Storage system and system garbage collection method

Abstract

A storage system and a system garbage collection method are provided. The storage system includes a first controller, a second controller, and a solid state disk. The first controller or the second controller manages storage space of the solid state disk in a unit of a segment. The first controller is configured to perform system garbage collection on multiple segments of segments managed by the first controller. The second controller is configured to: when the first controller performs system garbage collection, perform system garbage collection on multiple segments of segments managed by the second controller. The multiple segments of the segments managed by the first controller and the multiple segments of the segments managed by the second controller are allocated within a same time period. Therefore, a quantity of times of write amplification in the solid state disk can be reduced.

What is claimed is: 
     
         1 . A storage system, comprising:
 a first controller;   a second controller; and   a solid state disk,   wherein the solid state disk is coupled to the first controller and the second controller, and the solid state disk includes a block, data stored in the block including a first portion and a second portion,   wherein the first portion is associated with a first segment allocated by the first controller, and the second portion is associated with a second segment allocated by the second controller,   wherein the first controller is configured to perform first system garbage collection on the first segment including the first portion, and   wherein the second controller is configured to perform second system garbage collection on the second segment including the second portion, when the first controller is performing the first system garbage collection on the first segment.   
     
     
         2 . The storage system according to  claim 1 , wherein the first controller is further configured to allocate the first segment during a first time period, and wherein the second controller is further configured to allocate the second segment during the first time period. 
     
     
         3 . The storage system according to  claim 1 , wherein the first controller or the second controller manages storage space of the solid state disk in a unit of a segment. 
     
     
         4 . The storage system according to  claim 1 , wherein the block is a minimum erase unit in the solid state disk. 
     
     
         5 . The storage system according to  claim 1 , wherein after the first controller performs the first system garbage collection and the second controller performs the second system garbage collection, the block is labeled as invalid. 
     
     
         6 . The storage system according to  claim 1 , wherein the first controller is configured to instruct the solid state disk to migrate first valid data in the first portion to a first new block, and wherein the second controller is configured to instruct the solid state disk to migrate second valid data in the second portion to a second new block. 
     
     
         7 . A method for collecting system garbage for a storage system, wherein the storage system comprises a first controller, a second controller and a solid state disk, the solid state disk is coupled to the first controller and the second controller, and the solid state disk includes a block, the method comprising:
 performing, by the first controller, first system garbage collection on a first segment, wherein data stored in the block includes a first portion and a second portion, and wherein the first portion is associated with a first segment allocated by the first controller, and the second portion is associated with a second segment allocated by the second controller; and   performing, by the second controller, second system garbage collection on the second segment including the second portion, when the first controller is performing the first system garbage collection on the first segment.   
     
     
         8 . The method according to  claim 7 , further comprising:
 allocating, by the first controller, the first segment during a first time period; and   allocating, by the second controller, the second segment during the first time period.   
     
     
         9 . The method according to  claim 7 , wherein the first controller or the second controller manages storage space of the solid state disk in a unit of a segment. 
     
     
         10 . The method according to  claim 7 , wherein the block is a minimum erase unit in the solid state disk. 
     
     
         11 . The method according to  claim 7 , wherein after the first controller performs the first system garbage collection and the second controller performs the second system garbage collection, the block is labeled as invalid. 
     
     
         12 . The method according to  claim 7 , wherein the performing the first system garbage collection on the first segment comprises instruct the solid state disk to migrate first valid data in the first portion to a first new block; and wherein the performing the second system garbage collection on a second segment comprises instruct the solid state disk to migrate second valid data in the second portion to a second new block.