segment was dispersed storage error encoded into a set of encoded data slices; and

dispersed storage error decode the decode threshold number of encoded data slices to recover the data segment.

8. The computing device of claim 6, wherein the processing module is further operable to recover the data segment from the first read response by:

when the first read response is from the RAID memory;

retrieving a data stripe from the RAID memory; and

recovering the data segment from the data stripe.

9. The computing device of claim 6, wherein the processing module is further operable to:

when the second read response is not received within the given time frame, determine whether the second one of the RAID memory and the DSN memory is available; and

when the second one of the RAID memory and the DSN memory is not available, utilize the data segment.

10. The computing device of claim 9, wherein the processing module is further operable to

when the second one of the RAID memory and the DSN memory is not available because the second one of the RAID memory and the DSN memory is not currently storing an encoded representation of the data segment:

determine whether to further store the data segment in the second one of the RAID memory and the DSN memory; and

encode the data segment for storage in the second one of the RAID memory and the DSN memory.