TARGET PATH SELECTION FOR STORAGE CONTROLLERS

• US 20130311719A1
• Filed: 03/12/2013
• Published: 11/21/2013
• Est. Priority Date: 05/18/2012
• Status: Active Grant

• Current Assignee: ATTO Technology Incorporated
• Original Assignee: ATTO Technology Incorporated
• Inventors: Snell, David A., Doedline, Thomas J. Jr., Rogers, Paul C., Tallau, Stephen W.
• Granted Patent: US 11,474,704 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 2206/1012 Load balancing
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A RAID controller attached to a storage network can detect the presence of multiple pathways to the same physical storage device. A path collection module can dynamically maintain all valid pathways to all attached storage devices. A path selection module can automatically and dynamically balance and rebalance desired paths to each storage device so as to simultaneously optimize data flow and provide continuity of I/O service throughout the attached storage network.

Claims

1. A redundant array of independent disks (RAID) controller associated with a plurality of storage devices attached to said RAID controller, comprising:

an initiator I/O module for receiving data storage commands;

a plurality of target ports for communicating with said plurality of storage devices;

a network discovery module configured to identify said storage devices;

a storage device interface communicating with one or more of said storage devices;

a RAID I/O module directing said data storage commands to said storage device interface;

a path collection module maintaining a set of active target paths available to said storage devices;

a path selection module operable to select desired target paths from one or more of said active target paths, wherein said path selection module is configured to automatically configure the desired target paths to individual storage devices as a function of characteristic parameters of said target paths; and

wherein said RAID controller generates one or more storage device I/O requests to said storage devices using one of the desired target paths determined by said path selection module.

2. The RAID controller of claim 1, wherein said characteristic parameter is the number of available active target paths for each unique storage device.

3. The RAID controller of claim 1, wherein the characteristic parameter is the number of active target paths per target port.

4. The RAID controller of claim 1, wherein the characteristic parameter is the number of active target paths per endpoint network device.

5. A redundant array of independent disks (RAID) controller associated with a plurality of storage devices attached to said RAID controller, comprising:

an initiator I/O module for receiving data storage commands;

a plurality of target ports for communicating with said plurality of storage devices, said plurality of storage devices comprising a RAID group;

a network discovery module configured to identify said storage devices;

a storage device interface communicating with one or more of said storage devices;

a RAID I/O module directing said data storage commands to said storage device interface;

a path collection module maintaining a set of active target paths to said RAID group;

a RAID configuration module for maintaining characteristic parameters of said storage devices that comprise said RAID group;

a path selection module operable to select desired target paths from one or more of said active target paths, wherein said path selection module is configured to automatically configure the desired target path to one of said storage devices in said RAID group based on said characteristic parameters of said storage devices;

wherein said RAID controller generates one or more storage device I/O requests to said storage devices using one of the desired target paths determined by said path selection module.

6. The RAID controller of claim 5, wherein said characteristic parameter is the number of available active target paths for each storage device.

7. The RAID controller of claim 5, wherein said characteristic parameter is the number of active target paths per target port.

8. The RAID controller of claim 5, wherein said characteristic parameter is the number of active paths per endpoint network device.

9. A redundant array of independent disks (RAID) controller associated with a plurality of storage devices attached to said RAID controller, comprising:

an initiator I/O module for receiving data storage commands;

a plurality of target ports for communicating with said plurality of storage devices, said plurality of storage devices comprising a RAID group;

a network discovery module configured to identify said storage devices;

a storage device interface communicating with one or more of said storage devices;

a RAID I/O module directing said data storage commands to said storage device interface;

a path collection module maintaining a set of active target paths to said RAID group;

a RAID configuration module for maintaining characteristic parameters of said storage devices that comprise said RAID group;

a path selection module operable to select desired target paths from one or more of said active target paths, wherein said path selection module is configured to dynamically reconfigure desired target paths to said storage devices as a function of a characteristic triggering event; and

wherein said RAID controller generates one or more storage device I/O requests to said storage devices using one of the desired target paths determined by said path selection module.

10. The RAID controller of claim 9, wherein said characteristic triggering event is a newly created RAID group.

11. The RAID controller of claim 9, wherein said characteristic triggering event is a deleted RAID group.

12. The RAID controller of claim 9, wherein said characteristic triggering event is a RAID group configuration change, wherein the configuration change comprises one of expansion of the RAID group, migration of the RAID group, drive failures within said RAID group, and replacement of an individual storage device of said RAID group.

13. The RAID controller of claim 9, wherein said characteristic triggering event is one of a loss of a previously discovered path and reconnection of a previously discovered path to a storage device of said RAID group.

14. The RAID controller of claim 9, wherein said characteristic triggering event is a newly discovered path to a storage device of said RAID group.

15. A redundant array of independent disks (RAID) controller associated with a plurality of storage devices attached to said RAID controller, comprising:

an initiator I/O module for receiving data storage commands;

a plurality of target ports for communicating with said plurality of storage devices, said plurality of storage devices comprising a collection of one or more RAID groups;

a network discovery module configured to identify said storage devices;

a storage device interface communicating with one or more of said storage devices;

a RAID I/O module directing said data storage commands to said storage device interface;

a path collection module maintaining a set of active target paths to said collection of RAID groups;

a RAID configuration module for maintaining characteristic parameters of said storage devices that comprise said collection of RAID groups;

a path selection module operable to select desired target paths from one or more of said active target paths, wherein said path selection module is configured to automatically configure desired target paths to said storage devices as a function of the collection of RAID groups and associated member paths;

wherein said RAID controller generates one or more storage device I/O requests to said storage devices using one of the desired target paths determined by said path selection module.