JP6733214B2 - Control device, storage system, control method, and program - Google Patents

Description

The present invention relates to a control device, a storage system, a control method and a program.

Deduplication functions are being used in storage systems. By using the deduplication function, it is possible to improve the efficiency of the storage area required in the storage system and the communication network band required when writing to the storage system.

Patent Document 1 provides a deduplication function that can be implemented in the actual operation of a storage system, and can reduce the time required to restore the original data from the data after deduplication processing. Is listed.

Further, Patent Document 2 describes an autonomous distributed deduplication file system and the like, in which the degree of duplication of the same data is appropriately controlled, and it is possible to achieve both elimination of excessive duplication and parallel access.

Further, Patent Document 3 describes a storage system capable of improving performance while realizing deduplication of stored data. The storage system described in Patent Document 3 switches the node that mainly executes the deduplication processing according to the value of the importance score. Therefore, the storage system described in Patent Document 3 can reduce the communication load between the accelerator node and the storage node while suppressing the processing load on the accelerator node.

Further, Patent Document 4 describes a storage system and the like. In the technique described in Patent Document 4, a specific management unit that is not sufficiently used for page allocation is released from allocation to a virtual volume. In the technique disclosed in Patent Document 4, the allocated page belonging to the specific management unit is moved to another management unit to write the storage area of the specific management unit to another virtual volume from the host computer. Make it available for access.

Further, Patent Document 5 describes a cache storage program and the like. In the technique described in Patent Document 5, the communication device stores the data in the cache storage area in consideration of the characteristic of data duplication, so that the cache storage area can be efficiently hit.

International Publication No. 2013/051129 JP, 2014-160311, A JP, 2011-175421, A Special table 2012-533099 gazette JP, 2005-201050, A

When reading data from a storage system that uses the deduplication function, all data is read from the storage. Therefore, even in a storage system that uses the deduplication function, a large network band is required when the stored data is read. That is, in the techniques described in the above-mentioned patent documents, no particular consideration is given to the efficiency of processing when data is read.

The present invention has been made in order to solve the above problems, and a main object of the present invention is to provide a storage system or the like that makes data read processing efficient.

A control device according to one aspect of the present invention includes storage control means for controlling a storage device or a storage control device that stores a chunk into which data to be written into a storage device is divided and which is assigned a priority, and is transmitted from the storage device. Determination means for determining whether or not a chunk related to the read target data is stored in the storage means based on the identified information, and the read target data using the chunk stored in the storage means and the storage device based on the determination result. And a read control means for constructing.

A storage system according to an aspect of the present invention includes a control device, a reply unit that transmits identification information identifying a chunk related to read target data to the control device based on a request from the control device, and a chunk related to read target data. And a storage device having read control means for controlling to transmit to the control device a chunk that is not stored in the storage means of the control device.

A control method according to one aspect of the present invention controls a chunk into which data to be written to a storage device is divided to be stored in a storage device or a storage unit with a priority, and identification information transmitted from the storage device. It is determined whether the chunk relating to the read target data is stored in the storage means based on the above, and the read target data is constructed using the chunk stored in the storage means and the storage device based on the determination result.

A program according to an aspect of the present invention includes a process of controlling a computer to store a chunk, into which data to be written to a storage device is divided, into a storage device or a storage device with a priority, and transmission from the storage device. Processing for determining whether a chunk relating to the read target data is stored in the storage means based on the identification information that is stored, and the read target data is stored using the chunk stored in the storage means and the storage device based on the determination result. Execute the process to build.

According to the present invention, it is possible to provide a storage system or the like that improves the efficiency of data read processing.

It is a figure which shows the structure of the control apparatus, the storage apparatus, and the storage system in the 1st Embodiment of this invention. 1 is an example showing a configuration when a storage system according to a first exemplary embodiment of the present invention has a plurality of control devices or storage devices. It is a figure which shows an example of the basic operation|movement of the data write in the storage system in the 1st Embodiment of this invention. It is a figure which shows an example of the basic operation|movement of the data read in the storage system in the 1st Embodiment of this invention. It is a figure which shows an example of a basic operation|movement when backup data is stored in the storage system in the 1st Embodiment of this invention. It is a figure which shows the operation example of the data write in the storage system in the 1st Embodiment of this invention. It is a figure which shows the operation example of the data read in the storage system in the 1st Embodiment of this invention. It is a figure which shows the operation example when backup data is stored in the storage system in the 1st Embodiment of this invention. 6 is a flowchart showing an example of an operation related to writing in the storage system or the like according to the first exemplary embodiment of the present invention. 3 is a flowchart showing an example of an operation related to reading of the storage system and the like according to the first exemplary embodiment of the present invention. It is a figure showing an example of an information processor which realizes a control unit etc. in an embodiment of the present invention.

