JP7075067B2 - Storage device - Google Patents

Description

The present invention relates to a storage device, a data transfer method, and a recording medium.

A virtual storage medium (hereinafter referred to as a virtual storage medium) composed of an area of a storage medium connected to a storage device for the purpose of sharing and expanding storage in a computer system is provided by a host computer (hereinafter referred to as a virtual storage medium) via a network. It may be provided to a host (referred to as a host) (see, for example, Patent Document 1).

When such a storage device receives a read request specifying an access target area of the virtual storage medium from the host, such a storage device secures a buffer in the storage device, reads data from the access target area, and stores the data in the buffer. At this time, the storage device actually reads data from the storage medium area allocated to the access target area and stores it in the buffer. Then, when the storage device finishes storing all the read data in the buffer, the storage device starts the operation of reading the read data from the buffer and transferring the read data to the memory of the host via the network.

When the storage device receives a write request from the host that specifies the access target area of the virtual storage medium, the storage device secures a buffer in the storage device and transfers the write data stored in the host memory to the above buffer via the network. .. Then, when the storage device finishes storing all the write data in the buffer, the storage device reads the write data from the buffer and writes the write data in the access target area of the virtual storage medium. At this time, the storage device actually writes the write data to the storage medium area allocated to the access target area.

Re-special WO 2016/002325

However, in the above-mentioned storage device, in the case of a read request, the buffer is sent to the memory of the host only after all the read data in the storage medium area allocated to the access target area of the virtual storage medium has been stored in the buffer. Since the data transfer cannot be started, the read performance from the host to the virtual storage medium deteriorates.

Further, in the above-mentioned storage device, in the case of a write request, the buffer is buffered in the storage medium area allocated to the access target area of the virtual storage medium only after all the write data in the host memory is stored in the buffer. Since the above write data cannot be written, the write performance from the host to the virtual storage medium deteriorates.

An object of the present invention is to provide a storage device that solves the above-mentioned problem, that is, the problem that the access performance from the host to the virtual storage medium is lowered.

The storage device according to one embodiment of the present invention is
A controller that provides access to a virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from a host via a network.
A data transfer means between the node to which the controller is connected and the memory of the host is provided.
The controller divides the access target area on the virtual storage medium accessed by the access request into partial areas, secures a buffer for each partial area, and corresponds to the partial area for each partial area. Data transfer between the area of the storage medium and the buffer, and data transfer between the buffer corresponding to the partial area and the area corresponding to the partial area in the memory of the host by the data transfer means. It is configured to control.

Further, the data transfer method according to another aspect of the present invention is:
Between the node to which the controller is connected and the memory of the host, which provides access to the virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from the host via the network. It is a data transfer method of
The access target area on the virtual storage medium accessed by the access request is divided into partial areas.
Secure a buffer for each partial area
For each partial area, data transfer between the storage medium area corresponding to the partial area and the buffer corresponding to the partial area, and the buffer and the host corresponding to the partial area by the data transfer means. Data transfer to and from the area corresponding to the partial area in the memory of the above.

Further, the computer-readable recording medium according to another embodiment of the present invention is
Computer,
A controller that provides access to a virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from a host via a network.
It functions as a data transfer means between the node to which the controller is connected and the memory of the host.
The controller divides the access target area on the virtual storage medium accessed by the access request into partial areas, secures a buffer for each partial area, and corresponds to the partial area for each partial area. Data transfer between the area of the storage medium and the buffer corresponding to the partial area, and the area corresponding to the partial area in the memory of the host and the buffer corresponding to the partial area by the data transfer means. Records programs that are configured to control data transfer between.

By having the above-mentioned configuration, the present invention can improve the access performance from the host to the virtual storage medium.

