Managing software errors in storage systems

Patent metadata

Field	Value
Publication number	US-9367405-B1
Application number	US-201313804506-A
Country	US
Kind code	B1
Filing date	Mar 14, 2013
Priority date	Mar 14, 2013
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A method is used in managing software errors in storage systems. It is detected that a first processor of a storage system has a problem performing an I/O on a logical object. The first processor has a first path to the logical object. The problem includes a software error. Whether responsibility of performing the I/O on the logical object is transferred to a second processor of the storage system is evaluated. The second processor has a second path to the logical object.

First claim

What is claimed is:

1. A method for use in managing software errors in storage systems, the method comprising:
detecting that a first processor of a storage system has a problem performing an I/O on a logical object, wherein the first processor has a first path to the logical object, wherein the problem includes a software error, wherein the storage system includes first and second processors, wherein the first processor has a primary responsibility for performing the I/O on the logical object;
evaluating whether to transfer responsibility of performing the I/O on the logical object to the second processor of the storage system, wherein the second processor has a second path to the logical object, wherein evaluating whether to transfer responsibility of performing the I/O includes determining whether subsequently performing the I/O on the logical object by the first processor resolves the software error and based on the determination, determining whether the second processor is available for performing the I/O operation on the logical object;
based on the determination that the software error has not been resolved and the second processor is available for performing the I/O on the logical object, transferring responsibility of performing the I/O on the logical object to the second processor of the storage system upon receiving an indication from the second processor that the first processor can fail, wherein responsibility of performing the I/O on the logical object is transferred to the second processor upon failure of the first processor, wherein the failure of the first processor includes reboot of the first processor; and
based on the determination that the software error has not been resolved and the second processor is not available for performing the I/O on the logical object, making the logical object inaccessible to a user of the logical object without having to reboot the storage system.

2. The method of claim 1 , further comprising:
based on the evaluation, determining whether to fail the logical object by making the logical object inaccessible.

3. The method of claim 1 , further comprising:
retrying the I/O on the logical object upon detecting the problem.

4. The method of claim 3 , further comprising:
based on the result of retrying the I/O, determining whether to fail the first processor of the storage system.

5. The method of claim 1 , wherein the logical object comprises a set of LUNs on disk drives in a RAID group.

6. The method of claim 1 , wherein the logical object is represented by a first object on the first processor of the storage system and by a second object on the second processor of the storage system.

7. The method of claim 6 , wherein the first object communicates with the second object to determine whether the first processor can panic.

8. The method of claim 1 , further comprising:
providing a status of the problem to the logical object.

9. The method of claim 2 , further comprising:
making the logical object accessible upon successful reboot of the first and second processors of the storage system.

10. The method of claim 1 , wherein the logical object is in communication with a RAID object and the RAID object is in communication with a physical object.

11. A system for use in managing software errors in storage systems, the system comprising:
first logic detecting that a first processor of a storage system has a problem performing an I/O on a logical object, wherein the first processor has a first path to the logical object, wherein the problem includes a software error, wherein the storage system includes first and second processors, wherein the first processor has a primary responsibility for performing the I/O on the logical object;
second logic evaluating whether to transfer responsibility of performing the I/O on the logical object to the second processor of the storage system, wherein the second processor has a second path to the logical object, wherein evaluating whether to transfer responsibility of performing the I/O includes determining whether subsequently performing the I/O on the logical object by the first processor resolves the software error and based on the determination, determining whether the second processor is available for performing the I/O operation on the logical object;
third logic transferring responsibility, based on the determination that the software error has not been resolved and the second processor is available for performing the I/O on the logical object, of performing the I/O on the logical object to the second processor of the storage system upon receiving an indication from the second processor that the first processor can fail, wherein responsibility of performing the I/O on the logical object is transferred to the second processor upon failure of the first processor, wherein the failure of the first processor includes reboot of the first processor; and
fourth logic making, based on the determination that the software error has not been resolved and the second processor is not available for performing the I/O on the logical object, making the logical object inaccessible to a user of the logical object without having to reboot the storage system.

12. The system of claim 11 , further comprising:
fifth logic determining, based on the evaluation, whether to fail the logical object by making the logical object inaccessible.

13. The system of claim 11 , further comprising:
fifth logic retrying the I/O on the logical object upon detecting the problem.

14. The system of claim 13 , further comprising:
sixth logic determining, based on the result of retrying the I/O, whether to fail the first processor of the storage system.

15. The system of claim 11 , wherein the logical object comprises a set of LUNs on disk drives in a RAID group.

16. The system of claim 11 , wherein the logical object is represented by a first object on the first processor of the storage system and by a second object on the second processor of the storage system.

17. The system of claim 16 , wherein the first object communicates with the second object to determine whether the first processor can panic.

18. The system of claim 11 , further comprising:
fifth logic providing a status of the problem to the logical object.

19. The system of claim 12 , further comprising:
sixth logic making the logical object accessible upon successful reboot of the first and second processors of the storage system.

20. The system of claim 11 , wherein the logical object is in communication with a RAID object and the RAID object is in communication with a physical object.

Assignees

• Emc Corp

Inventors

• Foley Robert P
• Puhov Peter
• Cassano Marc C
• Cummins Daniel E
• Harvey David W

Classifications

• G06F11/1474 Primary

  in transactions (updating of structured data in databases G06F16/23) · CPC title

• G06F11/142 Primary

  Reconfiguring to eliminate the error (group management mechanisms in a peer-to-peer network H04L67/1044) · CPC title

• G06F11/07 Primary

  Responding to the occurrence of a fault, e.g. fault tolerance · CPC title

• G06F11/1415

  at system level · CPC title

• G06F11/2092

  Techniques of failing over between control units · CPC title