Embodiments of the present invention will be described with reference to the accompanying drawings. In the embodiment of the present invention, each component of each device such as a control device described later represents a block of a functional unit. Some or all of the components of each device are realized by an arbitrary combination of an information processing device 500 and a program as shown in FIG. 11, for example. The information processing device 500 includes, for example, the following configuration.

-CPU (Central Processing Unit) 501
-ROM (Read Only Memory) 502
RAM (Random Access Memory) 503
-Program 504 loaded in RAM 503
-Storage device 505 that stores the program 504
-Drive device 507 for reading and writing the recording medium 506
-Communication interface 508 connected to the communication network 509
-Input/output interface 510 for inputting/outputting data
.Bus 511 for connecting each component
Each component of each device in each embodiment is realized by the CPU 501 acquiring and executing the program 504 that realizes these functions. The program 504 that realizes the function of each component of each device is stored in the storage device 505 or the RAM 503 in advance, for example, and is read by the CPU 501 as necessary. The program 504 may be supplied to the CPU 501 via the communication network 509, or may be stored in the recording medium 506 in advance and the drive device 507 may read the program and supply it to the CPU 501.

There are various modifications to the method of realizing each device. For example, each device may be realized by an arbitrary combination of an information processing device 500 and a program that are different for each component. Further, a plurality of constituent elements included in each device may be realized by an arbitrary combination of one information processing device 500 and a program.

Further, some or all of the constituent elements of each device are realized by a general-purpose or dedicated circuit including a processor or the like, or a combination thereof. These may be configured by a single chip, or may be configured by a plurality of chips connected via a bus. Some or all of the constituent elements of each device may be realized by a combination of the above-described circuits and the like and a program.

(First embodiment)
Subsequently, the first embodiment of the present invention will be described. FIG. 1 is a diagram showing configurations of a control device, a storage device, and a storage system according to the first embodiment of the present invention. FIG. 2 is an example showing a configuration when the storage system according to the first embodiment of the invention has a plurality of control devices or storage devices. FIG. 3 is a diagram showing an example of a basic operation of writing data in the storage system according to the first embodiment of the present invention. FIG. 4 is a diagram showing an example of a basic operation of reading data in the storage system according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of a basic operation when backup data is stored in the storage system according to the first embodiment of the present invention. FIG. 6 is a diagram showing an operation example of data writing in the storage system according to the first embodiment of the present invention. FIG. 7 is a diagram showing an operation example of reading data in the storage system according to the first embodiment of the present invention. FIG. 8 is a diagram showing an operation example when backup data is stored in the storage system according to the first embodiment of the present invention. FIG. 9 is a flowchart showing an example of a write operation of the storage system etc. according to the first embodiment of this invention. FIG. 10 is a flowchart showing an example of an operation related to reading of the storage system etc. according to the first embodiment of this invention. FIG. 11 is a diagram illustrating an example of an information processing device that realizes the control device and the like according to the embodiment of the present invention.

It is assumed that the storage system in this embodiment has a general deduplication function. That is, when data is stored in the storage, data to be written (hereinafter referred to as “write target data”) is divided into units called chunks. In addition, information for identifying a chunk such as a hash value is required for the chunk. Each chunk may have a predetermined size (that is, a fixed length) or a different size (that is, a variable length). Then, it is determined whether the chunk is already stored in the storage device based on the hash value. As a result of the determination, the data that has not been stored in the storage device is stored in the storage.

First, an outline of the storage system according to the first embodiment of this invention will be described.

The storage system in this embodiment has a general deduplication function. The storage system also includes a server having a control device and a storage device. The control device is provided with a storage unit that can be accessed at a higher speed than a storage device as a local storage unit.

3 and 4 are diagrams respectively showing a data writing or reading process when a storage unit is provided in a control device of a storage system having a general deduplication function. In the example shown in FIG. 3, it is assumed that the storage system includes a server including a control device and a storage device, as in the storage system according to this embodiment.

As described above, when data is written to a storage system having a general deduplication function, write target data is divided into units called chunks. In the example shown in FIG. 3 or 4, the write target data is divided into five chunks from chunk A to chunk E. In the example shown in FIG. 3, it is assumed that three chunks A, C, and D have been stored in the storage device in advance. Also, it is assumed that chunks A and C are stored in advance in a local storage unit. In this case, as an example of the operation, two chunks B and E that have not been stored in the storage device are stored in the local storage unit together with the transfer from the server to the storage device.

When data is read from the storage system in this embodiment, chunks stored in the local storage unit are used. That is, in the control device, the storage device is queried for the hash value of the chunk to be read. Subsequently, the hash value is used to confirm whether the chunk exists in the local storage unit. As a result, when it is confirmed that the chunk to be read is stored in the local storage unit, the chunk is read from the local storage unit.

