Storage system with capability to allocate virtual storage segments among a plurality of controllers

• US 20050172097A1
• Filed: 01/30/2004
• Published: 08/04/2005
• Est. Priority Date: 01/30/2004
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Voigt, Doug, Woods, Hal
• Granted Patent: US 7,305,520 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 11/3485 for I/O devices
• 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 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A storage system comprises a plurality of storage arrays configurable into a plurality of storage device groups, a plurality of controllers selectively coupled to ones of the storage arrays, a network fabric arranged as a linkage of multiple sets of associated controllers and storage devices, and a processor. The processor is capable of associating the plurality of storage device groups among controllers based on a distribution of performance demand according to controller processor utilization of the individual storage device groups and bandwidth utilization pro-ratable among storage device groups within a set.

Claims

1. A method of allocating control of virtual storage segments in a storage system among a plurality of controllers, the storage system being arranged as multiple sets of associated controllers and storage devices, the method comprising:

determining performance demand among a plurality of storage device groups;

distributing performance demand values according to controller processor utilization of the individual storage device groups and bandwidth utilization pro-ratable among storage device groups within a set; and

associating the plurality of storage device groups with controllers based on the performance demand value distributions.

2. The method according to claim 1 further comprising:

measuring performance demand including measurements of data transfer bandwidth and/or operations executed per second.

3. The method according to claim 1 further comprising:

estimating performance demand including enumerating performance demand as a proportion of per-storage device throughput and/or evaluating implemented upstream workload throttling parameters.

4. The method according to claim 1 further comprising:

establishing utilization guidelines for controller processor and inter-set communication.

5. The method according to claim 1 further comprising:

establishing utilization guidelines for controller processor and inter-set communication including guidelines for maximum utilization targets and/or appropriateness of equalization across controller processors.

6. The method according to claim 1 further comprising:

optimizing the allocation of controllers and storage device groups using three-dimensional bin-packing techniques with the dimensions defined as virtual slots, controller processor utilization, and inter-set link utilization.

7. The method according to claim 1 further comprising:

optimizing the allocation of controllers and storage device groups using a custom heuristic algorithm.

8. The method according to claim 1 further comprising:

optimizing the allocation of controllers and storage device groups using selection from among a set of pre-planned controller to storage device group association patterns.

9. The method according to claim 1 further comprising:

determining whether a storage device group to controller allocation meets preselected criteria;

if so, allocating the storage devices groups and controllers; and

if not, indicating allocation failure and responding with one or more actions selected from among a group of actions including adding controllers, adding inter-set bandwidth, adding storage devices, and reconfiguring storage device groupings by moving data.

10. The method according to claim 1 further comprising:

optimizing the allocation of controllers and storage device groups;

determining whether the optimized allocation of storage device groups to controllers improves performance;

if so, allocating the storage devices groups and controllers; and

if not, indicating failure to improve allocation and responding with no action or one or more actions selected from among a group actions including adding controllers, adding inter-set bandwidth, adding storage devices, and reconfiguring storage device groupings by moving data.

11. The method according to claim 1 further comprising:

optimizing the allocation of controllers and storage device groups; and

planning a sequence of virtual storage segment movements that advance from a current state to the optimized state.

12. A storage system comprising:

a plurality of storage arrays configurable into a plurality of storage device groups;

a plurality of controllers selectively coupled to ones of the storage arrays;

a network fabric arranged as a linkage of multiple sets of associated controllers and storage devices; and

a processor capable of associating the plurality of storage device groups among controllers based on a distribution of performance demand according to controller processor utilization of the individual storage device groups and bandwidth utilization pro-ratable among storage device groups within a set.

13. A storage system according to claim 12 further comprising:

a process executable in the processor that determines performance demand among a plurality of storage device groups by measuring performance demand including measurements of data transfer bandwidth and/or operations executed per second.

14. A storage system according to claim 12 further comprising:

a process executable in the processor that determines performance demand among a plurality of storage device groups by estimating performance demand including enumerating performance demand as a proportion of per-storage device throughput and/or evaluating implemented upstream workload throttling parameters.

15. A storage system according to claim 12 further comprising:

a process executable in the processor that optimizes the allocation of controllers and storage device groups using three-dimensional bin-packing techniques with the dimensions defined as virtual slots, controller processor utilization, and inter-set link utilization.

16. A storage system according to claim 12 further comprising:

a process executable in the processor that optimizes the allocation of controllers and storage device groups using a custom heuristic algorithm.

17. A storage system according to claim 12 further comprising:

a process executable in the processor that optimizes the allocation of controllers and storage device groups using selection from among a set of pre-planned controller to storage device group association patterns.

18. A storage system according to claim 12 wherein:

the plurality of controllers are configured as a plurality of controller pairs with a storage array having a restrictive physical association with one controller pair.

19. A storage system according to claim 12 wherein:

the plurality of storage arrays are grouped for Redundant Array of Independent Disks (RAID) style redundancy algorithms with group membership determined according to algorithms resident in a controller that is currently in control of the group.

20. A storage system according to claim 12 further comprising:

controller memory resources administered as virtual slots for placement of group related control and data.

21. A storage system according to claim 20 further comprising:

battery-backed memories included in the virtual slots; and

a process that mirrors information in the battery-backed memories from a primary controller to a secondary controller to maintain continuous data access in conditions of a controller failure event without storage device group movement.

22. A storage system according to claim 20 wherein:

at least one virtual slot sufficiently large to accommodate the largest storage device group is available when no storage device group movement is in progress.

23. A storage system according to claim 12 wherein:

a controller'"'"'s internal bandwidth is sufficient to accommodate full utilization of all external bandwidth impinging on the controller.

24. A storage system according to claim 12 further comprising:

a network configured as multiple sets of associated controller pairs and storage shelves, the individual sets having a bandwidth adequate for accessing all storage arrays in the set, bandwidth between sets being limited.

25. A storage system according to claim 24 wherein:

all interaction with a storage element other than support of access to data or metadata contained on the storage element involves a controller in the same set as the storage element, support of access.

26. An article of manufacture comprising:

a controller usable medium having a computable readable program code embodied therein for moving a virtual storage segment in a storage system from a previous location to a target location, the computable readable program code further comprising;

a code capable of causing the controller to determine performance demand among a plurality of storage device groups;

a code capable of causing the controller to distribute performance demand values according to controller processor utilization of the individual storage device groups and bandwidth utilization pro-ratable among storage device groups within a set; and

a code capable of causing the controller to associate the plurality of storage device groups with controllers based on the performance demand value distributions.

27. A storage system comprising:

means for allocating control of virtual storage segments in a storage system among a plurality of controllers, the storage system being arranged as multiple sets of associated controllers and storage devices;

means for determining performance demand among a plurality of storage device groups;

means for distributing performance demand values according to controller processor utilization of the individual storage device groups and bandwidth utilization pro-ratable among storage device groups within a set; and

means for associating the plurality of storage device groups with controllers based on the performance demand value distributions.

28. A storage system comprising:

a plurality of storage arrays configurable into a plurality of storage device groups;

a plurality of controllers selectively coupled to ones of the storage arrays;

a network fabric arranged as a linkage of multiple sets of associated controllers and storage devices; and

a communication linkage among the plurality of storage arrays across set boundaries.