Critical resource management

• US 7,934,027 B2
• Filed: 01/19/2007
• Issued: 04/26/2011
• Est. Priority Date: 01/19/2007
• 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: Rodriguez, Richard B., Cooke, Thomas
• Primary Examiner(s): Tsai; Henry W
• Assistant Examiner(s): Nam; Hyun
• Application Number:
  US11/655,456
• Publication Number:
  US 20080178188A1
• Time in Patent Office: 1,558 Days
• Field of Search: 710/54, 718/104
• US Class Current: 710/54
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 67/1097 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]

Abstract

In one embodiment, a method of managing critical resource usage in a storage network comprises receiving, in a storage controller, an input/output operation from a host, wherein the input/output operation identifies a storage unit, placing the input/output operation in a waiting queue, determining a maximum queue depth for at least one critical resource in the storage network required to execute the input/output command against the storage unit, and blocking one or more subsequent input/output commands from the host for the storage unit when the wait queue for the critical resource exceeds the maximum queue depth.

Claims

1. A method of managing critical resource usage in a storage network comprising:

monitoring a queue depth for a critical resource having a maximum queue depth;

receiving an I/O (input/output) operation from a host for the critical resource;

executing the I/O operation when the queue depth is below a threshold;

calculating a new maximum queue depth for the critical resource when the queue depth for the critical resource exceeds the threshold;

receiving a subsequent I/O operation from the host for the critical resource;

placing the subsequent I/O operation in a waiting queue;

blocking the subsequent I/O operation when the waiting queue has a queue depth that exceeds the new maximum queue depth;

transmitting the new maximum queue depth to a peer storage controller;

receiving, in the peer storage controller, an I/O operation from the host that identifies a storage unit; and

processing the I/O operation using the new maximum queue depth, wherein the new maximum queue depth is calculated by dividing a number of available resources by a number of initiators waiting for the resources.

2. The method of claim 1, further comprising transmitting to the host a message indicating that the subsequent I/O operation has been blocked.

3. The method of claim 1, further comprising:

detecting a drop in usage of the critical resource; and

enabling one or more I/O on the waiting queue.

4. The method of claim 3, further comprising:

enabling one or more subsequent input/output operations.

5. A storage controller, comprising:

a processor;

a memory module comprising logic instructions stored in a computer-readable medium which, when executed by the processor, configure the controller to;

receive, in the storage controller, an input/output operation from a host, wherein the input/output operation identifies a storage unit in a storage network and a critical resource in the storage network has a maximum queue depth;

place the input/output operation in a waiting queue;

determine a new maximum queue depth for the critical resource required to execute the input/output operation against the storage unit;

block one or more subsequent input/output (I/O) operations from the host for the storage unit when the waiting queue for the critical resource exceeds the new maximum queue depth;

transmit the new maximum queue depth to a peer storage controller;

receive, in the peer storage controller, an I/O operation from the host that identifies a storage unit; and

process the I/O operation using the new maximum queue depth, wherein the new maximum queue depth is calculated by dividing a number of available resources by a number of initiators waiting for the resources.

6. The storage controller of claim 5, further comprising logic instructions stored on a computer-readable medium which, when executed, configure the controller to transmit to the host a message indicating that the input/output operation has been blocked.

7. The storage controller of claim 5, further comprising logic instructions stored on a computer-readable medium which, when executed, configure the controller to:

detect a drop in usage of the critical resource; and

enable one or more input/operations on the waiting queue.

8. The storage controller of claim 7, further comprising logic instructions stored on a computer-readable medium which, when executed, configure the controller to:

enable one or more subsequent input/output operations.

9. A computer program product comprising logic instructions stored in a computer-readable storage medium which, when executed by a processor in a storage controller, configure the controller to:

receive, in the storage controller, an input/output operation from a host, wherein the input/output operation identifies a storage unit in a storage network and a critical resource in the storage network has a maximum queue depth;

place the input/output operation in a waiting queue;

determine a new maximum queue depth for the critical resource required to execute the input/output operation against the storage unit;

block one or more subsequent input/output operations from the host for the storage unit when the waiting queue for the critical resource exceeds the new maximum queue depth;

transmit the new maximum queue depth to a peer storage controller;

receive, in a peer storage controller, an input/output operation that from the host that identifies the storage unit; and

process the input/output operation using the new maximum queue depth, wherein the new maximum queue depth is determined by dividing a number of available resources by a number of initiators waiting for the resources.

10. The computer program product of claim 9, further comprising logic instructions stored on a computer-readable storage medium which, when executed, configure the controller to transmit to the host a message indicating that the input/output operation has been blocked.

11. The computer program product of claim 9, further comprising logic instructions stored on a computer-readable storage medium which, when executed, configure the controller to:

detect a drop in usage of the critical resource; and

enable one or more input/operations on the waiting queue.