Hierarchical performance system for managing a plurality of storage units with different access speeds

• US 6,032,224 A
• Filed: 12/03/1996
• Issued: 02/29/2000
• Est. Priority Date: 12/03/1996
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Blumenau, Steven M.
• Primary Examiner(s): Peikari, B. James
• Application Number:
  US08/757,124
• Time in Patent Office: 1,183 Days
• Field of Search: 711/117, 711/154, 711/159, 711/202, 711/203, 711/206, 711/207, 711/208, 711/167, 395/200.47, 395/200.48, 395/200.49, 710/58, 710/60, 710/15, 710/16, 710/25
• US Class Current: 711/117
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/217 Hybrid disk, e.g. using both magnetic and solid state storage devices
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems

Abstract

A computer having capabilities for hierarchical storage of data, said computer including an interpreter that maps logical user read and write requests to physical block level read and write requests, and a hierarchical performance driver having a disk driver interface for receiving the block level read and write requests from the interpreter, the hierarchical performance driver issuing instructions to read and write data from plural data storage devices in response to block level read and write requests, plural data storage devices having different data access speeds, the hierarchical performance driver monitoring the rates of access of blocks of data stored on the data storage devices and transferring blocks of data accessed infrequently from a faster data storage device to a slower data storage device.

Claims

1. A computer having capabilities for hierarchical storage of data stored on plural data storage devices comprising physical media, said computer comprising

an interpreter that maps logical user read and write requests to physical block level read and write requests, each block being the smallest set of data that can be accessed on said physical media, said physical block level read and write requests indicating block numbers for data being requested, and

a hierarchical performance driver having a disk driver interface for receiving said block level read and write requests from said interpreter, said hierarchical performance driver mapping said block numbers into physical blocks at relevant storage devices at which the blocks are actually stored, said hierarchical performance driver issuing instructions to read and write data from said plural data storage devices in response to said block level read and write requests, said plural data storage devices having different data access speeds, said hierarchical performance driver monitoring the rates of access of blocks of individual data stored on said data storage devices and transferring blocks of data from one said data storage device to another said data storage device as a function of the monitored rates of access.

2. The computer of claim 1 wherein said hierarchical performance driver maintains a location map table mapping said block numbers provided by said interpreter to said physical blocks at relevant storage devices at which the blocks are actually stored.

3. The computer of claim 1 wherein said hierarchical performance driver maintains an access rate table for each said storage device, said access rate table listing blocks within the storage device and a rate of access specifying the number of accesses per unit time for each block.

4. The computer of claim 3 wherein each storage device has assigned to it a storage device access rate that defines a threshold that triggers moving a block from one storage device to another.

5. The computer of claim 4 wherein said hierarchical performance driver adjusts said storage device access rates for a storage device in response to rates of access for blocks in the next fastest storage device.

6. The computer of claim 1 wherein said interpreter comprises a file system of an operating system of said computer.

7. The computer of claim 1 wherein said interpreter comprises a database server application.

8. The computer of claim 1 wherein said plural data storage devices include local data storage devices and remote data storage devices, and further comprising a remote storage access system, said hierarchical performance driver also having an operating system device driver application programming interface to said remote storage access system, said remote storage access system being implemented in the user space of said computer and communicating with said remote data storage devices.

9. The computer of claim 8 wherein said remote storage access system and said hierarchical performance driver communicate via IOCTL messages.

10. The computer of claim 1 wherein said plural data storage devices include local data storage devices and remote data storage devices, and further comprising local storage drivers that receive said instructions and provide control signals to control respective said local storage devices.

11. The computer of claim 10 wherein said local storage devices include a solid state disk and a local disk.

12. The computer of claim 10 wherein said local storage includes a local tape.

13. A computer implemented method of providing hierarchical storage of data stored on plural data storage devices comprising physical media, said method comprising

mapping logical user read and write requests to physical block level read and write requests at an interpreter of said computer, each block being the smallest set of data that can be accessed on said physical media, said physical block level read and write requests indicating block numbers for data being requested,

receiving said block level read requests from said interpreter at a hierarchical performance driver having a disk driver interface, said hierarchical performance driver mapping said block numbers into physical blocks at relevant storage devices at which the blocks are actually stored,

issuing, at said hierarchical performance driver, instructions to read and write data from said plural data storage devices in response to said block level read and write requests and said mapping of block numbers, said plural data storage devices having different data access speeds,

monitoring, at said hierarchical performance driver, the rates of access for individual blocks of data stored on said data storage devices, and

transferring blocks of data from one said data storage device to another said data storage device as a function of the monitored rates of access.

