Storing information on storage devices having different performance capabilities within a storage system

• US 20060259728A1
• Filed: 05/11/2005
• Published: 11/16/2006
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Williams, James, Pruscino, Angelo, Chandrasekaran, Sashikanth
• Granted Patent: US 7,711,916 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0649 Lifecycle management
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays

Abstract

Techniques are described for storing portions of files on different storage devices based on the devices'"'"' respective storage class. For example, different extents from a large file within a system, application, or database may be stored on different storage devices. The storage devices may be part of a single storage system that includes some storage devices that have different performance capabilities. The decision of where, within the storage classes, to store data may be based on the access patterns of the data. Access patterns regarding file extents are tracked using respective access bits, which are set when a memory block associated with an extent is accessed via an I/O operation. In one embodiment, an access bitmap is modified to account for cached blocks of file extents.

Claims

1. A computer-implemented method comprising:

associating a first storage device within a storage system with a first storage class;

associating a second storage device within the storage system with a second storage class;

wherein the first and second storage classes are based on the respective performance capabilities of at least the first and second storage devices, and wherein the first storage device has different performance capabilities than the second storage device; and

storing first data from a first extent, of a plurality of extents associated with a data file, in the first storage device; and

storing second data from a second extent, of the plurality of extents, in the second storage device;

wherein the decision of where to store the first and second data is made automatically based, at least in part, on the respective storage classes with which the first and second storage devices are associated.

2. The method of claim 1, further comprising:

automatically migrating, from the first storage device to the second storage device, third data from a third extent of the plurality of extents, while keeping the first data stored on the first storage device;

wherein the decision to migrate the third data is made automatically based, at least in part, on the respective storage classes to which the first and second storage devices are associated.

3. The method of claim 2, wherein the second storage device has lesser performance capabilities than the first storage device, and wherein the third data is less frequently accessed than the first data, and wherein migrating the third data to the second storage device is based on the second storage device having lesser performance capabilities and the third data being less frequently accessed.

4. The method of claim 3, wherein the decision to migrate the third data is based, at least in part, on a policy that associates a particular data access threshold with the second storage class.

5. The method of claim 1, further comprising:

associating a third storage device that is new to the storage system with a third storage class, wherein the third storage device has better performance capabilities than the first storage device;

automatically migrating, from the first storage device to the third storage device, third data within a third extent of the plurality of extents, while keeping the first data stored on the first storage device, wherein the third data is more frequently accessed than the first data; and

wherein the decision to migrate the third data to the third storage device is made automatically based, at least in part, on the third storage device having more performance capabilities and the third data being more frequently accessed.

6. The method of claim 1, wherein the first and second storage devices are separate disk storage devices within a single storage system.

7. The method of claim 1, further comprising:

automatically determining the performance capabilities of the first storage device;

automatically determining the performance capabilities of the second storage device;

wherein the step of associating the first storage device with the first storage class includes automatically associating the first storage device with the first storage class based on the automatically determined performance capabilities of the first storage device; and

wherein the step of associating the second storage device with the second storage class includes automatically associating the second storage device with the second storage class based on the automatically determined performance capabilities of the second storage device.

8. The method of claim 1, further comprising:

creating a first virtual sub-directory, of a directory associated with the storage system, for referencing storage devices associated with the first storage class; and

creating a second virtual sub-directory, of the directory associated with the storage system, for referencing storage devices associated with the second storage class.

9. The method of claim 1, further comprising:

in response to an I/O operation involving a persistent memory block corresponding to the first extent, setting an access bit to indicate an I/O operation involved the first extent.

10. The method of claim 1, further comprising:

monitoring which persistent memory blocks in which the file is stored are involved in one or more I/O operations;

for extents, of the plurality of extents, that have a corresponding persistent memory block that was involved in an I/O operation, setting a respective access bit to indicate an I/O operation involved that extent; and

generating an access bitmap for the file based on the access bits.

11. The method of claim 10, further comprising:

generating a cached extent bitmap to indicate which extents, of the plurality of extents, have at least a portion of corresponding data cached in cache memory; and

generating a migration bitmap based on the access bitmap and the cached extent bitmap, to indicate which extents do not have any corresponding persistent memory blocks that were involved in an I/O operation and from which no portion of corresponding data was cached in cache memory.

12. The method of claim 11, further comprising:

automatically migrating, from the first storage device to the second storage device, third data from a third extent of the plurality of extents, while keeping the first extent stored on the first storage device;

wherein the decision to migrate the third data is made automatically based, at least in part, on the respective storage classes to which the first and second storage devices are associated and on the migration bitmap.

13. The method of claim 1, further comprising:

reading a user-specified association between the first data and the first storage class and a user-specified association between the second data and the second storage class; and

wherein storing the first data and storing the second data are performed in response to reading the user-specified associations.

14. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

15. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

16. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

17. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

18. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

19. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

20. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

21. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

22. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

23. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.

24. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 11.

25. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 12.

26. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 13.

27. A computer-implemented method comprising:

monitoring, for a period of time, which persistent memory blocks in which a data container is stored are involved in an I/O operation;

for extents, of a plurality of extents associated with the container, that have a corresponding persistent memory block that was involved in an I/O operation during the period of time, setting a respective access bit to indicate an I/O operation involved that extent;

generating a first bitmap for the container based on the access bits, to indicate which extents of the plurality of extents were accessed during the period of time;

generating a second bitmap to indicate which extents, of the plurality of extents, have at least a portion of corresponding data cached in cache memory; and

generating a third bitmap based on the first and second bitmaps, to indicate which extents do not have any corresponding persistent memory blocks that were involved in an I/O operation and from which no portion of corresponding data was cached in cache memory.

28. A machine-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 27.