KR101791855B1 - Storage device and method of reclaiming space of the same - Google Patents

Abstract

A method for re-collecting space in a storage apparatus can be performed in a storage apparatus having a flash memory, controlling the flash memory using a flash conversion layer, and performing an interaction with a host apparatus. A method of reallocating space in a storage device includes the steps of: determining whether a blank space is present in a target page of the flash memory to record main data related to the write request, when receiving a write request from the host device; And recording the valid data and the main data existing in the reuse target block in the target page when the empty space exists in the target page.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a storage device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage system, and more particularly, to a storage apparatus and a method for re-collecting space thereof.

NAND flash memory devices are widely used for miniaturization and large capacity of semiconductor memory devices because of their low power and fast access time.

On the other hand, since the NAND flash memory does not support an "overwrite " operation, updating data in the NAND flash memory device programs the valid data in a log block associated with the data block, FTL) are address-mapped. Since the valid data is distributed over a plurality of blocks, the NAND flash memory merges the valid data (or the valid page on which the valid data is written) to obtain a free block, and performs a space re-collection operation for optimizing the NAND flash memory Garbage collection (GC) operations).

However, the performance and lifetime of the NAND flash memory may be deteriorated due to time delay and additional data transfer due to the space re-collection operation for the NAND flash memory.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of re-collecting space in a storage apparatus capable of improving the performance and life span of a storage apparatus having a flash memory.

It is another object of the present invention to provide a storage apparatus that performs a method of re-collecting space of a storage apparatus.

According to an aspect of the present invention, there is provided a method for re-collecting space in a storage apparatus, the method comprising: providing a flash memory; controlling the flash memory using a flash conversion layer; Determining whether a blank space is present in a target page of the flash memory to record main data related to the write request when receiving a write request from the host device; And recording the valid data and the main data existing in the reuse target block in the target page when the empty space exists in the target page.

According to an embodiment of the present invention, the step of determining whether or not a blank space is present in the target page may include storing the main data into full page data and partial page data based on a page which is a minimum recording unit of the flash memory And < / RTI >

According to an embodiment of the present invention, the step of recording the valid data and the main data in the target page may include: determining whether the valid data exists in a data input / output queue provided in the storage device; Determining whether a first logical block address for the main data is the same as a second logical block address of the valid data when the valid data is in the data input / output queue; And merging the valid data and the main data when the first logical block address and the second logical block address are different from each other.

According to another embodiment of the present invention, the step of writing the valid data and the main data in the target page may further include invalidating the valid data if the first logical block address is identical to the second logical block address .

According to another aspect of the present invention, there is provided a storage apparatus including a flash memory, the storage apparatus including a flash memory for storing main data related to the write request, Determining whether a blank space exists in a target page of the memory, and if the empty space exists in the target page, the valid data and the main data existing in the target block to be reused may be recorded in the target page.

According to one embodiment, the storage device comprises: a cache buffer; Data input / output queue; A first module for providing the main data to the cache buffer in response to the write request; A second module for providing the valid data to the data input / output queue; And a third module for merging the main data stored in the cache buffer and the valid data output from the data input / output queue.

According to one embodiment, the third module divides the main data into full page data and partial page data based on a page which is a minimum recording unit of the flash memory, and when the main data is partial page data, It can be determined that the empty space exists in the target page.

According to one embodiment, the third module determines whether the valid data exists in the data input / output queue, and when the valid data is in the data input / output queue, the first logical block address for the main data is The valid data and the main data may be merged if the first logical block address is different from the second logical block address.

According to an embodiment, when the first logical block address and the second logical block address are the same, the third module may invalidate the valid data.

A method for reallocating space in a storage apparatus according to embodiments of the present invention includes the steps of: when a storage apparatus receives a write request from a host apparatus, (Or valid data existing in the reuse target block) is merged (or piggybacked) in the main data and recorded on the target page. Therefore, the method of reallocating space in the storage apparatus minimizes the copyback operation in the flash memory (that is, the operation of copying the valid data from the target block to the unused block) It is possible to prevent the performance degradation and the life span shortening.