In the example shown in FIG. 4, it is assumed that the four chunks A, B, C, and E have already been stored in the local storage unit provided in the server. Then, the read target data is composed of five chunks A to E. In this case, the chunks A, B, C and E are read from the local storage unit when the read target data is constructed. The chunk D is transferred from the storage device. That is, in the storage system according to this embodiment, the amount of data transferred from the storage device at the time of reading data is reduced as compared with a storage system having a general deduplication function.

That is, since the control device includes the storage unit, the storage system according to the present embodiment makes the data reading process efficient.

However, the capacity of the storage unit prepared for the server that realizes the control device may be smaller than the storage capacity of the storage device. If there is no free space in the storage unit, the chunk previously stored in the storage unit may be deleted when a new chunk is stored. Then, when deleting the chunks stored in advance in the storage unit, it is considered that there is room for further improvement in the method of determining the chunks to be deleted.

FIG. 5 shows an example of chunks stored in the storage unit prepared for the server when data is repeatedly written to the storage device. In the example shown in FIG. 5, the repeatedly written data becomes backup data. In this example, a so-called full backup is performed at the first writing. That is, all the data to be backed up are written. In the subsequent writing, so-called incremental backup is performed. That is, of the data to be backed up, only the data whose contents have been added or changed is written as backup data. In addition, the storage unit can store six chunks, and if there is no free space, it is assumed that the chunks stored in the earliest period (in other words, the oldest) are deleted in order. In the example shown in FIG. 5, in the first full-up backup, the write target data is divided into, for example, five chunks A to E. The five chunks are stored in the storage unit prepared in the storage device and the control device.

Subsequently, during the incremental backup, for example, a portion corresponding to the chunk D of data in the full backup is updated according to the addition or change of the contents.
At the time of the first incremental backup, the chunk at the location corresponding to chunk D is updated to chunk F. The chunk F is stored in the storage unit prepared in the server. In this case, since there is a vacancy in the storage unit, the chunk F is stored in the storage unit without deleting other chunks.

At the time of the second incremental backup, the chunk at the location corresponding to chunk F is updated to chunk G. The chunk G is stored in the storage unit 140 prepared in the server. However, since there is no free space in the storage unit 140, one of the chunks stored in the storage unit 140 is deleted when the chunk G is stored in the storage unit 140. In the example shown in FIG. 5, chunk A, which is one of the chunks stored in the earliest period, is deleted.

Similarly, in the third and subsequent incremental backups, the chunks at the locations corresponding to the original chunk D are sequentially updated. The updated chunk is stored in the storage unit 140 similarly to the chunk F or G. Then, as the updated chunk is stored, the chunks stored in the storage unit 140 are deleted in the order described above. In the example shown in FIG. 5, the chunks stored in the full backup are sequentially deleted. After the sixth incremental backup is performed, the storage unit stores six chunks F, G, H, I, J, and K.

It is assumed that the backup data is restored after six incremental backups have been performed. FIG. 6 shows an example of a chunk reading procedure when restoration is performed. In the example shown in FIGS. 5 and 6, the backup data is composed of five chunks A, B, C, K and E. Therefore, among the chunks stored in the storage unit, the chunk used for restoration is one of the chunks K. Therefore, the chunks A, B, C, and E are read from the storage device, and the chunk K is read from the storage unit, whereby backup data is constructed.

In the example shown in FIG. 5 or 6, the amount of data transferred from the storage device is reduced by using one of the chunks stored in the storage unit. That is, the data reading process is made efficient. However, among the chunks stored in the storage unit, the chunks F to J are chunks that are not used for restoring the backup data described above. That is, it is considered that the efficiency of the data reading process can be further improved by changing the selection of the chunk deleted from the storage unit. In the example shown in FIG. 5 or 6, if the chunks A, B, C, and E are stored in the storage unit, the backup data can be restored without reading them from the storage device.

Therefore, in the storage system according to the present embodiment, the control device provided in the server or the like includes a storage unit, and further gives priority to each of the chunks stored in the storage unit 1. That is, when there is no free space in the storage unit, chunks with high priority remain in the storage unit, and chunks with low priority are deleted from the storage unit.

Similar to the example shown in FIG. 5, FIG. 7 shows an example of chunks stored in the storage unit prepared for the server when data is repeatedly written to the storage device. Similar to the example shown in FIG. 5, it is assumed that the repeatedly written data is backup data. Further, similarly to the example shown in FIG. 5, it is assumed that full backup is performed in the first writing and incremental backup is performed in the subsequent writing. In addition, the chunk stored in the storage unit 140 at the time of full backup is set with a higher priority than other chunks, and the chunk stored in the storage unit 140 at the time of incremental backup is lower than other chunks. Suppose a priority is set.

In the example shown in FIG. 7, the chunks stored in the storage unit are the same as those in FIG. 5 at the first time of the full backup and the incremental backup. In this case, among the chunks stored in the storage unit, the chunks A, B, C, D, and E are given a higher priority than others, and the chunk F is given a lower priority than others. Is given.

