SSD optimization awareness to atomicity of different system files
Instead of a system with no awareness to the specific properties of the described system files, such as atomicity of different types of system files, utilize the special characteristics of the corresponding system files to optimize storage handling. A host marks a certain logical block address (LBA) range as belonging to an atomic file. That entire range will be treated as a single atomic unit. Conversely, an LBA range being used to append to a log file may have very small atomic units, allowing for incremental updates without changing the atomicity of the rest of the media. When a write command is passed, the write command will have a certain length. Depending on the length of the write command, the device can disassemble the write command into smaller write sectors of the smallest possible write portion. The device will then write the small write portions to a storage location, while keeping an atomic principle of each of the small write portions.
1. A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
define a system logical block address (LBA) range as belonging to an atomic file as defined by a host device;
agree to an atomic chunk size with the host device;
receive aggregated atomic chunks in a single command that belong to the system LBA range;
disassemble the command into a plurality of write commands of the agreed atomic chunk size;
write data for the plurality of write commands to the system LBA range; and
return a status to a host device.
2. The data storage device of claim 1 , wherein the command is a write command and wherein the controller is configured to execute the command.
3. The data storage device of claim 2 , wherein less than all of the command is written.
4. The data storage device of claim 1 , wherein the controller includes an atomic write module.
5. The data storage device of claim 4 , wherein the atomic write module is configured to perform the disassembling.
6. The data storage device of claim 1 , wherein the controller is configured to receive atomic ranges specified by the host device, and wherein the atomic ranges are specified using a nonvolatile memory express (NVMe) dataset management command.
7. A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, wherein the controller is configured to:
receive an assembled write command at a write module, wherein the assembled write command is for an atomic file to a logical block address (LBA) range specified by a host device and treated as a single atomic unit;
disassemble the assembled write command at the write module into a plurality of write commands at an agreed upon atomic chunk size;
pass the disassembled write command to a write module; and
write data of the disassembled write command to the memory device.
8. The data storage device of claim 7 , wherein the assembled write command is a concatenated command.
9. The data storage device of claim 7 , wherein the controller writes the data while keeping an atomic principle of each portion written.
10. The data storage device of claim 9 , wherein the assembled write command is to write a first size and wherein the disassembled write command has an atomicity of a second size that is less than the first size.
11. A data storage device, comprising:
means to store data; and
a controller coupled to the means to store data, wherein the controller is configured to:
receive a plurality of writes commands that are a first size, wherein the plurality of write commands are received as a single write command of a second size that is bigger than the first size, wherein the single write command is for a logical block address (LBA) range belonging to an atomic file as defined by a host device;
disassemble the single write command into the plurality of write commands at an agreed upon atomic chunk size; and
write data associated with the plurality of write commands to the means to store data.