Also, the method for re-collecting space of a storage apparatus may include determining whether a logical block address between the main data and the valid data is duplicated, invalidating the valid data when the logical block address is duplicated, Can be prevented.

Furthermore, since the storage apparatus according to embodiments of the present invention includes a data input / output queue, it is possible to efficiently perform the space re-collection method of the storage apparatus.

However, the effects of the present invention are not limited to the above effects, and may be variously extended without departing from the spirit and scope of the present invention.

1 is a block diagram illustrating a storage system in accordance with embodiments of the present invention.
FIG. 2 is a diagram showing a comparative example in which the space reattachment of the storage device performed in the storage system of FIG. 1 is almost similar; FIG.
FIG. 3 is a diagram showing an example of a spatial rewinding of a storage apparatus performed in the storage system of FIG. 1; FIG.
4 is a block diagram showing an example of a storage apparatus included in the storage system of FIG.
5 is a flowchart illustrating a method for collecting space in a storage apparatus according to embodiments of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same or similar reference numerals are used for the same components in the drawings.

1 is a block diagram illustrating a storage system in accordance with embodiments of the present invention.

Referring to FIG. 1, a storage system 100 may include a host device 110 and a storage device 140.

The host device 110 can generate a read command or a write command for data on a block-by-block basis on a logical address based on a logical block-based interface using a file system (not shown) . Here, the file system may be an extended file system (Ext4), an NT file system (NTFS), or the like. The host device 110 may also interact with the storage device 120 via the interface protocol (e.g., ATA, PCI, etc.) Transmission (or communication) can be performed.

In addition to the file system, the host device 110 may further include a host controller (not shown), other hardware or software components. For example, the host device 110 may include a host flash translation layer (not shown), and a host Flash translation layer may be used to enable the flash translation layer (e.g., the flash translation layer included in the storage device 120) Some functions can be performed. In this case, the host apparatus 110 more accurately grasps the internal operation information of the storage apparatus 120 through the interaction between the file system and the host controller, and performs operations (for example, Collection operations, and the like) can be efficiently supported.

The storage device 120 may correspond to a NAND flash memory device and may be a solid state drive (SSD), a secure digital card (SDCARD), a universal flash storage (UFS) An embedded multimedia card (EMMC), a compact flash card (CF), a memory stick, an XD picture card, and the like. However, this is merely an example, and the type of the storage apparatus 120 is not limited thereto.

The storage device 120 may include a flash memory 122 and a storage controller (not shown) for controlling the flash memory 122. In FIG. 1, the storage device 120 is shown as including one flash memory 122, but the storage device 120 is not limited thereto. For example, the storage device 120 may include n (where n is an integer equal to or greater than 1) flash memories that perform interactions with each other.

The storage device 120 (or the storage controller) may use an address mapping to convert a logical address to a physical address using a flash translation layer for supporting the file system 111 (address mapping) operation. For example, the storage apparatus 120 may perform an address mapping operation (not shown) for converting a logical address generated in the host apparatus 110 (or a file system) into a physical address of the flash memory 122 using a mapping table Can be performed.

In addition, the storage device 120 (or the storage controller) may perform a read operation, a write operation, an erase operation, a compaction operation, and the like for the flash memory 122 through an address mapping operation. Operation, wear-leveling operation, and the like. Here, the storage device 120 may move the valid pages through a compaction operation to secure a free block of the flash memory 1220, or may optimize the flash memory 122, and the storage device 120 may perform wear leveling The wear of the cells of the flash memory 122 can be leveled by the operation. Meanwhile, since the storage device 120 does not support overwrite and random access, the storage device 120 may have an erase before write restriction.

