Detecting storage errors in a dispersed storage network

Patent metadata

Field	Value
Publication number	US-2018107553-A1
Application number	US-201715846728-A
Country	US
Kind code	A1
Filing date	Dec 19, 2017
Priority date	Mar 31, 2015
Publication date	Apr 19, 2018
Grant date	—

Abstract

A method for execution by a computing device includes updating a storage error list in response to detecting a write slice failure. The storage error list is also updated in response to detecting a failure of a storage unit memory, wherein the storage unit memory is utilized to store a first at least one of a plurality of encoded data slices. A first range error message is issued in response to detecting loss of a local slice name list associated with storage of a second at least one of the plurality of encoded data slices. The storage error list is updated in response to receiving a second range error message. Rebuilding of a third at least one of the plurality of encoded data slices is facilitated based on interpreting the storage error list.

First claim

What is claimed is:

1 . A method for execution by a computing device that includes a processor, the method comprises:
updating a storage error list in response to detecting a write slice failure; updating the storage error list in response to detecting a failure of a storage unit memory, wherein the storage unit memory is utilized to store a first at least one of a plurality of encoded data slices; issuing a first range error message in response to detecting loss of a local slice name list associated with storage of a second at least one of the plurality of encoded data slices; updating the storage error list in response to receiving a second range error message; and facilitating rebuilding of a third at least one of the plurality of encoded data slices based on interpreting the storage error list.

2 . The method of claim 1 , wherein updating the storage error list in response to detecting the write slice failure includes:
identifying a slice name associated with write slice rhetoric of the write slice failure; generating a modified storage error list to include the slice name; and publishing the modified storage error list to at least one other entity of a dispersed storage network (DSN).

3 . The method of claim 1 , wherein updating the storage error list in response to detecting the failure of the storage unit memory includes:
identifying a plurality of slice names from the local slice name list; generating a modified storage error list to include the plurality of slice names; and publishing the modified storage error list to at least one other entity of a dispersed storage network (DSN).

4 . The method of claim 1 , wherein issuing the first range error message includes:
identifying a DSN address range associated with the local slice name list; generating the first range error message to include the identified DSN address range; selecting one storage unit from a plurality of storage units; and sending the first range error message to the one storage unit.

5 . The method of claim 1 , wherein updating the storage error list in response to receiving the second range error message includes:
extracting a DSN address range from the second range error message; identifying a plurality of locally stored encoded data slices associated with a local DSN address range that corresponds to the DSN address range; identifying a plurality of identified slice names of the plurality of locally stored encoded data slices; generating a plurality of generated slice names for the DSN address range based on the plurality of identified slice names; generating a modified storage error list to include the plurality of generated slice names; and publishing the modified storage error list.

6 . The method of claim 1 , wherein facilitating rebuilding of the third at least one of the plurality of encoded data slices includes:
extracting a slice name of the third at least one of the plurality of encoded data slices from the storage error list; obtaining a decode threshold number of encoded data slices of a data segment associated with the slice name; dispersed storage error decoding the decode threshold number of encoded data slices to generate a reproduced data segment; dispersed storage error encoding the reproduced data segment to produce a rebuilt encoded data slice associated with the slice name; and facilitating storage of the rebuilt encoded data slice in a memory of a storage unit associated with the slice name.

7 . The method of claim 6 , wherein obtaining the decode threshold number of encoded data slices includes:
generating a decode threshold number of other slice names associated with the data segment; issuing a plurality of read slice requests that includes the decode threshold number of other slice names to a plurality of storage units; and receiving a plurality of read slice responses that includes the decode threshold number of encoded data slices.

8 . A processing system of a computing device 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:
update a storage error list in response to detecting a write slice failure;
update the storage error list in response to detecting a failure of a storage unit memory, wherein the storage unit memory is utilized to store a first at least one of a plurality of encoded data slices;
issue a first range error message in response to detecting loss of a local slice name list associated with storage of a second at least one of the plurality of encoded data slices;
update the storage error list in response to receiving a second range error message; and
facilitate rebuilding of a third at least one of the plurality of encoded data slices based on interpreting the storage error list.

9 . The processing system of claim 8 , wherein updating the storage error list in response to detecting the write slice failure includes:
identifying a slice name associated with write slice rhetoric of the write slice failure; generating a modified storage error list to include the slice name; and publishing the modified storage error list to at least one other entity of a dispersed storage network (DSN).

10 . The processing system of claim 8 , wherein updating the storage error list in response to detecting the failure of the storage unit memory includes:
identifying a plurality of slice names from the local slice name list; generating a modified storage error list to include the plurality of slice names; and publishing the modified storage error list to at least one other entity of a dispersed storage network (DSN).

11 . The processing system of claim 8 , wherein issuing the first range error message includes:
identifying a DSN address range associated with the local slice name list; generating the first range error message to include the identified DSN address range; selecting one storage unit from a plurality of storage units; and sending the first range error message to the one storage unit.

12 . The processing system of claim 8 , wherein updating the storage error list in response to receiving the second range error message includes:
extracting a DSN address range from the second range error message; identifying a plurality of locally stored encoded data slices associated with a local DSN address range that corresponds to the DSN address range; identifying a plurality of identified slice names of the plurality of locally stored encoded data slices; generating a plurality of generated slice names for the DSN address range based on the plurality of identified slice names; generating a modified storage error list to include the plurality of generated slice names; and publishing the modified storage error list.

13 . The processing system of claim 8 , wherein facilitating rebuilding of the third at least one of the plurality of encoded data slices includes:
extracting a slice name of the third at least one of the plurality of encoded data slices from the storage error list; obtaining a decode threshold number of encoded data slices of a data segment associated with the slice name; dispersed storage error decoding the decode threshold number of encoded data slices to generate a reproduced data segment; dispersed storage error encoding the reproduced data segment to produce a rebuilt encoded data slice associated with the slice name; and facilitating storage of the rebuilt encoded data slice in a memory of a storage unit associated with the slice name.

14 . The processing system of claim 13 , wherein obtaining t

Assignees

• IBM

Inventors

• Leggette Wesley B
• Resch Jason K

Classifications

• H03M13/1515

  Reed-Solomon codes · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F11/1092 Primary

  Rebuilding, e.g. when physically replacing a failing disk · CPC title

• H03M13/154

  Error and erasure correction, e.g. by using the error and erasure locator or Forney polynomial · CPC title

• G06F3/064

  Management of blocks · CPC title