System and method of direct write and mapping of data in a non-volatile memory having multiple sub-drives
A system and method is disclosed for managing data in a non-volatile memory. The system may include a non-volatile memory having multiple non-volatile memory sub-drives. A controller of the memory system is configured to route incoming host data to a desired sub-drive, keep data within the same sub-drive as its source during a garbage collection operation, and re-map data between sub-drives, separate from any garbage collection operation, when a sub-drive overflows its designated amount logical address space. The method may include initial data sorting of host writes into sub-drives based on any number of hot/cold sorting functions. In one implementation, the initial host write data sorting may be based on a host list of recently written blocks for each sub-drive and a second write to a logical address encompassed by the list may trigger routing the host write to a hotter sub-drive than the current sub-drive.
1. A storage system, comprising:
storage memory having sub-drives, the sub-drives comprising a first sub-drive and a second sub-drive;
one or more controllers configured to cause:
providing an identification of one or more recently written superblocks for the first sub-drive;
receiving a first data from a host write; and
when the host write invalidates a logical block address associated with the one or more recently written superblocks for the first sub-drive:
writing the first data into the second sub-drive that is next hotter than the first sub-drive; and
refraining from writing the first data into an open block in the first sub-drive.
2. The storage system of claim 1 , wherein the one or more controllers are configured to cause:
when the host write does not invalidate the logical block address associated with the one or more recently written superblocks for the first sub-drive, writing the first data into the open block in the first sub-drive,
wherein the first sub-drive includes a block corresponding to the logical block address.
3. The storage system of claim 2 ,
wherein providing the identification of the one or more recently written superblocks for the first sub-drive comprises providing the identification for only a predetermined number of the one or more recently written superblocks for the first sub-drive, and
wherein the one or more controllers are configured to cause:
updating the identification of the one or more recently written superblocks for the first sub-drive when the first data is written into the open block of the first sub-drive; and
when a quantity of the one or more recently written superblocks exceeds the predetermined number, removing an identification of an oldest recently written superblock for the first sub-drive from the identification of the one or more recently written superblocks for the first sub-drive.
4. The storage system of claim 1 , wherein the one or more controllers are configured to cause:
moving data previously stored in the first sub-drive into a different sub-drive of the storage memory by re-mapping at least a portion of the data previously stored in the first sub-drive, without rewriting the at least a portion of the data previously stored in the first sub-drive, into a different physical location of the storage memory.
5. The storage system of claim 4 , wherein moving the data previously stored in the first sub-drive comprises moving the data previously stored in the first sub-drive into the different sub-drive of the storage memory, independently of any garbage collection operation in the first sub-drive.
6. The storage system of claim 4 , wherein:
the at least a portion of the data previously stored in the first sub-drive comprises a superblock of the first sub-drive;
the different sub-drive comprises a next colder sub-drive of the sub-drives, wherein the next colder sub-drive comprises a sub-drive associated with data having a data temperature less than a data temperature of data associated with the first sub-drive; and
re-mapping the at least a portion of the data previously stored in the first sub-drive comprises selecting a coldest superblock of the first sub-drive and re-mapping the coldest superblock to the different sub-drive.
7. The storage system of claim 4 , wherein:
the at least a portion of the data previously stored in the first sub-drive comprises a superblock of the first sub-drive;
the different sub-drive comprises a next hotter sub-drive of the sub-drives, wherein the next hotter sub-drive comprises a sub-drive associated with data having a data temperature greater than a data temperature of data associated with the first sub-drive; and
re-mapping the at least a portion of the data previously stored in the first sub-drive comprises selecting a hottest superblock of the first sub-drive and re-mapping the hottest superblock to the different sub-drive.
8. The storage system of claim 1 , comprising:
an open block group, comprising superblocks assignable to any of the sub-drives for data storage,
wherein the one or more controllers are configured to cause:
initiating a garbage collection operation in one of the sub-drives in response to detecting that an amount of the superblocks in the open block group is below a predetermined minimum threshold; and
selecting a source superblock for the garbage collection operation from a sub-drive having an amount of overprovisioning that is greater than a target overprovisioning for the sub-drive.
9. The storage system of claim 1 , wherein the one or more controllers are configured to cause: when valid data is relocated during a garbage collection operation, relocating the valid data only within a same sub-drive of the storage memory.
10. The storage system of claim 1 , wherein the one or more controllers are configured to cause:
re-mapping at least a portion of data stored in the first sub-drive when an amount of valid data in the first sub-drive exceeds a predetermined amount of logical address space assigned to the first sub-drive.
11. A method for a storage system, the method comprising:
providing an identification of one or more recently written superblocks for a first sub-drive of storage memory;
receiving a first data from a host write; and
when the host write invalidates a logical block address associated with the one or more recently written superblocks for the first sub-drive:
writing the first data into a second sub-drive that is next hotter than the first sub-drive; and
refraining from writing the first data into an open block in the first sub-drive.
12. The method of claim 11 , comprising:
when the host write does not invalidate the logical block address associated with the one or more recently written superblocks for the first sub-drive, writing the first data into the open block in the first sub-drive,
wherein the first sub-drive includes a block corresponding to the logical block address.
13. The method of claim 11 , comprising:
moving data previously stored in the first sub-drive into a different sub-drive of the storage memory by re-mapping at least a portion of the data previously stored in the first sub-drive, without rewriting the at least a portion of the data previously stored in the first sub-drive, into a different physical location of the storage memory.
14. The method of claim 13 , wherein moving the data previously stored in the first sub-drive comprises moving the data previously stored in the first sub-drive into the different sub-drive of the storage memory, independently of any garbage collection operation in the first sub-drive.
15. The method of claim 11 , wherein:
the storage memory comprises an open block group, the open block group comprising superblocks assignable to any of sub-drives of the storage memory; and
the method comprises:
initiating a garbage collection operation in one of the sub-drives in response to detecting that an amount of the superblocks in the open block group is below a predetermined minimum threshold; and
selecting a source superblock for the garbage collection operation from a sub-drive of the storage memory having an amount of overprovisioning that is greater than a target overprovisioning for the sub-drive.
16. The method of claim 11 , comprising:
when valid data is relocated during a garbage collection operation, relocating the valid data only within a same sub-drive of the storage memory.
17. The method of claim 11 , comprising:
re-mapping at least a portion of data stored in the first sub-drive when an amount of valid data in the first sub-drive exceeds a predetermined amount of logical address space assigned to the first sub-drive.
18. An apparatus, comprising:
means for providing an identification of one or more recently written superblocks for a first sub-drive of storage memory;
means for receiving a first data from a host write; and
when the host write invalidates a logical block address associated with the one or more recently written superblocks for the first sub-drive:
means for writing the first data into a second sub-drive that is next hotter than the first sub-drive; and
means for refraining from writing the first data into an open block in the first sub-drive.
19. The apparatus of claim 18 , comprising:
when the host write does not invalidate the logical block address associated with the one or more recently written superblocks for the first sub-drive, means for writing the first data into the open block in the first sub-drive,
wherein the first sub-drive includes a block corresponding to the logical block address.
20. The apparatus of claim 18 , comprising:
means for moving data previously stored in the first sub-drive into a different sub-drive of the storage memory,
wherein the means for moving comprises means for re-mapping at least a portion of the data previously stored in the first sub-drive, without rewriting the at least a portion of the data previously stored in the first sub-drive, into a different physical location of the storage memory.