Data storage device having multiple solid state drives for data duplication, and data processing system including the same
A data storage device includes a plurality of solid state disks (SSDs) and a controller configured to control the SSDs. The controller respectively writes a first data segment and duplicated data of the first data segment to first-type memories of two respective SSDs among the plurality of SSDs in response to a first write request of a host, respectively writes a second data segment and duplicated data of the second data segment to first-type memories of two respective SSDs among the plurality of SSDs in response to a second write request of the host, and writes parity data generated based on the duplicated data to a first-type memory or a second-type memory of a parity SSD. The data storage device may be included in a data processing system.
1. A data processing system comprising:
a host; and
a data storage device connected to the host, the data storage device comprising:
first through N-th solid state disks (SSDs), where N is an integer of at least 2, wherein each of the first through N-th SSDs include a first-type memory and a second-type memory different from the first-type memory, wherein an access time for accessing the first-type memory is faster than an access time for accessing the second-type memory, and
a controller configured to control the first through N-th SSDs,
wherein the controller is configured to store each of data segments corresponding to a plurality of write requests received from the host in the first-type memory of a corresponding one of the first through (N−1)-th SSDs, to store duplicated data based on at least some of the data segments in the first-type memory of the N-th SSD, and to store parity data based on all of the data segments in either of the first-type memory and the second-type memory of the N-th SSD,
wherein the controller is configured to write a first data segment to the first SSD and the same data as the first data segment to the N-th SSD in response to a first write request, and to write a second data segment to the second SSD and the same data as the second data segment to the N-th SSD in response to a second write request, and
wherein the N-th SSD is configured to generate the parity data using first through (N−1)-th data segments stored in the first-type memory of the N-th SSD in response to a parity generation and store command received from the controller, to store the parity data in its second-type memory, and to delete the first through (N−1)-th data segments from its first-type memory.
2. The data processing system of claim 1 , wherein the duplicated data is first partial parity data calculated using a first data segment and a second data segment.
3. The data processing system of claim 2 , wherein the N-th SSD is configured to store the first data segment in its first-type memory, to generate the first partial parity data using the second data segment received from the controller and the first data segment stored in its first-type memory, to store the first partial parity data in its first-type memory, and then to delete the first data segment from its first-type memory.
4. The data processing system of claim 1 , wherein the N-th SSD is configured to receive from the controller the duplicated data generated based on a first data segment and a second data segment, and to store the duplicated data in its first-type memory.
5. The data processing system of claim 1 , wherein the first-type memory of each of the SSDs is non-volatile random access memory (NVRAM) and second-type memory of each of the SSDs is NAND flash memory.
6. A method of operating a data storage device which includes a controller, a buffer, and a plurality of solid state disks (SSDs), the method comprising:
receiving a first write request from a host;
writing a first data segment to the buffer in response to the first write request;
writing the first data segment to a first SSD among the plurality of SSDs;
writing the first data segment to an N-th SSD among the plurality of SSDs;
sending a response to the first write request to the host;
receiving a second write request from the host;
writing a second data segment to the buffer in response to the second write request;
writing the second data segment to a second SSD among the plurality of SSDs;
writing duplicated data based on the second data segment to the N-th SSD;
sending a response to the second write request to the host; and
storing parity data based on first through (N−1)-th data segments in the N-th SSD,
wherein storing the parity data in the N-th SSD comprises:
generating the parity data using the first data segment and the second data segment which are stored in first-type memory of the N-th SSD,
storing the parity data in second-type memory of the N-th SSD, and
deleting the first data segment and the second data segment from the first-type memory of the N-th SSD.
7. The method of claim 6 , wherein the duplicated data based on the second data segment is the same as the second data segment.
8. The method of claim 6 , wherein the duplicated data based on the second data segment is first partial parity data calculated using the first data segment and the second data segment.
9. The method of claim 8 , wherein the writing the duplicated data based on the second data segment to the N-th SSD comprises:
receiving the second data segment from the controller;
generating the duplicated data based on the second data segment using the second data segment and the first data segment stored in first-type memory of the N-th SSD;
storing the duplicated data based on the second data segment in the first-type memory of the N-th SSD; and
deleting the first data segment from the first-type memory of the N-th SSD.
10. A data storage device, comprising:
a plurality of solid state drives (SSDs), including at least a first SSD, a second SSD and a parity SSD, wherein each of the SSDs includes at least one first-type memory and at least one second-type memory different from the first-type memory, wherein an access time for accessing the first-type memory is faster than an access time for accessing the second-type memory; and
a controller configured to control operations of the plurality of SSDs,
wherein the controller is configured to write a first data segment to the first-type memory of the first SSD in response to a first write command received from a host, and to write a second data segment to the first-type memory of the second SSD in response to a second write command received from the host, and further in response to the at least one of the first and second write commands received from the host to write data based on the first data segment and the second data segment to the first-type memory of the parity SSD, and subsequently to write parity data generated from at least the first data segment and the second data segment to at least one of the first-type memory and the second-type memory of the parity SSD,
wherein the data based on the first data segment and the second data segment comprises the first data segment and partial parity data for the first data segment and second data segment, and wherein the controller is configured to write the first data segment to the first-type memory of the parity SSD in response to the first write command and to write the partial parity data for the first data segment and second data segment to the first-type memory of the parity SSD in response to the second write command.
11. The data storage device of claim 10 , wherein the first-type memory is a non-volatile random access memory (NVRAM).
12. The data storage device of claim 11 , wherein the second-type memory is a NAND flash memory.
13. The data storage device of claim 10 , wherein the data based on the first data segment and the second data segment comprises the first data segment and the second data segment, and wherein the controller is configured to write the first data segment to the first-type memory of the parity SSD in response to the first write command and to write the second data segment to the first-type memory of the parity SSD in response to the second write command.
14. The data storage device of claim 10 , wherein the data based on the first data segment and the second data segment comprises the first data segment and partial parity data for the first data segment and second data segment, and wherein the controller is configured to write the partial parity data for the first data segment and second data segment to the first-type memory of the parity SSD in response to the second write command.
15. The data storage device of claim 10 , wherein the first data segment and the second data segment belong to a predetermined data group comprising k data segments, where k>2, and wherein the parity data generated from the first data segment and the second data segment comprises parity data generated from all k data segments, and wherein the controller writes the parity data to the at least one of the first-type memory and the second-type memory of the parity SSD after receiving a k-th write command from the host for writing the k-th data segment to the first-type memory of a k-th one of the SSDs.