Data storage systems

• US 20050132150A1
• Filed: 08/30/2004
• Published: 06/16/2005
• Est. Priority Date: 08/28/2003
• Status: Active Grant

• Current Assignee: AirBNB Incorporated
• Original Assignee: International Business Machines Corporation
• Inventors: Huw, Francis Michael, Nicholson, Robert Bruce, Jewell, Colin Robert
• Granted Patent: US 8,397,012 B2
• Time in Patent Office: Days
• US Class Current: 711/154
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/2015 Redundant power supplies power supply failure G06F1/30
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A data storage subsystem includes a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory. The available capacity for such data storage is dynamically allocated between multiple firmware client components of the storage subsystem, such that each client component has its own (varying) allocation of the available capacity. A higher priority for the storage of such data is given to client components on which other client components depend, such as lower layers of the software stack, thereby allowing them to get a larger share of the available capacity for such data storage when needed and complete their input/output requests faster.

Claims

1. An apparatus for controlling a data storage subsystem which comprises a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the apparatus comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory on the basis of the nature of the data to be stored in the volatile memory.

2. An apparatus for controlling a data storage subsystem which comprises a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the apparatus comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory on the basis of the nature of the client component requesting storage of the data in the volatile memory.

3. An apparatus for use in a data storage subsystem, the apparatus comprising:

a volatile memory;

means for preserving data stored in the volatile memory in the event of an interruption in the power supply to the volatile memory;

means for denoting data stored in the volatile memory as being data that should be preserved in the event of a power supply interruption; and

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory on the basis of the nature of the data to be stored and the nature of the client component requesting storage of the data in the volatile memory.

4. The apparatus of claim 3, further comprising means for allocating the available capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of a power supply interruption on the basis of the nature of the data to be stored and the nature of the client component requesting storage of the data.

5. The apparatus of claim 3, further comprising means for allocating to different client components using the volatile memory different priority levels for access to storage capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

6. An apparatus for controlling a data storage subsystem which comprises a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the apparatus comprising:

means for allocating to different client components using the volatile memory different priority levels for access to storage capacity in the volatile memory for data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

7. An apparatus for use in a data storage subsystem, the apparatus comprising:

a volatile memory;

means for preserving data stored in the volatile memory in the event of an interruption in the power supply to the volatile memory;

means for denoting data stored in the volatile memory as being data that should be preserved in the event of a power supply interruption; and

means for allocating to different client components using the volatile memory different priority levels for access to storage capacity in the volatile memory for data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

8. The apparatus of claim 7, wherein firmware client components of the storage subsystem that require the ability to store data in the volatile memory that should be preserved in the event of a power supply interruption to ensure data integrity are given a higher priority for storing such data than client components that only require the ability to store such data for increased performance.

9. The apparatus of claim 7, further comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or client components for processing its input/output requests to the storage subsystem.

10. An apparatus for controlling a data storage subsystem which comprises a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the apparatus comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or components for processing its input/output requests to the storage subsystem.

11. An apparatus for use in a data storage subsystem, the comprising:

a volatile memory;

means for preserving data stored in the volatile memory in the event of an interruption in the power supply to the volatile memory;

means for denoting data stored in the volatile memory as being data that should be preserved in the event of a power supply interruption; and

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or components for processing its input/output requests to the storage subsystem.

12. The apparatus of claim 11, wherein, if a first client component of the storage system is dependent on a second client component to process its write or read operations, the second client component is allocated a higher priority for storing data in the volatile memory that should be preserved in the event of a power supply interruption.

13. The apparatus of claim 12, wherein firmware client components of the storage subsystem include a plurality of software layers in a client component stack, and comprising means for giving the lower layers in the client component stack preferential access to the available capacity in the volatile memory for storing data that can be denoted as being data that should be preserved in the event of a power supply interruption.

14. The apparatus of claim 11, further comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

15. An apparatus for controlling a data storage subsystem which comprises a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the apparatus comprising:

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

16. An apparatus for use in a data storage subsystem, the apparatus comprising:

a volatile memory;

means for preserving data stored in the volatile memory in the event of an interruption in the power supply to the volatile memory;

means for denoting data stored in the volatile memory as being data that should be preserved in the event of a power supply interruption; and

means for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

17. The apparatus of claim 16, wherein the available capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of a power supply interruption is allocated firstly to client components that need to store such data to ensure data integrity, and then once those client components'"'"' needs have been satisfied, to client components on which other client components are dependent to be able to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

18. The apparatus of claim 16, further comprising means for preserving data stored in the volatile memory in the event of an interruption in the power supply to the volatile memory in the form of a temporary power supply, a nonvolatile memory, and means for writing data to the nonvolatile memory using power supplied by the temporary power supply when a power supply interruption is detected.

