Storage system and control method thereof
The present disclosure is to optimize processes in a storage system. A storage system includes: a first controller including a first computing device and a first memory; a second controller including a second computing device and a second memory; and an interface circuit that transfers data between the first controller and the second controller. The interface circuit reads first compressed data from the second memory. The interface circuit decompresses the first compressed data to generate first uncompressed data, and writes the first uncompressed data into the first memory.
1. A storage system, comprising:
a first controller including a first computing device, a first interface circuit and a first memory;
a second controller including a second computing device, a second interface circuit and a second memory, the second interface circuit including a compression and decompression computing unit and configured to transfer data between the first controller and the second controller; and
one or more storage drives configured to store data,
wherein the first controller is configured to:
receive a first read request for first uncompressed data from a host; and
send an instruction to the second controller, which has ownership of the first uncompressed data for the first read request, to store the first uncompressed data in the first memory,
wherein the second controller is configured to:
receive the instruction from the first controller;
instruct the one or more storage drives to transfer first compressed data, which is compressed data for the first read request, to the second memory from the one or more storage drives; and
instruct the second interface circuit based on the ownership to:
read the first compressed data from the second memory;
decompress the first compressed data in the second memory with the compression and decompression computing unit to generate the first uncompressed data; and
write the first uncompressed data into the first memory,
wherein the first controller is configured to transfer the first uncompressed data in the first memory to the host.
2. The storage system according to claim 1 , wherein
the first uncompressed data is transferred from the second interface circuit to the first memory via the first interface circuit.
3. The storage system according to claim 1 , wherein
the first compressed data is to be stored in a buffer area of the second memory, and
the first uncompressed data is to be stored in a cache area of the first memory.
4. The storage system according to claim 2 , wherein
the first controller is configured to receive a second read request for second uncompressed data from the host,
the first controller is configured to store second compressed data of the second uncompressed data in the first memory, and
the first interface circuit is configured to:
read the second compressed data from the first memory;
decompress the second compressed data to generate the second uncompressed data; and
write the second uncompressed data into the first memory.
5. The storage system according to claim 2 , wherein
the second controller is configured to, according to the first read request from the first controller, specify a storage address of the first compressed data and a storage address of the first uncompressed data with respect to the second interface circuit, and instruct the second interface circuit to decompress the first compressed data.
6. The storage system according to claim 1 , wherein
the first controller is configured to:
acquire a third read request for third uncompressed data; and
determine the first interface circuit or the second interface circuit as the interface circuit for decompressing third compressed data, which is compressed data for the third read request, based on a load of at least one of the second computing device or the second interface circuit.
7. The storage system according to claim 6 , wherein
the first controller is configured to determine the interface circuit for decompressing the third compressed data based on the loads of both the second computing device and the second interface circuit.
8. A control method for a storage system, the storage system including: a first controller including a first computing device, a first interface circuit and a first memory; a second controller including a second computing device, a second interface circuit and a second memory, the second; interface circuit including a compression and decompression computing unit and configured to transfer data between the first controller and the second controller, and one or more storage drives configured to store data, the control method comprising the steps of:
by the first controller:
receiving a read request from a host; and
sending an instruction to the second controller, which has ownership of data for the read request, to store first uncompressed data, which is uncompressed data for the read request, in the first memory,
by the second controller:
receiving the instruction from the first controller;
instructing the one or more storage drives to transfer first compressed data, which is compressed data for the read request, to the second memory from the one or more storage drives; and
instructing the second interface circuit based on the ownership to:
read the first compressed data from the second memory;
decompress the first compressed data in the second memory with the compression and decompression computing unit to generate the first uncompressed data; and
write the first uncompressed data into the first memory,
wherein the first controller is configured to transfer the first uncompressed data in the first memory to the host.