In embodiments, the storage device 120 may perform a space reclamation operation. Here, the space re-collection operation may correspond to a garbage collection operation. For example, the space re-collection operation may include a compaction operation, a ware leveling operation, and a read reclaim operation to reduce bit errors in the flash memory 122, (Or unused blocks) by moving / merging the valid data distributed on the flash memory 122 by performing the space re-collection operation, thereby optimizing the flash memory 122. [

In embodiments, the storage device 120 may include a cache buffer 121 and a data input / output queue 123.

The cache buffer 121 (or the buffer cache) may temporarily store (or cache) data when performing a read operation, a write operation, or the like to the flash memory 122. [ That is, the cache buffer 121 is an auxiliary memory device for storing data (for example, main data related to a write request), thereby improving the input / output efficiency of the flash memory 122. [

The data input / output queue 121 may be a temporary storage space for storing valid data for space re-collection of the flash memory 122. [ Here, the valid data may be data existing in a block (or a page of a block) selected as a re-collection target block. The data I / O queue 126 should be interpreted to include all data structures (e.g., link lists, priority queues, etc.) that serve as temporary storage spaces.

For reference, in order to reuse the space in the flash memory 122, valid data (that is, valid data existing in the block to be re-collected in the flash memory 122) is stored in the unused block (or unprogrammed The overall performance of the flash memory 122 is deteriorated and the overall performance of the flash memory 122 is degraded when the data is written to the flash memory 122 (i.e., when performing a copyback operation on the valid data in the flash memory 122) The life span can be shortened.

Meanwhile, the storage system 100 according to the embodiments of the present invention uses the data input / output queue 123 and the unused space (empty space of the target page for recording the main data related to the write request) It is possible to minimize the copyback operation on the valid data in the storage area 122. Accordingly, the storage system 100 can prevent (or supplement, mitigate) performance degradation and shortening the life span of the flash memory 122.

In one embodiment, when receiving a write request from the host device 110, the storage device 120 determines whether the main data associated with the write request is a target page (for example, It is possible to determine whether or not a blank space occurs in the recording target page of the recording medium. Here, the write request may be a synchronous write request.

For reference, a write request may include a first write request M1, a second write request M2, and a third write request M3, as shown in FIG. In response to the first write request M1 (or write through), the storage device 120 may write the main data synchronously to the flash memory 122 and respond to the host device 110. [ Also, in response to the second write request M2 (or write-back), the storage device 120 writes the main data only to the cache buffer 121 and, in response to a specific condition (e.g., a specific algorithm) The main data recorded in the cache buffer 121 can be recorded in the flash memory 121. [ Further, in accordance with the third write request M3 (or cache flush), the storage apparatus 120 writes all of the main data recorded in the cache buffer 121 to the flash memory 122, Lt; / RTI >

That is, the storage device 120 may write the main data associated with the request to the flash memory 122 in response to a synchronous write request, such as a first write request M1 and a third write request M3 .

Meanwhile, the host device 110 may generate frequent synchronous write requests to ensure the reliability of the data. In this case, the main data associated with the synchronous write request may be a page of the flash memory 122 (Or a wasted space) may occur in the physical page of the flash memory 122 because the physical page of the flash memory 122 may be smaller than the page (the page that is the minimum recording unit of the physical memory 122). Since the size of the physical page of the flash memory 122 gradually increases with the development of the technology of the flash memory 122, the empty space of the physical page of the flash memory 122, which occurs according to the synchronous write request processing, Can be made larger.

Thus, when the storage device 120 receives a write request (e.g., a synchronous write request) from the host device 110, if the main data associated with the write request is written to the target page, (Or predicts) whether or not it is possible.

For example, the storage device 120 may determine that the main data associated with the write request is partial page data (e.g., data where free space on the page occurs) or full page data (e.g., page Data that is filled in the page and no blank space is generated in the page). For example, the storage device 120 may determine the size of the main data and the size of the page of the flash memory 122 (e.g., the page that is the minimum recording unit of the flash memory 122) If the size of the main data is smaller than the size of the page, the main data can be determined as the partial page data.