14. The method of claim 13 further comprising, maintaining a location map table mapping said block numbers provided by said interpreter to said physical blocks at relevant storage devices at which the blocks are actually stored.

15. The method of claim 13 wherein said monitoring includes maintaining, at said hierarchical performance driver, an access rate table for each said storage device, said access rate table listing blocks within the storage device and the number of accesses per unit time for each block.

16. The method of claim 15 further comprising assigning a storage device access rate to each storage device, said storage device access rate defining a threshold that triggers moving a block from one storage device to another.

17. The method of claim 16 further comprising adjusting a said storage device access rate for a storage device in response to access rates of blocks in the next fastest storage device.

18. The method of claim 13 wherein said interpreter comprises a file system of an operating system of said computer.

19. The method of claim 13 wherein said interpreter comprises a database server application.

20. The method of claim 13 wherein said plural data storage devices include local data storage devices and remote data storage devices, and said remote data storage devices are accessed by a remote storage access system, said hierarchical performance driver also having an operating system device driver application programming interface to said remote storage access system, said remote storage access system being implemented in user space of said computer and communicating with said remote data storage devices.

21. The method of claim 20 wherein said remote storage access system and said hierarchical performance driver communicate via IOCTL messages.

22. A computer program for implementation on a computer to provide hierarchical storage of data stored on plural data storage devices comprising physical media, said computer program residing on a computer-readable medium, said computer having an interpreter that maps logical user read and write requests to physical block level read and write requests, each block being the smallest set of data that can be accessed on said physical media, said physical block level read and write requests indicating block numbers for data being requested,

said computer program comprising instructions causing said computer to create a hierarchical performance driver having a disk driver interface for receiving said block level read and write requests from said interpreter, said hierarchical performance driver mapping said block numbers into physical blocks at relevant storage devices at which the blocks are actually stored, said hierarchical performance driver issuing instructions to read and write data from said plural data storage devices in response to said block level read and write requests, said plural data storage devices having different data access speeds, said hierarchical performance driver monitoring the rates of access of individual blocks of data stored on said data storage devices and transferring blocks of data from one said storage device to another said data storage device as a function of the monitored rates of access.

23. The computer program of claim 22 wherein said interpreter is a file system of an operating system of said computer.

24. The computer program of claim 22 wherein said interpreter is a database server application.

25. The computer program of claim 22 wherein said plural data storage devices include local data storage devices and remote data storage devices, and wherein said computer program further comprises instructions causing said computer to create a remote storage access system, said hierarchical performance driver also having an operating system device driver application programming interface to said remote storage access system, said remote storage access system being implemented in user space of said computer and communicating with said remote data storage devices.

26. The computer program of claim 25 wherein said remote storage access system and said hierarchical performance driver communicate via IOCTL messages.

27. A computer system providing distributed hierarchical storage of computer data stored on plural data storage devices comprising physical media comprising

a network,

one or more remote data storage devices that are connected to said network,

a computer that is connected to said network, said computer comprising

an interpreter that maps logical user write requests to physical block level write requests, each block being the smallest set of data that can be accessed on said physical media, said physical block level read and write requests indicating block numbers for data being requested,

one or more local data storage devices, and

a hierarchical performance driver having a disk driver interface for receiving said block level read and write requests from said interpreter, said hierarchical performance driver mapping said block numbers into physical blocks at relevant storage devices at which the blocks are actually stored, said hierarchical performance driver issuing instructions to read and write data from said data storage devices in response to said block level read and write requests, said data storage devices having different data access speeds, said hierarchical performance driver monitoring the rates of access of individual blocks of data stored on said data storage devices and transferring blocks of data from one said data storage device to another said data storage device as a function of the monitored rates of access.