Storage system and compression method of storing compressed data from storage controller physical address space to logical and physical address space of nonvolatile memory

Patent metadata

Field	Value
Publication number	US-11210214-B2
Application number	US-201916570143-A
Country	US
Kind code	B2
Filing date	Sep 13, 2019
Priority date	Feb 14, 2019
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A storage system including a storage controller for compressing a data from a host and a plurality of nonvolatile memory drives for writing the compressed data. The storage controller provides the host with a first logical address space as a logical storage area and includes a plurality of first physical address spaces corresponding to the first logical address space and manages storage areas of the plurality of nonvolatile memory drives. Each of the plurality of nonvolatile memory drives includes a second physical address space that manages a physical storage area of the nonvolatile memory and a second logical address space that corresponds to the second physical address space and to each of the plurality of first physical address spaces. The second logical address spaces and the first logical address space are managed with a common size and a common management size, and leading addresses are aligned with the management size.

First claim

What is claimed is:

1. A storage system comprising:
a storage controller connected to a host;
and a plurality of nonvolatile memory drives connected to the storage controller, wherein the storage controller i) compresses a data from the host, ii) provides the host with a first logical address space as a logical storage area, iii) manages a before-compression data to be stored in the first logical address space, and iv) manages an after-compression data to be written to a plurality of first physical address spaces that correspond to the first logical address space and the plurality of physical address spaces that respectively manage storage areas of the plurality of nonvolatile memory drives,
wherein each of the plurality of nonvolatile memory drives i) includes nonvolatile memory, ii) includes a second physical address space that manages a physical storage area of the nonvolatile memory and a second logical address space that corresponds to the second physical address space and the second logical address space corresponds to each of the plurality of first physical address spaces, iii) manages the after-compression data to be stored in the second logical address space, and iv) writes the after-compression data to the second physical address space,
wherein one of the plurality of second logical address spaces and one of the plurality of first physical address spaces are managed with a common size and a common management size, and the first logical address space and the plurality of first physical address spaces are managed with the common size and the common management size,
and wherein, in the first logical address space, the plurality of first physical address spaces, and the plurality of second logical address spaces, leading addresses are aligned with the common management size.

2. The storage system according to claim 1 , wherein each of the plurality of nonvolatile memory drives has an expansion function for expanding the second physical address space so as to correspond to one of the plurality of first physical address spaces with the common size.

3. The storage system according to claim 2 , wherein the storage controller has after-compression data size information for managing an after-compression data size for each management size.

4. The storage system according to claim 2 , wherein each of the plurality of nonvolatile memory drives has a logical-physical conversion table for managing a correspondence relationship between a logical address, of the second logical address space, provided to the storage controller by each of the plurality of nonvolatile memory drives and a physical address of the nonvolatile memory.

5. The storage system according to claim 2 , wherein the storage controller
stripes a write data according to configuration information when the write data is received from the host,
divides the striped write data into a before-compression management size,
compresses the striped write data, divided into the before-compression management size, to generate respective first after-compression data,
assigns a zero data to a difference between the respective first after-compression data and the before-compression management size,
manages the respective first after-compression data to be stored in respective second logical space of the plurality of second logical address spaces,
and writes the respective first after-compression data to respective second physical space, of the plurality of second physical address spaces, corresponding to the respective second logical space.

6. The storage system according to claim 5 , wherein the storage controller writes, to one of the plurality of second physical address spaces,
a first data obtained by assigning the zero data to the respective first after-compression data,
a second data obtained by reading an old data stored at an address of the first logical address space to which the write data is written and assigning the zero data to the read old data,
a third data obtained by reading a parity data of the old data as an old parity data and assigning the zero data to the old parity data,
and a new parity obtained by generating a parity from the first data, the second data, and the third data, wherein the zero data is removed from the generated parity.

7. A data compression method for a storage system having a storage controller connected to a host and a plurality of nonvolatile memory drives connected to the storage controller,
wherein the storage controller i) compresses a data from the host, ii) provides the host with a first logical address space as a logical storage area, iii) manages a before-compression data to be stored in the first logical address space, and iv) manages an after-compression data to be written to a plurality of first physical address spaces that correspond to the first logical address space and the plurality of physical address spaces that respectively manage storage areas of the plurality of nonvolatile memory drives,
wherein each of the plurality of nonvolatile memory drives i) includes nonvolatile memory, ii) includes a second physical address space that manages a physical storage area of the nonvolatile memory and a second logical address space that corresponds to the second physical address space and the second logical address space corresponds to each of the plurality of first physical address spaces, iii) manages the after-compression data to be stored in the second logical address space, and iv) writes the after-compression data to the second physical address space,
wherein one of the plurality of second logical address spaces and one of the plurality of first physical address spaces are managed with a common size and a common management size, and the first logical address space and the plurality of first physical address spaces are managed with the common size and the common management size,
and wherein, in the first logical address space, the plurality of first physical address spaces, and the plurality of second logical address spaces, leading addresses are aligned with the common management size.

8. The data compression method for a storage system according to claim 7 , wherein each of the plurality of nonvolatile memory drives has an expansion function for expanding the second physical address space so as to correspond to one of the plurality of first physical address spaces with the common size.

9. The data compression method for a storage system according to claim 8 , wherein the storage controller
stripes a write data according to configuration information when the write data is received from the host,
divides the striped write data into a before-compression management size,
compresses the striped write data, divided into the before-compression management size, to generate respective first after-compression data,
assigns a zero data to a difference between the respective first after-compression data and the before-compression management size,
manages the respective first after-compression data to be stored in respective second logical space of the plurality of second logical address spaces,
and writes the respective first after-compression data to respective second physical space of the plurality of second physical address spaces corresponding to the respective second logical space.

10. The data compression method for a storage system according to claim 9 , wherein the storage controller writes, to one of the plurality of second physical address spaces,
a first data obtained by assigning the zero data to the respective first after-compression data,
a second data obtained by reading an old data stored at an address of the first logical address space to which the write data is written and assigning the zero

Assignees

• Hitachi Ltd
• Hitachi Information & Telecommunication Eng Ltd

Inventors

• Ogawa Junji
• Homma Shigeo

Classifications

• G06F2212/7202

  Allocation control and policies · CPC title

• G06F12/0292 Primary

  using tables or multilevel address translation means (G06F12/023 takes precedence; address translation in virtual memory systems G06F12/10) · CPC title

• G06F2212/657

  Virtual address space management · CPC title

• G06F12/0246 Primary

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

• G06F2212/401

  Compressed data · CPC title