In one embodiment, when the main data is partial page data, the storage device 120 writes main data and valid data (that is, valid data stored in the data input / output queue 123) to the target page of the flash memory 122 (Or programmed). That is, the storage apparatus 120 may merge (or piggyback) the valid data corresponding to the empty space of the target page into the main data.

As described above, the storage system 100 according to embodiments of the present invention includes a storage device 120 having a flash memory 122 and a data input / output queue 123, and the storage device 120 is valid The storage device 120 temporarily stores (copies) data (that is, valid data present in the reuse target block selected for space reallocation of the flash memory 122) in the data input / output queue 123, (E.g., a page allocated for recording main data) of the flash memory 122 by merging (or uploading) valid data to the main data associated with the write request when receiving a write request from the flash memory 122 As shown in FIG. That is, the storage system 100 according to the embodiments of the present invention can perform the space re-collection operation of the flash memory 122 using the data input / output queue 123 and the empty space of the target page.

1, the storage device 120 may further include hardware or software components other than the cache buffer 121, the flash memory 122, and the data input / output queue 123. [ For example, the storage device 120 may include a storage controller, wherein the storage controller transfers data on a page-by-page basis using the data input / output queue 123 between the host device 110 and the flash memory 122 Should be construed to include all programs that request / process. For example, a storage controller can be implemented in a program that functions similar to a flash conversion layer or a flash conversion layer.

FIG. 2 is a view showing a comparative example of a space re-arrangement of a storage apparatus performed in the storage system of FIG. 1, and FIG. 3 is a diagram showing an example of a space re-arrangement of a storage apparatus performed in the storage system of FIG.

Referring to FIGS. 1 and 2, the storage system 100 can perform the space re-collection of the flash memory 122 without using the data input / output queue 123. In this case, the storage system 100 allocates an unused block (for example, the fourth block B4) of the flash memory 122 for the space reallocation of the flash memory 122, (For example, the fourth block B4) of the flash memory 122 by copying the valid data recorded in the reclaim target block (for example, the first block B1) , Programming), and erase valid data of the reuse target block. That is, the storage system 100 can re-collect space in the flash memory 122 through a copyback operation on valid data.

For reference, one unused block may be allocated to one reuse target block, and the number of allocated unused blocks may be variously determined according to a required condition (for example, a system parameter).

For example, the flash memory 122 includes blocks B1 to B5, and the first to third blocks B1 to B3 correspond to the used blocks 210 (or the programmed blocks) And the fourth and fifth blocks B4 and B5 may be included in the unused blocks 220. [ On the other hand, the first block B1 may include valid pages (e.g., first and second pages P1 and P2) including data (or valid data).

In this case, the storage system 100 selects the first block B1 as a reuse target block for space re-collection, allocates the fourth block B4 for space re-collection, It is possible to perform a copyback operation on existing valid data. That is, the storage system 100 stores the valid data recorded in the first and second pages P1 and P2 of the first block B1 in the third and fourth pages P3 and B4 of the fourth block B4, P4, respectively. Then, the storage system 100 can erase the valid data existing in the first block B1 so that the first block B1 can be reused as a free block.

As described above, when the storage system 100 does not use the data input / output queue 123, a separate block (for example, the fourth block B4) for space re- A copy back operation may be required.

1 and 3, the storage system 100 according to the embodiments of the present invention includes a data input / output queue 123 and an unused area R2 of a page, Collection can be performed.

When the first valid data VDATA1 and the second valid data VDATA2 exist in the first page P1 and the second page P2 of the first block B1 as the reuse target block, And the first valid data (VDATA1) and the second valid data (VDATA2) to the data input / output queue (123). For example, the storage system 100 may copy (or input) the first valid data VDATA1 and the second valid data VDATA2 to the data input / output queue 123 sequentially.

