Systems and methods for managing stalled storage devices

• US 7,870,345 B2
• Filed: 03/27/2008
• Issued: 01/11/2011
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Isilon Systems Incorporated (Dell Technologies Inc.)
• Inventors: Akidau, Tyler A., Daud, Asif, Maykov, Ilya, Passey, Aaron J.
• Primary Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US12/057,302
• Publication Number:
  US 20090249013A1
• Time in Patent Office: 1,020 Days
• Field of Search: 711/100, 711/110, 711/147, 711/148, 711/152, 711/158, 707/100
• US Class Current: 711/147
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• 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 11/2094 Redundant storage or storage space G06F11/2056 takes precedence

Abstract

Embodiments relate to systems and methods for managing stalled storage devices of a storage system. In one embodiment, a method for managing access to storage devices includes determining that a first storage device, which stores a first resource, is stalled and transitioning the first storage device to a stalled state. The method also includes receiving an access request for at least a portion of the first resource while the first storage device is in the stalled state and attempting to provide access to a representation of the portion of the first resource from at least a second storage device that is not in a stalled state. In another embodiment, a method of managing access requests by a thread for a resource stored on a storage device includes initializing a thread access level for an access request by a thread for the resource. The method also includes determining whether the storage device, which has a device access level, is accessible based at least in part on the thread access level and the device access level and selecting a thread operation based at least in part on the determination of whether the storage device is accessible. The thread operation may be selected from attempting the thread access request if the device is accessible and determining whether to restart the thread access request if the device is not accessible.

Claims

1. A method of managing access requests by a thread for a resource stored on a storage device, the method comprising:

initializing a thread access level for an access request by a thread for a resource stored on a storage device, the storage device having a device access level;

determining whether the storage device is accessible based at least in part on the thread access level and the device access level; and

selecting a thread operation based at least in part on the determination of whether the storage device is accessible, the thread operation selected from attempting the thread access request if the device is accessible and determining whether to restart the thread access request if the device is not accessible.

2. The method of managing access requests of claim 1, wherein initializing the thread access level comprises initializing a current thread access level and a desired thread access level.

3. The method of managing access requests of claim 2, wherein determining whether the storage device is accessible comprises comparing the current thread access level and the device access level.

4. The method of managing access requests of claim 3, wherein if the storage device is determined not to be accessible, the method further comprises updating the desired thread access level based at least in part on the desired thread access level, the current thread access level, and the device access level.

5. The method of managing access requests of claim 1, wherein if the thread operation is selected to be attempting the thread access request, the method further comprises determining whether the thread access request was successful.

6. The method of managing access requests of claim 5, wherein if the thread access request is not determined to be successful, the method further comprises determining whether to restart the thread access request.

7. The method of managing access requests of claim 1, wherein determining whether to restart the thread access request is based at least in part on the thread access level and the device access level.

8. A system of managing access requests by a thread for a resource stored on a storage device, the system comprising:

a storage device for storing a resource; and

a software module configured to;

initialize a thread access level for an access request by a thread for a resource stored on a storage device, the storage device having a device access level;

determine whether the storage device is accessible based at least in part on the thread access level and the device access level; and

select a thread operation based at least in part on whether the storage device is determined to be accessible, the thread operation selected from attempting the thread access request if the device is accessible and determining whether to restart the thread access request if the device is not accessible.

9. The system of claim 8, wherein to initialize the thread access level, the software module is further configured to initialize a current thread access level and a desired thread access level.

10. The system of claim 9, wherein to determine whether the storage device is accessible, the software module is further configured to compare the current thread access level and the device access level.

11. The system of claim 10, wherein if the storage device is determined not to be accessible, the software module is further configured to update the desired thread access level based at least in part on the desired thread access level, the current thread access level, and the device access level.

12. The system of claim 8, wherein if the thread operation is selected to be attempting the thread access request, the software is further configured to determine whether the thread access request was successful.

13. The system of claim 12, wherein if the thread access request is not determined to be successful, the software module is further configured to determine whether to restart the thread access request.

14. The system of claim 8, wherein the software module is further configured to determine whether to restart the thread access request based at least in part on the thread access level and the device access level.

15. A computer-readable medium having stored thereon executable instructions that, when executed by a processor, cause the processor to perform a method of managing access requests by a thread for a resource stored on a storage device, the method comprising:

initializing a thread access level for an access request by a thread for a resource stored on a storage device, the storage device having a device access level;

determining whether the storage device is accessible based at least in part on the thread access level and the device access level; and

selecting a thread operation based at least in part on the determination of whether the storage device is accessible, the thread operation selected from attempting the thread access request if the device is accessible and determining whether to restart the thread access request if the device is not accessible.