Translation layer partitioned between host and controller

Patent metadata

Field	Value
Publication number	US-9329991-B2
Application number	US-201314060799-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Jan 22, 2013
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A method for using a partitioned flash transition layer is disclosed. Step (A) receives, at an apparatus from a host, a write command having first write data. Step (B) generates second write data by compressing the first write data in the apparatus. The second write data generally has a variable size. Step (C) stores the second write data at a physical location in a nonvolatile memory. The physical location is a next unwritten location. Step (D) returns, from the apparatus to the host in response to the write command, an indication of the physical location.

First claim

The invention claimed is:

1. A method of storing data utilizing a partitioned flash translation layer comprising the steps of:
receiving, first data to be written from a host; and
storing second data generated from the first data in a memory, wherein the first data is compressed to generate the second data, the second data has a size that is variable, the second data is stored among a plurality of physical locations in the memory, an initial physical location of the plurality of physical locations that hold the second data is a next unwritten location in the memory, the size of the second data is stored in a first partition of the flash translation layer local to the memory, and the initial physical location of the second data in the memory is stored in a second partition of the flash translation layer in the host.

2. The method according to claim 1 , further comprising the steps of:
receiving a read command having the initial physical location of the second data from the host;
reading the size of the second data from the first partition of the flash translation layer; and
retrieving the second data by reading a portion of the memory based on the initial physical location and the size of the second data.

3. The method according to claim 2 , further comprising the steps of:
recreating the first data by decompressing the second data as retrieved from the memory; and
returning the first data as recreated to the host.

4. The method according to claim 1 , further comprising the step of:
storing an identifier associated with the first data in the memory as at least a portion of a header associated with the second data.

5. The method according to claim 4 , further comprising the step of:
maintaining a map in the host, wherein the map associates the identifier with the initial physical location of the second data in the memory.

6. The method according to claim 4 , wherein the identifier is a logical block address, the initial physical location is an address within one of a plurality of read units in the memory that hold the second data, and each of the plurality of read units comprises a respective portion of the second data and a respective error correction information that protects the respective portion of the second data.

7. The method according to claim 6 , wherein the memory has a plurality of pages, the address is in a first page of the plurality of pages that hold the second data, the first page includes a first number of the plurality of read units that hold the second data, a second page of the plurality of pages includes a second number of the plurality of read units that hold the second data, and the first number is different from the second number.

8. The method according to claim 1 , wherein the next unwritten location adjoins previously written data in a physical address space of the memory.

9. A method of storing data utilizing a partitioned flash translation layer, comprising the steps of:
receiving the data to be written from a host, wherein the data has a size that is variable; and
storing the data in a memory, wherein the data is stored among a plurality of physical locations in the memory, an initial physical location of the plurality of physical locations that hold the data is a next unwritten location in the memory, the size of the data is stored in a first partition of the flash translation layer local to the memory, and the initial physical location of the data in the memory is stored in a second partition of the flash translation layer in the host.

10. The method according to claim 9 , further comprising the steps of:
receiving a read command having the initial physical location in the memory that holds the data from the host;
reading the size of the data from the first partition of the flash translation layer; and
retrieving the data by reading a portion of the memory based on the initial physical location and the size of the data.

11. The method according to claim 10 , further comprising the step of:
returning the data to the host.

12. The method according to claim 9 , further comprising the step of:
storing an identifier associated with the data in the memory as at least a portion of a header associated with the data.

13. The method according to claim 12 , further comprising the step of:
maintaining a map in the host, wherein the map associates the identifier with the initial physical location of the data in the memory.

14. The method according to claim 12 , wherein the identifier is a logical block address, the initial physical location is an address within one of a plurality of read units in the memory that hold the data, and each of the plurality of read units comprises a respective portion of the data and a respective error correction information that protects the respective portion of the data.

15. The method according to claim 14 , wherein the memory has a plurality of pages, the address is in a first page of the plurality of pages that hold the data, the first page includes a first number of the plurality of read units that hold the data, a second page of the plurality of pages includes a second number of the plurality of read units that hold the data, and the first number is different from the second number.

16. The method according to claim 9 , wherein the next unwritten location adjoins previously written data in a physical address space of the memory.

17. An apparatus comprising:
an interface configured to process a plurality of read/write operations to/from a memory; and
a control circuit configured to receive first data from a host, and store second data generated from the first data in the memory, wherein the first data is compressed to generate the second data, the second data has a size that is variable, the second data is stored among a plurality of physical locations in the memory, an initial physical location of the plurality of physical locations that hold the second data is a next unwritten location in the memory, the size of the second data is stored in a first partition of a flash translation layer local to the memory, and the initial physical location of the second data in the memory is stored in a second partition of the flash translation layer in the host.

18. The apparatus according to claim 17 , wherein the interface and the control circuit are part of a solid-state drive controller.

19. The method according to claim 1 , wherein the steps are performed in a solid-state drive controller.

20. The method according to claim 9 , wherein the steps are performed in a solid-state drive controller.

Assignees

• Seagate Technology Llc

Inventors

• Cohen Earl T
• Puri Sumit

Classifications

• G06F2212/7201

  Logical to physical mapping or translation of blocks or pages · CPC title

• G06F12/121

  using replacement algorithms · CPC title

• G06F2212/401

  Compressed data · CPC title

• G06F12/0246 Primary

  in block erasable memory, e.g. flash memory · CPC title

• G06F3/064

  Management of blocks · CPC title