I/O LATENCY AND IOPS PERFORMANCE IN THIN PROVISIONED VOLUMES

• US 20140359245A1
• Filed: 06/04/2013
• Published: 12/04/2014
• Est. Priority Date: 06/04/2013
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: JONES, CARL E., Roy, Subhojit
• Granted Patent: US 9,639,459 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 2212/6028 Prefetching based on hints or prefetch instructions
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A storage system receives an anticipatory write command corresponding to a potential subsequent write command to be received by the storage system, wherein the anticipatory write command indicates an anticipated region of logical address space that may be written to by the potential subsequent write command. The storage system determines that physical storage is not allocated to the anticipated region of logical address space. The storage system allocates physical storage to the anticipated region of logical address space from a pool of available storage managed by the storage system. The storage system creates an association between the anticipated region of logical address space and the allocated physical storage in a virtual-to-physical mapping.

Claims

1. A method comprising:

receiving, at a storage system, an anticipatory write command corresponding to a potential subsequent write command to be received by the storage system, wherein the anticipatory write command indicates an anticipated write region of logical address space that may be written to by the potential subsequent write command;

determining, by one or more computer processors, that physical storage is not allocated to the anticipated write region of logical address space;

allocating physical storage to the anticipated write region of logical address space from a pool of available storage managed by the storage system; and

creating an association between the anticipated write region of logical address space and the allocated physical storage in a virtual-to-physical mapping.

2. The method of claim 1, further comprising:

receiving, at the storage system, an anticipatory read command corresponding to a potential subsequent read command to be received by the storage system, wherein the anticipatory read command indicates an anticipated read region of logical address space from which data may be read by the potential subsequent read command;

determining, by one or more computer processors, that a virtual-to-physical mapping, associating the anticipated read region of logical address space with physical storage, is not cached in memory; and

caching at least the virtual-to-physical mapping, associating the anticipated read region of logical address space with physical storage, in memory.

3. The method of claim 1, further comprising:

subsequent to allocating physical storage to the anticipated write region of logical address space, receiving a subsequent write command, wherein the subsequent write command instructs data to be written to the anticipated write region of logical address space; and

writing the data to the anticipated write region of logical address space.

4. The method of claim 1, further comprising, marking the physical storage allocated to the anticipated write region of logical address space to be deallocated after a specified duration of time has passed.

5. The method of claim 4, further comprising:

receiving a subsequent write command instructing data to be written to the anticipated write region of logical address space, and in response, unmarking the physical storage allocated to the anticipated write region of logical address space.

6. The method of claim 4, further comprising:

determining, by one or more computer processors, that the specified duration of time has passed; and

deallocating the physical storage allocated to the anticipated write region of logical address space.

7. The method of claim 1, further comprising:

prior to receiving the anticipatory write command;

an application determining a potential subsequent write command to be issued by the application;

the application creating the anticipatory write command based on the determined potential subsequent write command; and

the application sending the anticipatory write command to the storage system.

8. The method of claim 7, further comprising the application selecting a time to send the anticipatory write command to the storage system based on historical input/output patterns of the application.

9. The method of claim 1,

wherein the anticipatory write command is an overloaded write same command;

and

wherein receipt of an overloaded write same command indicates to the storage system that if logical address space referenced by a write same command is associated with physical storage, the storage system should deallocate the physical storage, and if logical address space referenced by the write same command is not associated with physical storage, the storage system should allocate physical storage to the referenced logical address space.

10. A computer system comprising:

one or more computer processors;

one or more computer-readable storage media;

program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, the program instructions comprising;

program instructions to receive an anticipatory write command corresponding to a potential subsequent write command to be received by the computer system, wherein the anticipatory write command indicates an anticipated write region of logical address space that may be written to by the potential subsequent write command;

program instructions to determine that physical storage is not allocated to the anticipated write region of logical address space;

program instructions to allocate physical storage to the anticipated write region of logical address space from a pool of available storage from the one or more computer-readable storage media; and

program instructions to create an association between the anticipated write region of logical address space and the allocated physical storage in a virtual-to-physical mapping.

11. The computer system of claim 10, further comprising program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, to:

receive an anticipatory read command corresponding to a potential subsequent read command to be received by the computer system, wherein the anticipatory read command indicates an anticipated read region of logical address space from which data may be read by the potential subsequent read command;

determine that a virtual-to-physical mapping, associating the anticipated read region of logical address space with physical storage, is not cached in memory; and

cache at least the virtual-to-physical mapping, associating the anticipated read region of logical address space with physical storage, in memory.

12. The computer system of claim 10, further comprising program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, to:

subsequent to allocating physical storage to the anticipated write region of logical address space, receive a subsequent write command, wherein the subsequent write command instructs data to be written to the anticipated write region of logical address space; and

write the data to the anticipated write region of logical address space.

13. The computer system of claim 10, further comprising program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, to mark the physical storage allocated to the anticipated write region of logical address space to be deallocated after a specified duration of time has passed.

14. The computer system of claim 13, further comprising program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, to:

receive a subsequent write command instructing data to be written to the anticipated write region of logical address space, and in response, unmark the physical storage allocated to the anticipated write region of logical address space.

15. The computer system of claim 13, further comprising program instructions, stored on at least one of the one or more computer-readable storage media for execution by at least one of the one or more computer processors, to:

determine that the specified duration of time has passed; and

in response to determining that the specified duration of time has passed, deallocate the physical storage allocated to the anticipated write region of logical address space.

16. A computer program product comprising:

one or more computer-readable storage media;

program instructions, stored on the one or more computer-readable storage media, the program instructions comprising;

program instructions to receive, at a storage system, an anticipatory write command corresponding to a potential subsequent write command to be received by the storage system system, wherein the anticipatory write command indicates an anticipated write region of logical address space that may be written to by the potential subsequent write command;

program instructions to determine that physical storage is not allocated to the anticipated write region of logical address space;

program instructions to allocate physical storage to the anticipated write region of logical address space from a pool of available storage managed by the storage system; and

program instructions to create an association between the anticipated write region of logical address space and the allocated physical storage in a virtual-to-physical mapping.

17. The computer program product of claim 16, further comprising program instructions, stored on the one or more computer-readable storage media, to:

receive, at the storage system, an anticipatory read command corresponding to a potential subsequent read command to be received by the storage system, wherein the anticipatory read command indicates an anticipated read region of logical address space from which data may be read by the potential subsequent read command;

determine that a virtual-to-physical mapping, associating the anticipated read region of logical address space with physical storage, is not cached in memory; and

cache at least the virtual-to-physical mapping, associating the anticipated read region of logical address with physical storage, in memory.

18. The computer program product of claim 16, further comprising program instructions, stored on the one or more computer-readable storage media, to mark the physical storage allocated to the anticipated write region of logical address space to be deallocated after a specified duration of time has passed.

19. The computer program product of claim 18, further comprising program instructions, stored on the one or more computer-readable storage media, to:

receive a subsequent write command instructing data to be written to the anticipated write region of logical address space, and in response, unmark the physical storage allocated to the anticipated write region of logical address space.

20. The computer program product of claim 18, further comprising program instructions, stored on the one or more computer-readable storage media, to:

determine that the specified duration of time has passed; and

in response to determining that the specified duration of time has passed, deallocate the physical storage allocated to the anticipated write region of logical address space.