At the second time of the incremental backup, the chunk G is stored in the storage unit. However, since there is no free space in the storage unit, one of the chunks stored in the storage unit is deleted. In this case, the chunk to be deleted is determined according to the priority.

In the example shown in FIG. 7, a low priority is given to the chunk F stored in the first incremental backup, as described above. Therefore, at the time of the second incremental backup, the chunk F is deleted and the chunk G is stored in the storage unit prepared in the server.

Even when writing is performed with the subsequent incremental backup, a low priority is similarly given to the chunk stored during the incremental backup. Therefore, when a chunk is stored in the storage unit, it is deleted and a new chunk is stored.

Also in the example shown in FIG. 7, it is assumed that backup data is restored after six incremental backups have been performed. FIG. 8 shows an example of a chunk reading procedure when the restoration is performed in the example shown in FIG. In the example shown in FIGS. 7 and 8, the backup data is composed of five chunks A, B, C, K and E. All of these chunks are stored in the storage unit. Therefore, the backup data is constructed using only the chunks stored in the storage unit. That is, in the examples shown in FIGS. 7 and 8, the backup data is constructed without transferring the data from the storage device to the server equipped with the control device.

As described above, by giving priority to the chunks stored in the storage unit 140, the storage system according to this embodiment can further improve the efficiency of data read processing.

Next, an outline of the configuration of the storage system according to the first embodiment of this invention will be described.

As shown in FIG. 1, the storage system 10 according to the first exemplary embodiment of the present invention includes a control device 11 and a storage device 12. The control device 11 includes at least a storage control unit 110, a determination unit 120, and a read control unit 130, which are included in a region surrounded by a dashed line in the drawing. The control device 11 also includes a storage unit 140 and a hash table 150. In the present embodiment, it is assumed that the control device 11 further includes a dividing unit 160 and a calculating unit 170, similar to a general server that accesses a storage device having a deduplication function.

The storage control unit 110 controls the chunks relating to the data to be written to the storage device 12 to be given priority and stored in the storage unit 140. The storage control unit 110 also controls the storage device 12 to store a chunk related to data to be written to the storage device 12. In the present embodiment, the chunk indicates a unit of data when the write target data to the storage device 12 is divided into an arbitrary number. Based on the identification information such as the hash value transmitted from the storage device 12, the determination unit 120 stores in the storage unit 140 a chunk related to the data to be read (hereinafter referred to as “read target data”). To judge. The read control unit 130 builds the read target data using the chunks stored in the storage unit 150 and the storage device 12, based on the determination result by the determination unit 120. The storage unit 140 stores the chunks divided by the dividing unit 160. The storage unit 140 may be referred to as a “local storage unit” in the following description. The hash table 150 stores hash values for the chunks stored in the storage unit 140. The dividing unit 160 divides the data to be written in the storage device 12 into an arbitrary number of chunks. The calculator 170 calculates a hash value for each of the chunks generated by the divider 160. In the present embodiment, the hash value is used as identification information that distinguishes each chunk.

The storage device 12 includes a storage unit 210, a hash table 220, a storage unit 230, a reply unit 240, a transfer unit 250, and a duplication determination unit 260. The storage unit 210 stores data divided into chunks. The hash table 220 stores hash values for the chunks stored in the storage unit 210. The duplication determination unit 260 determines, based on the hash value calculated by the calculation unit 170 of the control device 11, whether or not a chunk related to the hash value is stored in the storage unit 210. The storage unit 230 stores the chunk sent from the storage control unit 110 of the control device 11 in the storage unit 210. Based on the request from the control device 11, the reply unit 240 sends the hash value that identifies the chunk related to the read target data to the determination unit 120 of the control device 11. The transfer unit 250 performs control to acquire, from the storage unit 210, a chunk that is not stored in the storage unit 140 of the control device 11 among the chunks related to the read target data, and transmits the chunk to the control device 11.

In this embodiment, the control device 11 is provided in a server or the like that writes and reads data to and from the storage device 12. That is, the control device 100 is realized as a program that operates in a server such as the information processing device 500 shown in FIG. 11. In this case, the server has a configuration such as the information processing apparatus 500 shown in FIG. 8 described above, for example. However, the control device 100 may be realized in other modes.

Further, in this embodiment, the storage system 10 is a storage that backs up data, for example. That is, the server provided with the control device 11 is, for example, a backup server that backs up data. The storage device 12 is, for example, a backup storage. However, the storage system 10 in this embodiment may be used for other purposes such as a file server, for example.

The storage system 10 shown in FIG. 1 has one control device 11 and one storage device 12, respectively. However, the number of control devices 11 or storage devices 12 is not particularly limited. That is, as in the example shown in FIG. 2, the storage system 10 may include the control devices 11-1 to 11-N and the storage devices 12-1 to 12-N. In this case, each of the control devices 11-1 to 11-N may target any of the storage devices 12-1 to 12-N to write or read data.

