Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller acquires, from a host, write data having the same first size as a data write unit of the nonvolatile memory and obtained by dividing write data associated with one write command having a first identifier indicating a first write destination block in a plurality of write destination blocks into a plurality of write data or combining write data associated with two or more write commands having the first identifier. The controller writes the acquired write data having the first size to the first write destination block by a first write operation.

Abstract: According to one embodiment, a controller constructs a plurality of block groups. The plurality of block groups include at least a first block group configured using a first type block group and a second block group configured using a second block group. The first type block group includes a plurality of non-defective blocks obtained by selecting one or more non-defective blocks in an equal number from each of a plurality of dies or each of a plurality of planes. The second type block group includes a plurality of non-defective blocks. The number of non-defective blocks included in the second type block group is equal to the number of non-defective blocks included in the first type block.

Abstract: A controller manages a plurality of block groups each including one or more blocks among a plurality of blocks provided in a non-volatile memory. The controller assigns one of the plurality of block groups to each of plurality of zones. The controller writes write data which is to be written to a first zone to a shared write buffer and writes write data which is to be written to a second zone to the shared write buffer. When a total size of the write data in the first zone stored in the shared write buffer reaches a capacity of the first zone, the controller copies the write data in the first zone stored in the shared write buffer to the first block group assigned to the first zone.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller receives a first write request associated with first data from a host. In response to a lapse of first time since the reception of the first write request, the controller starts a write process of second data to the nonvolatile memory. The second data includes at least the first data. The controller transmits a first response to the first write request to the host in response to completion of the write process. The first time is time obtained by subtracting second time from third time designated by the host as a time limit of the transmission of the first response since the reception of the first write request.

Abstract: According to one embodiment, in response to receiving a first namespace create command specifying a first attribution from a host, a controller creates a first namespace having the first attribution and a first logical address range. The first logical address range includes logical addresses. The controller sets each of the logical addresses to an unallocated state in which a physical address of the nonvolatile memory is not mapped, during a first period from a time when receiving a power loss advance notification or when detecting an unexpected power loss until a time when the controller becomes a ready state by resupply of a power to the memory system.

Abstract: According to one embodiment, a controller of a memory system writes write data associated with a set of received write requests to a first write destination storage region in a first write mode of writing a plurality of bits per memory cell, without writing the write data to a second storage region. When receiving from a host a first request to cause a state of the first write destination storage region to transition to a second state in which writing is suspended, the controller transfers un-transferred remaining write data from a write buffer of the host to an internal buffer, and writes the remaining write data to the second storage region in a second write mode of writing 1 bit per memory cell.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller manages at least one storage area that is obtained by logically dividing a storage space of the nonvolatile memory. One or more storage areas in the at least one storage area store one or more data pieces, respectively. The controller manages first information on one or more times in which integrity of the one or more data pieces have been confirmed last, respectively.

Abstract: According to one embodiment, a controller of a memory system writes write data associated with a set of received write requests to a first write destination storage region in a first write mode of writing a plurality of bits per memory cell, without writing the write data to a second storage region. When receiving from a host a first request to cause a state of the first write destination storage region to transition to a second state in which writing is suspended, the controller transfers un-transferred remaining write data from a write buffer of the host to an internal buffer, and writes the remaining write data to the second storage region in a second write mode of writing 1 bit per memory cell.

Abstract: According to one embodiment, a memory system manages a plurality of management tables corresponding to a plurality of first blocks in a nonvolatile memory. Each management table includes a plurality of reference counts corresponding to a plurality of data in a corresponding first block. The memory system copies a set of data included in a copy-source block for garbage collection and corresponding respectively to reference counts belonging to a first reference count range to a first copy-destination block, and copies a set of data included in the copy-source block and corresponding respectively to reference counts belonging to a second reference count range having a lower limit higher than an upper limit of the first reference count range to a second copy-destination block.

Abstract: According to one embodiment, a controller of a memory system performs a first operation a plurality of times for each of a plurality of first blocks. The first operation includes a write operation for writing data in a first write mode for writing m-bit data per memory cell and a data erase operation. While a second block is not a defective block, the controller performs a second operation a plurality of times for the second block. The second operation includes a write operation for writing data in a second write mode for writing n-bit data per memory cell and a data erase operation. When the second block is a defective block, the controller selects a first block from the plurality of first blocks, and writes second write data to the selected first block in the second write mode.

