COMPUTER SYSTEM AND METHOD FOR PERFORMING FAILURE DETECTING PROCESSING FOR A LOGICAL PATH

• US 20100050022A1
• Filed: 11/03/2009
• Published: 02/25/2010
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Makoto Aoki, Yuki Komatsu
• Original Assignee: Makoto Aoki, Yuki Komatsu
• Inventors: Aoki, Makoto, KOMATSU, Yuki
• Granted Patent: US 7,992,048 B2
• Time in Patent Office: Days
• US Class Current: 714/43
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Provided is a computer system including at least one host computer; and at least one storage system, characterized in that: the storage system has a disk drive and a disk controller, and provides a storage area of the disk drive as at least one logical unit; upon detecting a failure in a logical path serving as an access route from the host computer to the logical unit, the host computer specifies logical paths for accessing the same logical unit that is connected to the logical path where the failure is detected; the host computer executes failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not; the host computer selects normal logical paths out of the specified logical paths; and the host computer accesses the logical unit via the normal logical paths selected.

Claims

1. A computer system, comprising:

at least one first host computer having a processor, a memory, and an interface; and

at least one storage system connected to the first host computer,

wherein the storage system has a disk drive for storing data that is requested to be written by the first host computer and a disk controller for controlling the disk drive, and provides a storage area of the disk drive as at least one logical unit to the first host computer,

wherein upon detecting a failure in a logical path serving as an access route from the first host computer to the logical unit, the first host computer specifies logical paths for accessing the logical unit,

wherein the first host computer executes failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not,

wherein the first host computer selects normal logical paths out of the specified logical paths,

wherein the first host computer accesses the logical unit via the selected normal logical paths,

wherein the first host computer stores logical path connection information, which indicates association between the logical path and components passed by the logical path,

wherein the first host computer blocks the logical path where a failure is detected and a logical path that is judged as abnormal through the failure detecting processing,

wherein the first host computer estimates, as a cause of the failure, a component passed by only the blocked logical paths by referring to the logical path connection information,

the computer system further comprising a management server connected to the first host computer,

wherein the first host computer notifies the management server of the estimated cause of the failure,

wherein the management server notifies the estimated cause of the failure, which is notified by the first host computer, to a second host computer, which is not the first host computer,

wherein the second host computer specifies the logical paths that pass the notified cause of the failure,

wherein the second host computer executes failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not,

wherein the disk controller has at least one channel adapter connected to the first host computer,

wherein the first host computer has at least one host bus adapter connected to the storage system, and

wherein the first host computer estimates the host bus adapter, the channel adapter, or the logical unit as a cause of a failure.

2. A logical path switching method for a computer system that includes at least one first host computer having a processor, a memory, and an interface, at least one storage system connected to the first host computer, and a management server connected to the first host computer,

wherein the storage system has a disk drive for storing data that is requested to be written by the first host computer and a disk controller for controlling the disk drive, the logical path switching method comprising the steps of:

providing, by the storage system, a storage area of the disk drive to the first host computer;

upon detecting a failure in a logical path serving as an access route from the first host computer to the logical unit, specifying, by the first host computer, logical paths for accessing the logical unit;

executing, by the first host computer, failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not;

selecting, by the first host computer, normal logical paths out of the specified logical paths;

accessing, by the first host computer, the logical unit via the selected normal logical paths;

storing, by the first host computer, logical path connection information, which indicates association between the logical path and components passed by the logical path;

blocking, by the first host computer, the logical path where a failure is detected and a logical path that is judged as abnormal through the failure detecting processing,

estimating, by the first host computer, as a cause of the failure, a component passed by only the blocked logical paths by referring to the logical path connection information,

notifying, by the first host computer, the management server of the estimated cause of the failure,

notifying, by the management server, the estimated cause of the failure, which is notified by the first host computer, to a second host computer, which is not the first host computer;

specifying, by the second host computer, the logical paths that pass the notified cause of the failure;

executing, by the second host computer, failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not, and

in the failure detecting processing, further executing by the first host computer, failure detecting processing also for the logical path for accessing the logical unit that is different from the logical unit accessed by the logical path where the failure is detected.

3. A logical path switching method for a computer system that includes:

a plurality of host computers, each containing a processor, a memory, and an interface, at least one storage system connected to the host computers, and a management server containing a processor, a memory, and an interface and connected to the host computers,

wherein the storage system has a disk drive for storing data that is requested to be written by the host computers and a disk controller for controlling the disk drive,

wherein the host computers include a first host computer and a second host computer, and

wherein the logical path switching method comprises the steps of;

providing, by the storage system, a storage area of the disk drive as one or more logical units to the first host computer and the second host computer;

storing, by the first host computer, logical path connection information indicating association between a logical path serving as an access route from the first host computer to the logical unit and components passed by the logical path;

identifying, by the first host computer, which ones of all logical paths are currently blocked;

executing, by the first host computer, failure detecting processing for the logical paths identified as blocked paths to judge whether the logical paths identified as blocked paths are normal or not;

selecting, by the first host computer, normal logical paths out of the logical paths identified as blocked paths;

referring, by the first host computer, to the logical path connection information to estimate, as a component that has recovered from a failure, one of failure recovery components passed by the selected normal logical paths;

notifying, by the first host computer, the management server of the estimated failure recovery component; and

notifying, by the management server, the notified failure recovery component to the second host computers.