If the storage system 100 receives a write request and there is free space in the flash memory 122 (e.g., third page P3) where the main data (HDATA) associated with the write request is to be written, (100) can record the valid data in the empty space.

In embodiments, the storage system 100 may determine whether the main data (HDATA) associated with the write request is full page data or partial page data. That is, the storage system 100 judges whether the main data HDATA related to the write request is the full page data or the partial page data, so that the target page (for example, the third page P3 ) Can be judged whether or not an empty space occurs.

For example, the size of the main data HDATA is Q bytes, and the size of the page of the flash memory 122 may be P bytes (where Q is a positive integer and P is a positive integer larger than Q). In this case, the first area R1 of the third page P3 of the sixth block B6, which is the target page, is the use area for recording the main data HDATA, and the second area R1 of the third page P3, The region R2 may be an unused dummy region in which data is not recorded.

In embodiments, the storage system 100 may record the third valid data (VDATA3) output from the data input / output queue 123 in the second area R2. The third valid data VDATA3 is data that is sequentially input and output in the input / output queue 123. For example, the third valid data VDATA3 is a first valid data Data (VDATA1).

That is, when the main data HDATA smaller than the page of the flash memory 122 is recorded in the target page (for example, the first area Rl of the third page P3) Effective data (for example, third effective data VDATA3) for the space re-collection can be recorded in the unused area of the page (for example, the first area R1 of the third page P3).

Accordingly, the storage system 100 minimizes the operation of allocating a separate block (for example, allocating the fourth block B4 for space reallocation in the storage system of FIG. 2), and in this case, The system 100 can prevent the shortening of the life span due to use (or write operation) of the flash memory 122 (e.g., the fourth block B4). The storage system 100 writes the valid data (e.g., the third valid data VDATA3) in the flash memory 122 at the time of the write request processing for the main data HDATA, Lt; RTI ID = 0.0 > VDATA3. ≪ / RTI > Thus, the storage system 100 can improve the speed at which the flash memory 122 resumes near space and the overall speed of the flash memory 122. [

4 is a block diagram showing an example of a storage apparatus included in the storage system of FIG.

Referring to FIGS. 1, 3 and 4, the storage system 100 may include a first module 410, a second module 420, and a third module 430.

The first module 410 provides the main data HDATA to the cache buffer 121 in response to a write request provided from the host device 110 and the cache buffer 121 can temporarily store the main data HDATA have. For example, the first module 410 may be an asynchronous write module.

The second module 420 reads the valid data (for example, the first valid data VDATA1 and the second valid data VDATA2) from the first block B1 as a reuse target block and outputs the valid data to the data input / output queue 123 And the data input / output queue 123 may sequentially output the valid data sequentially input to the data input / output queue 123. For example, the second module 420 may be a valid data pre-fetch module have.

The third module 430 determines whether the main data HDATA is partial page data and outputs main data and valid data (for example, third valid data VDATA3) when the main data is partial page data Can be merged. For example, the third module 430 may be a synchronous write module.

In one embodiment, the third module 430 can divide the main data HDATA into full page data and partial page data based on the page, which is the minimum recording unit of the flash memory 122. 3, when the size of the main data HDATA is smaller than the size of the page (or the reference value set based on the page), the third module 430 divides the main data HDATA into portions It can be judged as page data. On the other hand, when the size of the main data HDATA is larger than the page size (or the reference value set based on the page), the third module 430 determines the main data HDATA as full page data, Only in the flash memory 122 can be recorded.

