Recovery mechanisms across storage nodes that reduce the impact on host input and output operations

Patent metadata

Field	Value
Publication number	US-10664341-B2
Application number	US-201816053538-A
Country	US
Kind code	B2
Filing date	Aug 2, 2018
Priority date	May 28, 2014
Publication date	May 26, 2020
Grant date	May 26, 2020

Abstract

Provided are a method, a system, and a computer program product in which a storage controller determines one or more resources that are impacted by an error. A cleanup of tasks associated with the one or more resources that are impacted by the error is performed, to recover from the error, wherein host input/output (I/O) operations continue to be processed, and wherein tasks associated with other resources continue to execute.

First claim

What is claimed is:

1. A method, comprising:
in response to determining that a resource is impacted by an error in an I/O path, determining whether the impacted resource is currently executing I/O; and
in response to determining that the impacted resource is currently not executing I/O, determining whether operations are being performed in a non I/O recovery sequence for the impacted resource.

2. The method of claim 1 , the method further comprising:
performing a cleanup of tasks associated with the resource that is impacted by the error, to recover from the error.

3. The method of claim 2 , wherein:
no communication is made to tasks associated with other resources to indicate that the cleanup is being performed; and
no communication is made to a host that has initiated host I/O operations to indicate that the cleanup is being performed.

4. The method of claim 2 , wherein:
the cleanup of the tasks associated with the resource that is impacted by the error is performed asynchronously.

5. The method of claim 1 the method further comprising:
in response to determining that operations are not being performed in the non I/O recovery sequence for the impacted resource, starting another non I/O recovery sequence;
in response to determining that operations are being performed in the non I/O recovery sequence for the impacted resource, determining whether the non I/O recovery sequence has reached a point where a new task has been started for the impacted resource; and
in response to determining that the new task has not been started for the impacted resource, continuing with execution of the non I/O recover sequence.

6. The method of claim 5 , the method further comprising:
in response to determining that the new task has been started for the impacted resource, starting the another non I/O recovery sequence.

7. A system, comprising:
a memory; and
a processor coupled to the memory, wherein the processor performs operations, the operations comprising:
in response to determining that a resource is impacted by an error in an I/O path, determining whether the impacted resource is currently executing I/O; and
in response to determining that the impacted resource is currently not executing I/O, determining whether operations are being performed in a non I/O recovery sequence for the impacted resource.

8. The system of claim 7 , the operations further comprising:
performing a cleanup of tasks associated with the resource that is impacted by the error, to recover from the error.

9. The system of claim 8 , wherein:
no communication is made to tasks associated with other resources to indicate that the cleanup is being performed; and
no communication is made to a host that has initiated host I/O operations to indicate that the cleanup is being performed.

10. The system of claim 8 , wherein:
the cleanup of the tasks associated with the resource that is impacted by the error is performed asynchronously.

11. The system of claim 7 the operations further comprising:
in response to determining that operations are not being performed in the non I/O recovery sequence for the impacted resource, starting another non I/O recovery sequence;
in response to determining that operations are being performed in the non I/O recovery sequence for the impacted resource, determining whether the non I/O recovery sequence has reached a point where a new task has been started for the impacted resource; and
in response to determining that the new task has not been started for the impacted resource, continuing with execution of the non I/O recover sequence.

12. The system of claim 11 , the operations further comprising:
in response to determining that the new task has been started for the impacted resource, starting the another non I/O recovery sequence.

13. A computer program product, the computer program product comprising:
a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to perform operations on a storage controller, the operations comprising:
in response to determining that a resource is impacted by an error in an I/O path, determining whether the impacted resource is currently executing I/O; and
in response to determining that the impacted resource is currently not executing I/O, determining whether operations are being performed in a non I/O recovery sequence for the impacted resource.

14. The computer program product of claim 13 , the operations further comprising:
performing a cleanup of tasks associated with the resource that is impacted by the error, to recover from the error.

15. The computer program product of claim 14 , wherein:
no communication is made to tasks associated with other resources to indicate that the cleanup is being performed; and
no communication is made to a host that has initiated host I/O operations to indicate that the cleanup is being performed.

16. The computer program product of claim 14 , wherein:
the cleanup of the tasks associated with the resource that is impacted by the error is performed asynchronously.

17. The computer program product of claim 13 , the operations further comprising:
in response to determining that operations are not being performed in the non I/O recovery sequence for the impacted resource, starting another non I/O recovery sequence;
in response to determining that operations are being performed in the non I/O recovery sequence for the impacted resource, determining whether the non I/O recovery sequence has reached a point where a new task has been started for the impacted resource; and
in response to determining that the new task has not been started for the impacted resource, continuing with execution of the non I/O recover sequence.

18. The computer program product of claim 17 , the operations further comprising:
in response to determining that the new task has been started for the impacted resource, starting the another non I/O recovery sequence.

Assignees

• IBM

Inventors

• He Wang Ping
• Juarez Larry
• Kalos Matthew J
• Mccauley John N
• Rasor Louis A
• Rinaldi Brian A
• Sorenson Todd C

Classifications

• G06F11/0727

  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 title

• G06F11/0745

  in an input/output transactions management context (input/output processing in general G06F13/00) · CPC title

• G06F11/0793 Primary

  Remedial or corrective actions (recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40) · CPC title

• G06F11/2017

  where memory access, memory control or I/O control functionality is redundant (redundant communication control functionality G06F11/2005; redundant storage control functionality G06F11/2089) · CPC title

• G06F11/2094

  Redundant storage or storage space (G06F11/2056 takes precedence) · CPC title