SYSTEM AND PROGRAM FOR ERROR HANDLING IN A DUAL ADAPTOR SYSTEM WHERE ONE ADAPTOR IS A MASTER

• US 20090119539A1
• Filed: 01/08/2009
• Published: 05/07/2009
• Est. Priority Date: 11/29/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jones, Michael John, Vageline, Michael P., Fairhurst, Matthew John, Legvold, Vernon J.
• Granted Patent: US 7,774,644 B2
• Time in Patent Office: Days
• US Class Current: 714/9
• CPC Class Codes: G06F 11/0727 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 Class Codes: G06F 11/0745 in an input/output transactions management context input/output processing in general G06F13/00
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/0793 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 Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: H04L 12/42 Loop networks

Abstract

Provided is a method, system, and program for processing Input/Output (I/O) requests to a storage network including at least one storage device and at least two adaptors, wherein each adaptor is capable of communicating I/O requests to the at least one storage device. An error is detected in a system including a first adaptor, wherein the first adaptor is capable of communicating on the network after the error is detected. In response to detecting the error, a master switch timer is started that is less than a system timeout period if the first adaptor is the master. An error recovery procedure in the system including the first adaptor would be initiated after the system timeout period has expired. An operation is initiated to designate another adaptor in the storage network as the master if the first adaptor is the master in response to detecting an expiration of the master switch timer.

Claims

1. A system for processing Input/Output (I/O) requests to a storage network including at least one storage device and a system including a first adaptor capable of communicating I/O requests to at least one storage device, wherein the system including the first adaptor initiates an error recovery procedure after a system timeout period has expired, comprising:

a second adaptor capable of communicating on the storage network;

means for detecting an error in the system including the first adaptor, wherein the first adaptor is capable of communicating on the storage network after the error is detected;

means for determining whether the first adaptor is designated a master of the storage network after the error is detected;

means for starting a master switch timer, after detecting the error, that is less than the system timeout period if the first adaptor is the master; and

means for initiating an operation to designate the second adaptor in the storage network as the master if the first adaptor is the master in response to detecting an expiration of the master switch timer, wherein a reset request is sent to an identifier of the first adapter after the master switch timer expires.

2. The system of claim 1, wherein the first adapter is in a first computer system and wherein the second adapter is in a second computer system.

3. A computer readable medium including code for processing Input/Output (I/O) requests to a storage network including at least one storage device and at least two adaptors, wherein each adaptor is capable of communicating I/O requests to at least one storage device, wherein the code when executed by a processor causes operations, the operations comprising:

detecting an error in a system including a first adaptor, wherein the first adaptor is capable of communicating on the storage network after the error is detected;

determining whether the first adaptor is designated a master of the storage network after the error is detected;

starting a master switch timer that is less than a system timeout period if the first adaptor is the master after detecting the error, wherein an error recovery procedure in the system including the first adaptor is initiated after the system timeout period has expired; and

initiating an operation to designate a second adaptor in the storage network as the master if the first adaptor is the master in response to detecting an expiration of the master switch timer, wherein a reset request is sent to an identifier of the first adapter after the master switch timer expires.

4. The computer readable medium of claim 3, wherein the first adapter is in a first computer system and wherein the second adapter is in a second computer system.