Solid-state hard disk and data access method for use with solid-state hard disk

1. A method for data access on a solid-state drive (SSD), comprising:

caching data-to-be-written to a write cache module of the SSD;

ranking the data-to-be-written in the write cache module based on use frequency of the data-to-be-written;

obtaining group information of the data-to-be-written based on a rewrite interval value of the data-to-be-written, wherein obtaining the group information comprises,

after caching the data-to-be-written, grouping the data-to-be-written based on (i) the rewrite interval value of the data-to-be-written and (ii) dividing valid data pages and invalid data pages into different groups when data pages of a data block in the SSD are unable to be entirely rewritten in synchrony during rewriting, wherein rewriting in synchrony is determined by determining whether a time difference between a time point at which any data page of the data block is rewritten and a time point at which any other data page of the data block is rewritten is shorter than a preset duration,

recording page information of the data-to-be-written, the page information comprising the group information of the data-to-be-written, and

prior to writing the replacement data, determining a target data block in the storage unit based on the group information of the replacement data;

when data storage amount of the write cache module reaches a threshold, determining replacement data from the data-to-be-written based on the ranking of the data-to-be-written; and

writing the replacement data into a storage unit of the SSD based on group information of the replacement data from the group information of the data-to-be-written.

2. The method of claim 1 , wherein:

the data-to-be-written comprises a plurality of data pages;

ranking the data-to-be-written in the write cache module comprises ranking the plurality of data pages based on the respective user frequency of each of the data pages; and

determining the replacement data comprises determining a plurality of replacement data pages from the plurality of data pages based on the ranking of the data pages.

3. The method of claim 1 , wherein the data-to-be written is ranked based on a least recently used page (LRU) algorithm.

4. The method of claim 1 , wherein the replacement data includes infrequently used data-to-be-written according to the ranking.

5. The method of claim 1 , wherein determining the replacement data further comprises determining an amount of the replacement data.

6. The method of claim 1 , wherein the storage unit is a flash memory.

7. The method of claim 1 , further comprising revising group information of the valid data page by increasing a rewrite interval value of the valid data page.

8. A solid-state drive (SSD), comprising:

a write cache module configured to cache data-to-be-written;

a storage unit; and

a control device, comprising:

a ranking unit configured to rank the data-to-be-written in the write cache module based on use frequency of the data-to-be-written;

a grouping unit and a recording unit configured to obtain group information of the data-to-be-written based on a rewrite interval value of the data-to-be-written, wherein

obtaining the group information comprises, after caching the data-to-be-written, grouping the data-to-be-written based on (i) the rewrite interval value of the data-to-be-written and (ii) dividing valid data pages and invalid data pages into different groups when data pages of a data block in the SSD are unable to be entirely rewritten in synchrony during rewriting, wherein rewriting in synchrony is determined by determining whether a time difference between a time point at which any data page of the data block is rewritten and a time point at which any other data page of the data block is rewritten is shorter than a preset duration,

recording page information of the data-to-be-written, the page information comprising the group information of the data-to-be-written, and

prior to writing the replacement data, determining a target data block in the storage unit based on the group information of the replacement data;

a replacing unit configured to, when data storage amount of the write cache module reaches a threshold, determine replacement data from the data-to-be-written based on the ranking of the data-to-be-written; and

a writing unit configured to write the replacement data into the storage unit of the SSD based on group information of the replacement data from the group information of the data-to-be-written.

9. The SSD of claim 8 , wherein:

the data-to-be-written comprises a plurality of data pages;

the ranking unit is further configured to rank the plurality of data pages based on the respective user frequency of each of the data pages; and

the replacing unit is further configured to determine a plurality of replacement data pages from the plurality of data pages based on the ranking of the data pages.

10. The SSD of claim 8 , wherein the data-to-be written is ranked based on a least recently used page (LRU) algorithm.

11. The SSD of claim 8 , wherein the replacement data includes infrequently used data-to-be-written according to the ranking.

12. The SSD of claim 8 , wherein the replacing unit is further configured to determine an amount of the replacement data.

13. The SSD of claim 8 , wherein the storage unit is a flash memory.

14. The SSD of claim 8 , further comprising a revising unit configured to revise group information of the valid data page by increasing a rewrite interval value of the valid data page.