Abstract: According to one embodiment, a memory system receives from a host a first write request including a first block identifier designating a first write destination block to which first write data is to be written. The memory system acquires the first write data from a write buffer temporarily holding write data corresponding to each of the write requests, and writes the first write data to a write destination page in the first write destination block. The memory system releases a region in the write buffer, storing data which is made readable from the first write destination block by writ the first write data to the write destination page. The data made readable is a data of a page in the first write destination block preceding the write destination page.

Abstract: According to one embodiment, a memory system receives from a host a first write request including a first block identifier designating a first write destination block to which first write data is to be written. The memory system acquires the first write data from a write buffer temporarily holding write data corresponding to each of the write requests, and writes the first write data to a write destination page in the first write destination block. The memory system releases a region in the write buffer, storing data which is made readable from the first write destination block by writing the first write data to the write destination page. The data made readable is a data of a page in the first write destination block preceding the write destination page.

Abstract: According to one embodiment, a controller of a memory system performs a first operation a plurality of times for each of a plurality of first blocks. The first operation includes a write operation for writing data in a first write mode for writing m-bit data per memory cell and a data erase operation. While a second block is not a defective block, the controller performs a second operation a plurality of times for the second block. The second operation includes a write operation for writing data in a second write mode for writing n-bit data per memory cell and a data erase operation. When the second block is a defective block, the controller selects a first block from the plurality of first blocks, and writes second write data to the selected first block in the second write mode.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller acquires, from a host, write data having the same first size as a data write unit of the nonvolatile memory and obtained by dividing write data associated with one write command having a first identifier indicating a first write destination block in a plurality of write destination blocks into a plurality of write data or combining write data associated with two or more write commands having the first identifier. The controller writes the acquired write data having the first size to the first write destination block by a first write operation.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller acquires, from a host, write data having the same first size as a data write unit of the nonvolatile memory and obtained by dividing write data associated with one write command having a first identifier indicating a first write destination block in a plurality of write destination blocks into a plurality of write data or combining write data associated with two or more write commands having the first identifier. The controller writes the acquired write data having the first size to the first write destination block by a first write operation.

Abstract: According to one embodiment, a memory system manages a plurality of management tables corresponding to a plurality of first blocks in a nonvolatile memory. Each management table includes a plurality of reference counts corresponding to a plurality of data in a corresponding first block. The memory system copies a set of data included in a copy-source block for garbage collection and corresponding respectively to reference counts belonging to a first reference count range to a first copy-destination block, and copies a set of data included in the copy-source block and corresponding respectively to reference counts belonging to a second reference count range having a lower limit higher than an upper limit of the first reference count range to a second copy-destination block.

Abstract: According to one embodiment, a controller of a memory system performs a first operation a plurality of times for each of a plurality of first blocks. The first operation includes a write operation for writing data in a first write mode for writing m-bit data per memory cell and a data erase operation. While a second block is not a defective block, the controller performs a second operation a plurality of times for the second block. The second operation includes a write operation for writing data in a second write mode for writing n-bit data per memory cell and a data erase operation. When the second block is a defective block, the controller selects a first block from the plurality of first blocks, and writes second write data to the selected first block in the second write mode.

Abstract: According to one embodiment, a controller of a memory system writes write data associated with a set of received write requests to a first write destination storage region in a first write mode of writing a plurality of bits per memory cell, without writing the write data to a second storage region. When receiving from a host a first request to cause a state of the first write destination storage region to transition to a second state in which writing is suspended, the controller transfers un-transferred remaining write data from a write buffer of the host to an internal buffer, and writes the remaining write data to the second storage region in a second write mode of writing 1 bit per memory cell.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller acquires, from a host, write data having the same first size as a data write unit of the nonvolatile memory and obtained by dividing write data associated with one write command having a first identifier indicating a first write destination block in a plurality of write destination blocks into a plurality of write data or combining write data associated with two or more write commands having the first identifier. The controller writes the acquired write data having the first size to the first write destination block by a first write operation.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller acquires, from a host, write data having the same first size as a data write unit of the nonvolatile memory and obtained by dividing write data associated with one write command having a first identifier indicating a first write destination block in a plurality of write destination blocks into a plurality of write data or combining write data associated with two or more write commands having the first identifier. The controller writes the acquired write data having the first size to the first write destination block by a first write operation.