VIRTUAL COPY AND VIRTUAL WRITE OF DATA IN A STORAGE DEVICE

• US 20120005557A1
• Filed: 06/30/2010
• Published: 01/05/2012
• Est. Priority Date: 06/30/2010
• Status: Abandoned Application

• Current Assignee: SanDisk IL Ltd. (Western Digital Corporation)
• Original Assignee: SanDisk IL Ltd. (Western Digital Corporation)
• Inventors: Mardiks, Eitan, Erez, Eran
• Application Number:
  US12/828,029
• Publication Number:
  US 20120005557A1
• Time in Patent Office: Days
• US Class Current: 714/763
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: H03M 13/63 Joint error correction and other techniques H03M13/31 and H03M13/33 take precedence

Abstract

A storage device with a memory and a controller, and a method of copying data on a storage device are provided to perform virtual copy and virtual write of data in a storage device without physically storing data in the storage device. The controller includes, or incorporates with an executable module that handles a command to copy data from a source logical address to a destination logical address, where the source logical memory address data is already associated with a first physical memory address storing the data.

Claims

1. A method of copying data on a storage device, comprising:

in a storage device including a memory and a controller for managing the memory, wherein the controller includes a first executable module, and wherein data are stored in the memory in physical memory addresses that are associated with logical memory addresses, performing by the first executable module;

receiving a command to copy data from a source logical memory address to a destination logical memory address, the source logical memory address data being already associated with a first physical memory address storing the data; and

in response to receiving the command, associating the first physical memory address with the destination logical memory address such that the data stored in the first physical memory address is accessible by using the source logical memory address or the destination logical memory address.

2. The method of claim 1, wherein subsequent to associating the first physical memory address with the destination logical memory address, the first physical memory address is associated at least with the source logical memory address and the destination logical memory address.

3. The method of claim 1, wherein receiving the command comprises receiving a copy command from a host device in communication with the storage device.

4. The method of claim 1, wherein the controller further includes a second executable module, the controller executing the second executable module to identify whether a previous copy of the data is stored in the storage device.

5. The method of claim 4, wherein receiving the command comprises receiving a write command from a host device in communication with the storage device, and executing a virtual copy procedure within the storage device when the second executable module identifies the previous copy of the data in the storage device.

6. The method of claim 5, wherein the controller further includes a verification module, the verification module verifying that the previous copy of the data in the storage device is identical to the data received by the command prior to executing the virtual copy procedure.

7. The method of claim 4, wherein identifying the previous copy of the data in the storage device involves performing hash operations.

8. The method of claim 7, wherein the second executable module utilizes an error correction code (ECC) for performing the hash operations.

9. The method of claim 1, wherein when the command comprises a write command for new data and identifies a destination logical address currently associated with the first physical address, and the first physical address is already associated with at least two logical addresses, the method further comprises:

allocating a free physical address for the new data;

writing the new data to the allocated free physical address; and

associating the destination logical address with the allocated free physical address, wherein the destination logical address and the first physical address are no longer associated.

10. A storage device, comprising:

a memory, where data are stored in physical memory addresses that are associated with logical memory addresses; and

a controller for managing the memory, the controller including a first executable module, the first executable module configured to;

receive a command to copy data from a source logical memory address to a destination logical memory address, the source logical memory address data being already associated with a first physical memory address storing the data; and

in response to the received command, associate the first physical memory address with the destination logical memory address such that the data stored in the first physical memory address is accessible by using either one of the source logical memory address and the destination logical memory address.

11. The storage device of claim 10, wherein subsequent to associating the first physical memory address with the destination logical memory address, the first physical memory address is associated at least with the source logical memory address and the destination logical memory address.

12. The storage device of claim 11, wherein the command to copy the data is a copy command received from a host device in communication with the storage device.

13. The storage device of claim 11, wherein the controller further includes a second executable module, the second executable module configured to identify a previous copy of the data in the storage device.

14. The storage device of claim 13, wherein the controller is configured to internally generate the command to copy the data, in response to a write command received from a host device in communication with the storage device, upon identification by the second executable module of the previous copy of the data in the storage device.

15. The storage device of claim 13, wherein the controller further includes a verification module operable to verify that the previous copy of the data in the storage device is identical to the data received with the write command.

16. The storage device of claim 13, wherein the second executable module is configured to identify the previous copy of the data in the storage device by performing hash operations.

17. The storage device of claim 16, wherein the second executable module is configured to utilize with an error correction code (ECC) for performing the hash operations.

18. A method of copying data on a storage device, comprising:

in a storage device including a memory and a controller for managing the memory, wherein data are stored in the memory in physical memory addresses that are associated with logical memory addresses, performing by the controller;

receiving a command from a host;

determining if data associated with the command is already stored in the memory; and

in response to determining that the data associated with the command is already stored at a physical address in the memory associated with an existing logical address;

associating a destination logical address contained in the received command with the physical address of the data already stored in the memory, wherein the data is accessible by the host via either the destination logical address or the existing logical address.

19. The method of claim 18, wherein the command comprises a write command and further comprising, in response to determining that the data associated with the write command is not already stored in the memory, writing the data associated with the write command to a physical address in the memory.

20. The method of claim 18, wherein determining if the data associated with the command is already stored comprises the controller generating a data pattern identifier for the data associated with the command and comparing the generated data pattern identifier with previously generated data pattern identifiers for data already stored in the memory.

21. The method of claim 20, wherein generating a data pattern identifier comprises applying a hashing algorithm to the data associated with the command.