In one embodiment, the third module 430 may determine whether the data input / output queue 123 has valid data (e.g., third valid data VDATA3). For example, when there is valid data in the data input / output queue 123, the main data HDATA and the valid data are merged. When there is no valid data in the data input / output queue 123, It is determined that space re-collection (for example, a copy-back operation such as a wear leveling operation and a read re-claim operation) is not performed, and only main data can be recorded in the flash memory 122. [

In one embodiment, the third module 430 determines whether the first logical block address for the main data HDATA is the same as the second logical block address of the valid data, If the block address is different, valid data and main data can be merged. The third module 430 may invalidate the third valid data VDATA when the first logical block address and the second logical block address are the same.

When the first logical block address of the main data HDATA and the second logical block address of the third valid data VDATA3 are the same, the main data HDATA is updated with the third valid data VDATA3 . That is, the third valid data VDATA3 is old data, and the main data HDATA is new data. In this case, when the third valid data VDATA3 is written in the flash memory 122 as it is, the value of the first logical block address may be returned to old data instead of new data.

Accordingly, if the first logical block address of the main data HDATA is different from the second logical block address of the third valid data VDATA3, the third module 430 outputs the main data HDATA and the third valid data VDATA3, If the first logical block address of the main data HDATA and the second logical block address of the third valid data VDATA3 are equal to each other, the third valid data VDATA3 is determined to be the old data and invalidation processing Deletion, removal).

In one embodiment, when invalidating the third valid data VDATA3, the third module 430 determines whether there is new valid data in the data input / output queue 123. If there is new valid data, New valid data can be merged into the main data (HDATA).

On the other hand, the third module 430 may write the merged data PDATA (i.e., data obtained by merging the main data HDATA and the third valid data VDATA3) to the flash memory 122. [

As described above, the third module 430 can perform data merge and collision detection of logical block addresses.

As described with reference to FIG. 4, the storage system 100 merges (or upgrades) valid data for space re-collection into the main data HDATA, and the main data HDATA and the valid data- It is possible to prevent the old data from being written to the flash memory 122 by determining whether or not the data is redundant and invalidating the valid data when the logical block address is duplicated.

4, the storage system 100 (or the storage device 120) is shown as including a first module 410, a second module 420, and a third module 430, The storage system 100 may include one module (or storage controller) that performs the functions of the first through third modules 410 through 430. For example,

5 is a flowchart illustrating a method for collecting space in a storage apparatus according to embodiments of the present invention.

Referring to Figures 1 and 5, a method of reallocating space in a storage device may be performed in the storage system 100 (or storage device 120) of Figure 1.

5, when the storage apparatus 120 receives a write request from the host apparatus 110, the method of FIG. 5 is executed in such a manner that the main data HDATA associated with the write request It is determined whether there is a blank space in the target page (S510).

For example, the method of FIG. 5 may be based on a size (or a reference value set based on a page) of the page of the flash memory 122 (e.g., a page that is the minimum recording unit of the flash memory 122) Data HDATA is divided into partial page data or full page data, and when the main data HDATA is partial page data, it can be determined that a blank space exists in the target page.

5, the main data HDATA and the valid data VDATA can be recorded in the target page when there is a vacant space in the target page. Here, the valid data VDATA may be data existing in the reuse target block selected for the space re-collection of the flash memory 122. [ The valid data VDATA may be copied (or input, provided) from the reuse target block to the data input / output queue 123 when the reuse target block for space reallocation of the flash memory 122 is selected.

In the embodiments, the method of FIG. 5 determines whether valid data VDATA is present in the data input / output queue 123 (S520). If valid data VDATA is present in the data input / output queue 123, It is determined whether the first logical block address of the data HDATA is the same as the second logical block address of the valid data VDATA at step S530. If the first logical block address differs from the second logical block address, The data VDATA and the main data HDATA may be merged (S540).

For example, when the valid data VDATA is present in the data input / output queue 123, the method of FIG. 5 performs the merging of the main data HDATA and the valid data VDATA, If there is no data VDATA, it is determined that the space re-collection operation of the flash memory 122 is not performed (or no reuse target block exists), and only the main data HDATA is recorded in the flash memory 122 .