19. An apparatus for controlling a system in which a pool of finite resource is shared between plural clients that request the use of the resource, the apparatus comprising:

means for controlling access to the pool of resource by clients wishing to use the resource on the basis of the dependency of at least one of the clients on another client or clients for its ability to use the resource.

20. An apparatus for controlling a system in which a pool of finite resource is shared between plural clients that request the use of the resource, the apparatus comprising:

means for controlling access to the pool of resource by clients wishing to use the resource on the basis of the ability of a or more than one of the clients to reduce their use of the resource.

21. A method of operating a data storage subsystem comprising a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the method comprising:

controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory on the basis of the nature of the data to be stored and/or the nature of the client component requesting storage of the data in the volatile memory.

22. The method of claim 21, further comprising allocating the available capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of a power supply interruption on the basis of the nature of the data to be stored and/or the nature of the client component requesting storage of the data.

23. The method of claim 21, further comprising allocating to different client components using the volatile memory different priority levels for access to storage capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

24. A method of operating a data storage subsystem comprising a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the method comprising:

allocating to different client components using the volatile memory different priority levels for access to storage capacity in the volatile memory for data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

25. The method of claim 24, further comprising giving firmware client components of the storage subsystem that require the ability to store data in the volatile memory that should be preserved in the event of a power supply interruption to ensure data integrity a higher priority for storing such data than firmware client components that only require the ability to store such data for increased performance.

26. The method of claim 25, further comprising:

controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or components for processing its input/output requests to the storage subsystem.

27. A method of operating a data storage subsystem comprising a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the method comprising:

controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or components for processing its input/output requests to the storage subsystem.

28. The method of claim 27, wherein, if a first client component of the storage subsystem is dependent on a second client component to process its write or read operations, the second client component is allocated a higher priority for storing data in the volatile memory that should be preserved in the event of a power supply interruption.

29. The method of claim 28, wherein firmware client components of the storage subsystem include a plurality of software layers in a client component stack, and comprising giving the lower layers in the client component stack preferential access to the available capacity in the volatile memory for storing data that can be denoted as being data that should be preserved in the event of a power supply interruption.

30. The method of claim 29, further comprising:

controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

31. A method of operating a data storage subsystem comprising a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the method comprising:

controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

32. The method of claim 31, further comprising allocating the available capacity in the volatile memory for data that can be denoted as being data that should be preserved in the event of a power supply interruption firstly to client components that need to store such data to ensure data integrity, and then once those client components'"'"' needs have been satisfied, to client components on which other client components are dependent to be able to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.

33. A method of operating a system in which a pool of finite resource is shared between plural clients that have requested a use of the resource, the method comprising:

controlling access to the pool of resource by clients wishing to use the resource on the basis of the dependency of at least one of the clients on another client or clients for its ability to use the resource.

34. A method of operating a system in which a pool of finite resource is shared between plural clients that have requested a use of the resource, the method comprising:

controlling access to the pool of resource by clients wishing to use the resource on the basis of the ability of a or more than one of the clients to reduce their use of the resource.

35. A computer program product, residing on a computer usable medium, for use in a data storage subsystem having a volatile memory in which stored data can be denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory, the computer program product comprising:

computer program code for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the dependency of at least one of the client components on another client component or components for processing its input/output requests to the storage subsystem.

36. The computer program product of claim 35, wherein, if a first client component of the storage subsystem is dependent on a second client component to process its write or read operations, the second client component is allocated a higher priority for storing data in the volatile memory that should be preserved in the event of a power supply interruption.

37. The computer program product of claim 36, wherein firmware client components of the storage subsystem include a plurality of software layers in a client component stack, and comprising giving the lower layers in the client component stack preferential access to the available capacity in the volatile memory for storing data that can be denoted as being data that should be preserved in the event of a power supply interruption.

38. The computer program product of claim 37, further comprising:

computer program code for controlling the storage in the volatile memory of data that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory by different firmware client components of the storage subsystem on the basis of the ability of a or more than one of the client components to reduce the amount of data that it or they have stored in the volatile memory that is denoted as being data that should be preserved in the event of an interruption in the power supply to the volatile memory.