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CN-121996157-A - ZNS SSD new writable area generation method and system based on dynamic reorganization of idle physical blocks

CN121996157ACN 121996157 ACN121996157 ACN 121996157ACN-121996157-A

Abstract

The invention relates to the technical field of storage systems, in particular to a ZNS SSD new writable area generating method and system based on dynamic reorganization of idle physical blocks, comprising (1) area state monitoring; the method comprises the steps of (1) triggering decision, (3) selecting idle blocks and target physical addresses, (4) effective data processing, (5) physical reorganization, (6) updating a reorganization area mapping table, (7) metadata persistence, (8) reporting a host, and (9) resource cleaning. The invention obviously improves the space utilization rate and the flexibility.

Inventors

  • XIE PING
  • MENG JIANLIANG

Assignees

  • 青海师范大学

Dates

Publication Date
20260508
Application Date
20251224

Claims (6)

  1. 1. The ZNS SSD new writable area generating method based on the dynamic reorganization of the idle physical blocks is characterized by comprising the following steps: (1) Area status monitoring: On the physical layer, identifying idle physical blocks released by deleting data in the ZNS SSD but distributed in a scattered way on physical addresses by a Zone state monitor; (2) Triggering decision: when the data collected by the regional state monitor meets the recombination trigger condition, the recombination strategy engine is activated, and if the data does not meet the trigger condition, the regional state monitor is in a continuous regional monitoring state; (3) Selecting an idle block and a target physical address: selecting a group of idle physical blocks from the identified idle physical blocks as a reorganization source physical block, and selecting a group of physically continuous blank erasing units as reorganization target areas; (4) And (3) effective data processing: Checking the selected source physical block to judge whether the source physical block contains valid data which is not deleted by the host computer, and if the source physical block does not contain valid data, immediately carrying out physical reorganization; (5) Physical recombination: remapping the selected source physical blocks to the target continuous address interval through arrangement; (6) Updating the reorganization area mapping table: Creating a new logical area entry in the reorganization area mapping table, writing the new logical area entry into the reorganization operation log, and further creating a mapping relation from a Zone LBA starting address visible by a host to a continuous physical address; (7) Metadata persistence: the mapping relation is used as metadata, and atomically written into a safe area of the flash memory; (8) Reporting host: after the persistence is completed, reporting a new logical area with empty state to the host through Report Zones command; (9) And (3) resource cleaning: The source region that is shifted empty is marked as either resettable or offline in its original mapping table.
  2. 2. The method of generating ZNS SSD new writable area based on dynamically reorganizing free physical blocks of claim 1 wherein in step (1) the logic states comprise empty, open, closed, full, and reset.
  3. 3. The method for generating a new writable area of a ZNS SSD based on dynamically reorganizing free physical blocks as set forth in claim 2, wherein in step (2), the reorganizing trigger condition is that the number of free physical blocks is > 300 and the number of available Zones is < 10.
  4. 4. The method of generating ZNS SSD new writable area based on dynamically reorganized free physical blocks of claim 3 wherein in step (4) if valid data exists, the valid data is migrated to an existing and unwritten Zone.
  5. 5. The method for generating a ZNS SSD new writable area based on dynamically reorganizing free physical blocks as recited in claim 4, wherein in step (9), the host releases the logical address resources of the emptied source area through a Reset Zone command, completing the whole resource reclamation and reassignment closed loop.
  6. 6. A ZNS SSD new writable area generating system based on a dynamic reorganization idle physical block is characterized in that the ZNS SSD new writable area generating method based on the dynamic reorganization idle physical block is adopted according to any one of claims 1-5.

Description

ZNS SSD new writable area generation method and system based on dynamic reorganization of idle physical blocks Technical Field The invention relates to the technical field of storage systems, in particular to a ZNS SSD new writable area generation method and system based on dynamic reorganization of idle physical blocks. Background The traditional SSD realizes flexible and easy-to-use general storage through a black box management mechanism by virtue of an FTL flash memory conversion layer. However, when data centers face massive data flooding, the inherent bottlenecks are increasingly highlighted, background garbage collection causes unpredictable performance fluctuations, severe write amplification effects rapidly consume flash life, and a large amount of space reserved for maintaining performance also increases overall ownership costs. To address these challenges, ZNS SSD has evolved, but ZNS divides the storage space into multiple fixed-size regions, the host must write sequentially to each region, and can only free up space by resetting the entire region. This results in the free physical blocks being scattered in the respective areas when part of the blocks in the different areas are invalidated. While to free one area, its valid data must be migrated to the other area, causing additional write operations. Even if there are a large number of scattered free physical blocks, the GC cannot freely integrate any free physical blocks, and the host cannot obtain a new, complete, sequentially writable area unless just the entire area is reset. Disclosure of Invention The invention provides a ZNS SSD new writable area generation method and system based on dynamic reorganization of idle physical blocks, which can overcome certain or certain defects in the prior art. The ZNS SSD new writable area generating method based on the dynamic reorganization idle physical blocks comprises the following steps: (1) Area status monitoring: On the physical layer, identifying idle physical blocks released by deleting data in the ZNS SSD but distributed in a scattered way on physical addresses by a Zone state monitor; (2) Triggering decision: when the data collected by the regional state monitor meets the recombination trigger condition, the recombination strategy engine is activated, and if the data does not meet the trigger condition, the regional state monitor is in a continuous regional monitoring state; (3) Selecting an idle block and a target physical address: selecting a group of idle physical blocks from the identified idle physical blocks as a reorganization source physical block, and selecting a group of physically continuous blank erasing units as reorganization target areas; (4) And (3) effective data processing: Checking the selected source physical block to judge whether the source physical block contains valid data which is not deleted by the host computer, and if the source physical block does not contain valid data, immediately carrying out physical reorganization; (5) Physical recombination: remapping the selected source physical blocks to the target continuous address interval through arrangement; (6) Updating the reorganization area mapping table: Creating a new logical area entry in the reorganization area mapping table, writing the new logical area entry into the reorganization operation log, and further creating a mapping relation from a Zone LBA starting address visible by a host to a continuous physical address; (7) Metadata persistence: the mapping relation is used as metadata, and atomically written into a safe area of the flash memory; (8) Reporting host: After the persistence is completed, reporting a new logical area with empty state to the host through Report Zones command; (9) And (3) resource cleaning: The source region that is shifted empty is marked as either resettable or offline in its original mapping table. Preferably, in step (1), the logic states include empty, open, closed, full, and reset. Preferably, in step (2), the reorganization trigger condition is that the number of idle physical blocks is > 300 and the number of available Zone is < 10. Preferably, in the step (4), if valid data exists, the valid data is migrated to an existing and unfilled Zone. Preferably, in step (9), the host releases the logical address resource of the source area that is emptied through a Reset Zone command, and completes the closed loop of the whole resource recovery and reassignment. The invention provides a ZNS SSD new writable area generating system based on a dynamic reorganization idle physical block, which adopts the ZNS SSD new writable area generating method based on the dynamic reorganization idle physical block. The beneficial effects of the invention are as follows: (1) The space utilization rate and flexibility are remarkably improved, the space fragments are easily caused by the management mode of the traditional ZNS fixed region, and the variable data size is difficult to adapt. The inventio