Next, details of each component of the storage system 10 according to the first embodiment of the present invention will be described. First, details of each component of the control device 11 included in the storage system 10 will be described.

The storage control unit 110 controls to store the chunk in the storage unit 140 or the storage device 12 which is a local storage unit. The storage control unit 110 controls to store, in the storage unit 210, chunks that are determined by the duplication determination unit 260 of the storage device 12 to be unstored in the storage unit 210. This control is similar to the control in a general server that accesses a storage device having a general deduplication function. At the same time, the storage control unit 110 stores the chunk related to the data to be written in the storage device 12 in the storage unit 140. As described above as an outline, the chunk stored in the storage unit 140 is used when the data related to the chunk is set as the read target data.

The data stored in the storage unit 140 by the storage control unit 110 is not particularly limited, and may be any chunk related to the data to be written in the storage device 12. That is, the storage control unit 110 may store, in the storage unit 140, chunks that the duplication determination unit 260 of the storage device 12 has determined to be unstored in the storage unit 210. Alternatively, even if the duplication determination unit 260 determines that the chunk is already stored in the storage unit 210, the storage control unit 110 does not store the chunk if the chunk is not stored in the storage unit 140. May be stored in the storage unit 140.

When the chunk is stored in the storage unit 140, it takes time according to the configuration of the storage unit 140 and the like. However, generally, the time is shorter than the time required when the chunk is stored in the storage unit 210 of the storage device 12. Therefore, the storage control unit 110 stores the chunks that have not been stored in the storage unit 210 in the storage unit 140, so that the time required for storage in the storage unit 140 is substantially hidden.

The storage control unit 110 also manages the chunks stored in the storage unit 140 based on the priority assigned to each chunk.

For example, when the storage control unit 110 stores a chunk, the storage unit 140 may have no free space to store the chunk. In this case, the storage control unit 110 deletes a part of the chunk stored in the storage unit 140 and secures an area for storing a new chunk. The storage control unit 110 determines a chunk to be deleted based on the priority given to each of the chunks stored in the storage unit 140. In this case, the storage control unit 110 does not delete the chunk to which the relatively high priority is given, and leaves it in the storage unit 140, and deletes the chunk to which the relatively low priority is given from the storage unit 140. The storage unit 140 is managed as described above.

The degree of priority given to the chunk by the storage control unit 110 is determined by various methods. As an example, the storage control unit 110 determines the priority level according to the type of write target data that is the source of the chunk stored in the storage unit 140.

As described above, for example, when the write target data is backup data, the storage control unit 110 determines the priority level according to whether it is a chunk for full backup or a chunk for incremental backup. To do. That is, the storage control unit 110 gives a relatively high priority to a chunk related to a full backup and a relatively low priority to a chunk related to an incremental backup. Chunks of data for incremental backups are often less needed in a shorter period of time than chunks of data for full backups. Therefore, when the storage control unit 110 gives such a priority, the efficiency of data read processing can be improved.

The storage control unit 110 assigns a higher priority to a chunk that is expected to be read out than other chunks, based on the type of write target data that is the source of the chunk stored in the storage unit 140. You may.

As another method, the storage control unit 110 may determine the priority level based on the result of the determination by the duplication determination unit 260 of the storage device 12.
In this case, the storage control unit 110 gives a relatively low priority to, for example, a chunk that is determined to be unstored and is newly stored in the storage unit 140. Then, when the chunk determined to be already stored in the storage device 12 by the duplication determination unit 260 is stored in the storage unit 140, the priority of the chunk is updated to be relatively high. When the storage control unit 110 assigns such a priority, it is possible to improve the efficiency of the read process regarding data that may be read.

In this case, the high priority given to each chunk may be opposite to that in the above-described example. For example, the storage control unit 110 may give a relatively low priority to a chunk that is determined to be unstored and is newly stored in the storage unit 140.

The storage control unit 110 may change the priority of the chunk stored in the storage unit 140 according to the time from storage and the like. For example, the storage control unit 110 may update the priority of the chunks stored in the storage unit 140 so that the priority set when writing to the storage unit 140 is decreased every predetermined period or the like. ..

In addition to this, the storage control unit 110 may determine the high priority given to the chunk by combining the methods described above. For example, the storage control unit 110 may change the priority for each chunk and give it, and update the given priority according to the time from storage.

In this example, when the data is backup data, the storage control unit 110 assigns a priority of “8” to a chunk related to full backup and a priority of “1” to a chunk related to incremental backup. It is stored in the storage unit 140. Then, the storage control unit 110 updates the priority given to each chunk so as to be decreased by one per day.

In this example, when the full backup is executed once a week, when the backup data is restored, the chunk related to the latest full backup or the incremental backup is stored in the storage unit 140 with priority. Become. This is because the priority of the chunk for the latest full backup executed immediately before is smaller than the priority of the chunk for the incremental backup for the latest full backup.