5, if the first logical block address of the main data HDATA is equal to the second logical block address of the valid data VDATA, the valid data VDATA is invalidated (or deleted, removed) (S550).

5, when the first logical block address of the main data HDATA and the second logical block address of the valid data VDATA are the same, the valid data VDATA is the old data of the main data HDATA (Or old data for the first logical block address), and may not write the valid data VDATA to the flash memory 122. [

In one embodiment, the method of FIG. 5 determines whether there is new valid data (VDATA) in the data input / output queue 123 when the valid data (VDATA) has been invalidated. If the new valid data , The new effective data VDATA can be merged into the main data HDATA.

5, the merged data (i.e., data obtained by merging the valid data VDATA with the main data HDATA) can be recorded (or programmed) in the target page (S560).

5, in the case of the space re-collecting method of the storage apparatus according to the embodiments of the present invention, when there is a vacant space in the page to which the main data HDATA is to be recorded, It is determined whether the logical block address is duplicated between the main data HDATA and the valid data VDATA and the valid data VDATA is invalidated when the logical block address is duplicated , It is possible to prevent old data from being written into the flash memory 122. [

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the present invention is not limited to the disclosed exemplary embodiments. It will be appreciated by those skilled in

The method for recovering space in a storage apparatus and a storage apparatus according to embodiments of the present invention can be applied to a storage system having a storage apparatus (i.e., a flash memory apparatus). For example, the present invention can be applied to a storage system having a solid state drive (SSD), an embedded multimedia card (EMMC), a secure digital card (SD card), and the like.

100: storage system 110: host device
120: Storage device 121: Cache buffer
122: flash memory 123: data input / output queue
210: used blocks 220: unused blocks
410: first module 420: second module
430: Third module

Claims (9)

In a storage device having a flash memory, controlling the flash memory using a flash conversion layer, and performing an interaction with the host device,
Determining whether a blank space exists in a target page of the flash memory to record main data related to the write request when receiving a write request from the host device; And
And merging the main data copied from the reuse target block into the data input / output queue and the main data and recording the merged data in the target page when the empty space exists in the target page. The method of claim 1, wherein the step of determining whether a blank space exists in the target page includes:
And dividing the main data into full page data and partial page data based on a page which is a minimum recording unit of the flash memory. 2. The method of claim 1, wherein merging the valid data and the main data and recording the merged data in the target page comprises:
Determining whether the valid data exists in the data input / output queue;
Determining whether a first logical block address for the main data is the same as a second logical block address of the valid data when the valid data is in the data input / output queue; And
And merging the valid data with the main data if the first logical block address and the second logical block address are different from each other. 4. The method of claim 3, wherein merging the valid data and the main data and recording the merged data in the target page comprises:
And invalidating the valid data if the first logical block address and the second logical block address are identical to each other. A flash memory,
The method comprising: determining whether a blank space exists in a target page of the flash memory in which main data related to the write request is to be written, when the write request is received from the host apparatus; And merges the main data copied from the target block into the data input / output queue with the main data and records the merged data in the target page. The storage system according to claim 5,
Cache buffer;
The data input / output queue;
A first module for providing the main data to the cache buffer in response to the write request;
A second module for providing the valid data to the data input / output queue; And
And a third module for merging the main data stored in the cache buffer and the valid data output from the data input / output queue. The method according to claim 6, wherein the third module divides the main data into full page data and partial page data based on a page which is a minimum recording unit of the flash memory, and when the main data is the partial page data, And determines that the empty space exists in the target page. 7. The apparatus of claim 6,
Determining whether the valid data exists in the data input / output queue,
And if the valid data is in the data input / output queue, determining whether a first logical block address for the main data is the same as a second logical block address of the valid data,
And merges the valid data and the main data when the first logical block address is different from the second logical block address. The storage apparatus according to claim 8, wherein the third module invalidates the valid data when the first logical block address and the second logical block address are the same.

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