THIN PROVISIONING IN A STORAGE DEVICE

• US 20150127923A1
• Filed: 11/06/2013
• Published: 05/07/2015
• Est. Priority Date: 11/06/2013
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Miller, Ethan, Colgrove, John, Hayes, John
• Granted Patent: US 10,365,858 B2
• Time in Patent Office: Days
• US Class Current: 711/206
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 12/1036 for multiple virtual address spaces, e.g. segmentation G06F12/1045 takes precedence
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays

Abstract

An apparatus, method, and computer-readable storage medium for allowing a block-addressable storage device to provide a sparse address space to a host computer. The storage device exports an address space to a host computing device which is larger than the storage capacity of the storage device. The storage device translates received file system object addresses in the larger address space to physical locations in the smaller address space of the storage device. This allows the host computing device more flexibility in selecting addresses for file system objects which are stored on the storage device.

Claims

1. A storage device comprising:

a first number of addressable storage locations, wherein each addressable storage location of the first number of addressable storage locations is configured to store a block of data; and

a translation layer configured to;

utilize a first protocol to communicate with a host computing device, wherein the first protocol addresses blocks with a fixed-width address, and wherein the first protocol supports only a single volume per storage device; and

export an address space to the host computing device, wherein the address space has a second number of addressable storage locations, wherein the second number is greater than the first number.

2. The storage device as recited in claim 1, wherein the first protocol is Serial Advanced Technology Attachment (SATA), Small Computer System Interface (SCSI) or Serial Attached SCSI (SAS).

3. The storage device as recited in claim 1, wherein the translation layer is further configured to allow the host computing device to write to a first address, wherein the first address has a value larger than a capacity of the storage device.

4. The storage device as recited in claim 1, wherein the translation layer is further configured to maintain a mapping table to map addresses in the exported address space to addressable storage locations on the storage device.

5. The storage device as recited in claim 4, wherein each address in the exported address space comprises a file system object number concatenated with an offset number, wherein the offset number corresponds to an offset of a data block within the file system object.

6. The storage device as recited in claim 1, wherein the storage device is further configured to:

receive a first query from the host computing device requesting a capacity of the storage device; and

responsive to receiving the first query, returning a first value to the host computing device, wherein the first value overstates the capacity of the storage device.

7. The storage device as recited in claim 1, wherein the translation layer utilizes N address bits to address storage locations on the storage device, wherein the exported address space utilizes M address bits, wherein M and N are positive integers, and wherein M is greater than N

8. A method comprising:

utilizing a first protocol to communicate between a storage device and a host computing device, wherein the first protocol addresses blocks with a fixed-width address, and wherein the first protocol supports only a single volume per storage device; and

exporting an address space from the storage device to the host computing device, wherein the address space has a first number of addressable storage locations, wherein the first number is greater than a capacity of addressable storage locations on the storage device.

9. The method as recited in claim 8, wherein the first protocol is Serial Advanced Technology Attachment (SATA), Small Computer System Interface (SCSI) or Serial Attached SCSI (SAS).

10. The method as recited in claim 8, further comprising allowing the host computing device to write to a first address, wherein the first address has a value larger than the capacity of addressable storage locations on the storage device.

11. The method as recited in claim 8, further comprising maintaining a mapping table on the storage device to map addresses in the exported address space to addressable storage locations on the storage device.

12. The method as recited in claim 11, wherein each address in the exported address space comprises a file system object number concatenated with an offset number, wherein the offset number corresponds to an offset of a data block within the file system object.

13. The method as recited in claim 8, further comprising:

receiving a first query from the host computing device at the storage device requesting a capacity of the storage device; and

responsive to receiving the first query, returning a first value to the host computing device, wherein the first value overstates the capacity of the storage device.

14. The method as recited in claim 8, wherein the storage device comprises a translation layer, wherein the translation layer utilizes N address bits to address storage locations on the storage device, wherein the exported address space utilizes M address bits, wherein M and N are positive integers, and wherein M is greater than N

15. A non-transitory computer readable storage medium comprising program instructions, wherein the program instructions are executable to:

utilize a first protocol to communicate between a storage device and a host computing device, wherein the first protocol addresses blocks with a fixed-width address, and wherein the first protocol supports only a single volume per storage device; and

export an address space from the storage device to the host computing device, wherein the address space has a first number of addressable storage locations, wherein the first number is greater than a capacity of addressable storage locations on the storage device.

16. The non-transitory computer readable storage medium as recited in claim 15, wherein the first protocol is Serial Advanced Technology Attachment (SATA), Small Computer System Interface (SCSI) or Serial Attached SCSI (SAS).

17. The non-transitory computer readable storage medium as recited in claim 15, wherein the program instructions are further executable to allow the host computing device to write to a first address, wherein the first address has a value larger than a capacity of the storage device.

18. The non-transitory computer readable storage medium as recited in claim 15, wherein the program instructions are further executable to maintain a mapping table on the storage device to map addresses in the exported address space to addressable storage locations on the storage device.

19. The non-transitory computer readable storage medium as recited in claim 18, wherein each address in the exported address space comprises a file system object number concatenated with an offset number, wherein the offset number corresponds to an offset of a data block within the file system object.

20. The non-transitory computer readable storage medium as recited in claim 15, wherein the program instructions are further executable to:

receive a first query from the host computing device requesting a capacity of the storage device; and

responsive to receiving the first query, returning a first value to the host computing device, wherein the first value overstates the capacity of the storage device.