Therefore, it becomes possible to restore using the chunk stored in the storage unit 140, and as a result, the data reading process becomes efficient.

It should be noted that the storage control unit 110 is not limited to the case where there is no free space in the storage unit 140, and is stored when the free space in the storage unit 140 satisfies a predetermined condition, such as the free space having a predetermined size. The chunk stored in the unit 140 may be deleted.

Further, when storing the chunk in the storage unit 140, the storage control unit 110 also stores the hash value corresponding to the chunk in the hash table 150. In the present embodiment, the method of calculating the hash value and the format in the storage system 10 are not particularly limited. That is, the hash value may be any information that allows each chunk stored in the storage unit 140 or 210 to be identified.

The determination unit 120 determines whether the chunk related to the read target data is stored in the storage unit 140. The determination unit 120 determines whether the chunk is stored in the storage unit 140 based on the hash value transmitted from the storage device 12.

The determination unit 120 inquires of the storage device 12 about the hash value regarding the read target data. In this case, the reply unit 240 included in the storage device 12 returns the hash value for each of the chunks forming the read target data to the determination unit 120. Whether the chunk is stored in the storage unit 140 by comparing the hash value returned from the reply unit 240 with each of the hash values stored in the hash table 150 included in the control device 11 by the determination unit 120. To judge. That is, the determination unit 120 stores the chunk associated with the hash value in the storage unit 140 when any of the hash values stored in the hash table 150 matches the hash value returned from the reply unit 240. It is determined that

The read control unit 130 builds the read target data based on the determination result by the determination unit 120. The read control unit 130 reads the chunk from the storage unit 140 when the determination unit 120 determines that the chunk related to the read target data exists in the storage unit 140. When it is determined that the chunk related to the data to be read does not exist in the storage unit 140, the read control unit 130 acquires the chunk via the transfer unit 250 of the storage device 12.

The read control unit 130 constructs the read target data when all the chunks related to the read target data are acquired. The constructed read target data is appropriately transmitted to the request source of the data or the like.

In this way, the read control unit 130 uses the chunks stored in the storage unit 140 when constructing the read target data, so that the amount of data transferred from the storage device 12 to the control device 11 is reduced.

The storage unit 140 stores the chunks divided by the dividing unit 160. As described above, the chunk stored in the storage unit 140 is used when reading data from the storage system 10.

It is preferable that the storage unit 140 can be accessed at high speed by each component of the control device 11 as compared with the storage device 12. As an example, it is preferable that the storage unit 140 be realized by using a storage device built in a server that realizes the control device 11. As a storage device incorporated in the server, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like is used. The storage unit 140 may be connected to the control device 11 via a communication network. For example, the storage unit 140 may be a storage device such as a NAS (Network Attached Storage) connected via a communication network having a wider band than the storage device 12. In this case, it is preferable that the storage unit 140 has a higher transfer rate and a wider band in the communication network that connects the control device 11 to each other, as compared with the communication network that connects the control device 11 and the storage device 12.

The capacity of the storage unit 140 may be smaller than that of the storage unit 210 of the storage device 12. That is, the storage unit 140 may be configured to store a part of the chunk stored in the storage device 12.

The hash table 150 stores hash values for the chunks stored in the storage unit 140. In the present embodiment, for example, a part of the storage unit 140 is used as the hash table 150.

The division unit 160 and the calculation unit 170 are elements generally included in a storage system having a deduplication function. That is, the dividing unit 160 divides the write target data to the storage device 12 into an arbitrary number of chunks. As described above, the dividing unit 160 may divide the chunks into the same size, or may divide the chunks into different sizes.

Further, the calculation unit 170 calculates a hash value for each of the chunks generated by the division unit 160. The calculation unit 170 transmits the calculated hash value to the storage device 12, and inquires whether the chunk corresponding to the hash value has been stored in the storage device 12. In the storage device 12, it is determined whether the chunk corresponding to the hash value has been stored in the storage device 12 based on the hash value.

Next, details of each component of the storage device 12 included in the storage system 10 will be described.

The storage unit 210, as the storage device 12, stores the data divided into chunks. The storage unit 210 is realized using a non-volatile storage device such as an HDD or SSD. Further, the storage unit 210 may have a configuration of RAID (Redundant Arrays of Inexpensive Disks).

The hash table 220 stores hash values for each of the chunks stored in the storage unit 210.

The duplication determination unit 260 determines whether a chunk is stored in the storage unit 210. The duplication determination unit 260, similar to a storage system having a general deduplication function, stores a chunk corresponding to the hash value in the storage unit 210 based on the hash value calculated by the calculation unit 170 of the control device 11. Determine whether it is stored. That is, the duplication determination unit 260 acquires the hash value calculated by the calculation unit 170 of the control device 11 and compares the hash value with each of the hash values stored in the hash table 220. Then, if the hash value matches any of the hash values stored in the hash table 220, the duplication determination unit 260 determines that the chunk corresponding to the hash value is stored in the storage unit 210. When the hash value matches the hash value stored in the hash table 220, the duplication determination unit 260 determines that the chunk corresponding to the hash value is not stored in the storage unit 210.

The storage unit 230 stores the chunk transmitted from the storage control unit 110 of the control device 11 in the storage unit 210. The storage unit 230 acquires the hash value corresponding to the chunk together with the chunk, and stores the hash value in the hash table 220.

The reply unit 240 transmits the hash value for the chunk regarding the read target data to the determination unit 120 of the control device 11 based on the inquiry from the determination unit 120 of the control device 11. The determination unit 120 uses the hash value acquired from the reply unit 240 to determine whether a chunk for the hash value is stored in the storage unit 140.

The transfer unit 250 controls to acquire the chunk related to the read target data from the storage unit 210 and transmit the chunk to the control device 11. The read control unit 130 of the control device 11 acquires the chunk from the storage device 12 when the chunk related to the read target data does not exist in the storage unit 140. That is, the transfer unit 250 controls the chunks that are not stored in the storage unit 140 of the control device 11 to be transmitted to the control device 11.

Next, with reference to the flowcharts shown in FIGS. 9 and 10, details of the operation of the storage system 10 or each component thereof in the first embodiment of the present invention will be described.

First, with reference to the flowchart shown in FIG. 9, details of the write operation of the control device 11 mainly of the storage system 10 according to the first embodiment of the present invention will be described.

First, the division unit 160 of the control device 11 divides the write target data into chunks (step S101). Next, the calculation unit 170 calculates a hash value for the chunk obtained in step S101 (step S102).

Next, the calculation unit 170 transmits the hash value obtained in step S102 to the storage device 12, and inquires whether the chunk corresponding to the hash value has been stored in the storage device 12 (step S103). In the storage device 12, the duplication determination unit 260 determines whether the chunk corresponding to the hash value has already been stored in the storage device 12.

When the duplication determination unit 260 determines that the chunk is not stored in the storage device 12 (step S104: No), the storage control unit 110 of the control device 11 stores the chunk in the storage device 12. That is, the storage control unit 110 transfers the chunk to the storage device 12 (step S105). In the storage device 12, when the storage unit 230 acquires a chunk, the acquired chunk is stored in the storage unit 210. The storage unit 230 acquires the hash value corresponding to the chunk together with the chunk, and stores the hash value in the hash table 220.

When the duplication determination unit 260 determines that the chunk has already been stored in the storage device 12 (step S104: Yes), the storage control unit 110 does not transfer the chunk to the storage device 12 and continues. Then, the process of step S106 is performed. The operation after step S106 may be performed only when it is determined in step S104 that the chunk is not stored in the storage device.

Next, the storage control unit 110 determines whether to store the above-mentioned chunk in the storage unit 140 that is a local storage unit (step S106).

If the storage control unit 110 stores the chunk in the storage unit 140 (step S106: Yes), the storage control unit 110 confirms whether or not there is free space in the storage unit 140 (step S107).

When there is no free space in the storage unit 140 (step S107: No), the storage control unit 110 deletes a part of the chunk stored in the storage unit 140 to secure the free space in the storage unit 140 ( Step S108). In step S108, the storage control unit 110 determines a chunk to be deleted based on the priority assigned to each chunk stored in the storage unit 140.

When the free space of the storage unit 140 is secured in the process of step S108, or when it is determined that the free space of the storage unit 140 is available in the process of step S107, the storage control unit 110 performs the process of step S109. Perform processing. That is, the storage control unit 110 gives a priority to the chunk and stores it in the storage unit 140. Subsequently, the storage control unit 110 stores the hash value corresponding to the chunk stored in the storage unit 140 in step S109 in the hash table (step S110).

Note that the storage control unit 110 may appropriately change the priority given to the chunk stored in the storage unit 140 according to the process of step S109.

Further, in step S106, when the storage control unit 110 does not store the chunk in the storage unit 140 (step S106: No), the storage control unit 110 ends the writing process.

In the process of step S101, the write target data is generally divided into a plurality of chunks. In this case, the control device 11 and the like perform the processing from step S102 onward for each of the plurality of chunks.

Next, the details of the read operation mainly by the control device 11 of the storage system 10 according to the first embodiment of the present invention will be described with reference to the flow chart shown in FIG.

First, the determination unit 120 queries the storage device 12 for the hash value corresponding to the chunk related to the read target data (step S201). In this case, the reply unit 240 of the storage device 12 transmits the hash value for the chunk regarding the read target data to the determination unit 120 based on the inquiry from the determination unit 120.

Next, the determination unit 120 determines whether the chunk related to the read target data is stored in the storage unit 140, which is a local storage unit, using the hash value acquired in step S201 (step S202). That is, the determination unit 120 compares the hash value returned from the reply unit 240 with each of the hash values stored in the hash table 150, and whether the chunk related to the read target data is stored in the storage unit 140. To judge.

The determination unit 120 determines that the chunk exists in the storage unit 140 when the hash value acquired in step S202 matches any of the hash values stored in the hash table 150 (step S202: Yes). In this case, the read control unit 130 reads the chunk from the storage unit 140 (step S203).

Further, the determination unit 120 determines that the chunk does not exist in the storage unit 140 when the hash value acquired in step S202 does not match any of the hash values stored in the hash table 150 (step S202: No). The read control unit 130 reads a chunk from the storage device 12 (step S204). The read control unit 130 acquires the chunk via the transfer unit 250 of the storage device 12.

When all the chunks related to the read target data have been read, the read control unit 130 combines the chunks and constructs the read target data (step S205). The read control unit 130 appropriately transmits the constructed data to the request source of the data, and ends the data read processing.

Although the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the above exemplary embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. The configurations in the respective embodiments can be combined with each other without departing from the scope of the present invention.

10 storage system 11 control device 12 storage device 110 storage control unit 120 determination unit 130 read control unit 140 storage unit 150 hash table 160 division unit 170 calculation unit 210 storage unit 220 hash table 230 storage unit 240 reply unit 250 transfer unit 260 duplication determination Part 500 Information processing device 501 CPU
502 ROM
503 RAM
504 program 505 storage device 506 recording medium 507 drive device 508 communication interface 509 communication network 510 input/output interface 511 bus

Claims (7)

Storage for storing a chunk into which data to be written to the storage device is divided and storing the chunk in the storage device when the chunk is not stored in the storage device, and assigning a priority to the storage means Control means,
Determination means for determining whether the chunk relating to the read target data is stored in the storage means based on the identification information transmitted from the storage device;
The determination means based on the determine the constant result of, and a read control means for constructing said read-target data by using the chunk stored in the storage means and said storage device,
The storage control means,
Determining the priority of the chunk stored in the storage means based on the type of the write target data,
When the write target data is backup data, the chunk related to the full backup data is given a higher priority compared to other chunks, and the chunk related to the incremental backup data is given a lower priority compared to other chunks. Is given
Furthermore, the priority for the chunk is determined based on the time since the chunk was stored in the storage means,
A control device for deleting, from the storage means, the chunk having the low priority when the free space of the storage means satisfies a predetermined condition . Said storage control means, in the storage device to determine the priority of the chunks said chunk is stored in the storage means based on whether the determination result stored in the storage device, according to claim 1 control device according to. The control device according to claim 1 or 2 , wherein the read control unit reads out from the storage unit and constructs the read target data when the read control unit stores the read target data when the read control unit stores the read target data. Comprising said storage means, the control device according to any one of claims 1 to 3. The control device according to any one of claims 1 to 3 ,
Reply means for transmitting, to the control device, identification information for identifying a chunk relating to the data to be read, based on a request from the control device,
Of the chunks relating to the data to be read, read control means for controlling to transmit the chunks that are not stored in the storage means of the control device to the control device,
A storage system comprising: a storage device comprising: The storage control means included in the computer stores a chunk into which the data to be written to the storage device is divided, in the storage device when the chunk is not stored in the storage device, and stores the chunk with priority. Control to store in the means,
The determination unit included in the computer determines whether the chunk related to the read target data is stored in the storage unit based on the identification information transmitted from the storage device.
Read control means included in the computer, said determining means based on the determine the constant result of a control method of constructing the read-target data by using the chunk stored in the storage means and said storage device,
The storage control means,
Determining the priority of the chunk stored in the storage means based on the type of the write target data,
When the write target data is backup data, the chunk related to the full backup data is given a higher priority compared to other chunks, and the chunk related to the incremental backup data is given a lower priority compared to other chunks. Is given
Furthermore, the priority for the chunk is determined based on the time since the chunk was stored in the storage means,
When the free space of the storage means satisfies a predetermined condition, the chunk with the low priority is deleted from the storage means.
Control method . On the computer,
A process for controlling a chunk into which the data to be written to the storage device is divided to be stored in the storage device when the chunk is not stored in the storage device, and to be stored in the storage unit with priority. When,
A process of determining whether the chunk relating to the read target data is stored in the storage unit based on the identification information transmitted from the storage device;
Based on the determine the constant results, a program for executing a process of constructing the read-target data by using the chunk stored in the storage means and said storage device,
In the control process,
Determining the priority of the chunk stored in the storage means based on the type of the write target data,
When the write target data is backup data, the chunk related to the full backup data is given a higher priority compared to other chunks, and the chunk related to the incremental backup data is given a lower priority compared to other chunks. Is given
Furthermore, the priority for the chunk is determined based on the time since the chunk was stored in the storage means,
When the free space of the storage means satisfies a predetermined condition, the chunk with the low priority is deleted from the storage means.
Program .

Images