It is a figure which shows the whole system configuration in the 1st Embodiment of this invention. It is a figure which shows the structure of the controller which executes the process for the access request from the application in 1st Embodiment of this invention. It is a figure which illustrates the format of the mapping table which manages the correspondence relation of the identifier and the address of the storage medium mapped to each area of the virtual storage medium in 1st Embodiment of this invention. It is a figure which illustrates the procedure in which the transfer storage area calculation unit calculates the address on the storage medium including the transfer storage area corresponding to the access request, and the address on the storage medium in the 1st Embodiment of this invention. It is a figure which illustrates the correspondence relationship of the transfer storage area and the head address of a transfer memory area calculated from the address which represents the area of the access target on the virtual storage medium and the access size in 1st Embodiment of this invention. It is a figure which illustrates the format of the access processing table which manages the information of the data transfer processing required for the access request from the application in the 1st Embodiment of this invention. It is a flowchart which showed the procedure which process | processed the access request from the application to the virtual storage medium in the controller in 1st Embodiment of this invention. It is a flowchart which showed the procedure which process | processed the access request from the application to the virtual storage medium in the controller in 1st Embodiment of this invention. It is a flowchart which showed the procedure which the access process execution management part included in a controller execute a data transfer process for an access request in 1st Embodiment of this invention. It is a flowchart which showed the procedure which the access process execution management part included in a controller execute a data transfer process for an access request in 1st Embodiment of this invention. It is a block diagram of the storage apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the hardware composition which realizes the controller and the data transfer part in the storage apparatus which concerns on 2nd Embodiment of this invention.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
The present embodiment is a technique for improving access performance by eliminating a bottleneck that occurs when accessing a virtual storage medium that is a combination of storage areas of a plurality of storage media via a network. Regarding. Hereinafter, the background techniques of the present embodiment, the problems to be solved by the present embodiment, the outline of the means for solving the problems, the configuration of the present embodiment, the operation of the present embodiment, and the effects of the present embodiment will be described in order. do.

[Background Technique of the present embodiment]
Access to virtual storage media is carried out, for example, through iSCSI (Internet Small Computer Interface) or NVM Express over Fabrics (Non-Volatile Memory Express over Fabrics; registered trademarks; registered trademarks such as NVM; hereinafter referred to as NVM-. These are protocols that extend the general storage medium standards SCSI (Small Computer Interface) and NVM Express (Non-Volatile Memory Express; registered trademark; hereinafter referred to as NVMe) to access via a network, and are virtual. The storage medium is provided with the same access means as the storage medium of each standard connected to the computer.

Further, in the access to these virtual storage media, RDMA (Remote Direct Memory Access) is used as a means for reducing the overhead in the data transfer process via the network. RDMA reduces the overhead of transfer processing by automatically transferring data to a memory address designated by a network card (RDMA Network Interface Card; hereinafter referred to as RNIC) between computers connected by a network. In iSER (iSCSI Extensions for RDMA) and NVMe-oF, which are the above-mentioned RDMA extensions of iSCSI, overhead is reduced by using RDMA for data transfer between the computer that provides the virtual storage medium and the computer that accesses the virtual storage medium. To improve access performance.

[Problems to be solved by this embodiment]
When RDMA is used for data transfer of a virtual storage medium, it is necessary to complete the storage of the data to be transferred before the start of RDMA so that the RNIC can automatically transfer the data. Therefore, when RDMA is used in the data transfer of the read access of the virtual storage medium, the RDMA transfer is started after waiting until all the data read from the storage medium is stored in the buffer which is the memory area to be transferred.

On the other hand, the virtual storage medium can be mapped to a region of a plurality of storage media such as RAID (Redundant Arrays of Expensive Disks). When a host accesses a virtual storage medium that is mapped to an area of a plurality of storage media, the area to be accessed may be mapped across a plurality of storage media. In this case, access is performed to each storage medium to be the mapping destination. That is, in the case of read access using RDMA for the above-mentioned data transfer, it is necessary to wait until the storage of the read result from all the storage media as the mapping destination in the buffer is completed and start the RDMA transfer.

That is, when the read access destination from the host to the virtual storage medium is mapped to a plurality of storage media, the read data of the storage medium that has been accessed cannot be transferred first, and the read performance from the host to the virtual storage medium deteriorates. .. In particular, when a storage medium whose access time changes greatly depending on the internal state, such as an SSD (Solid State Drive) using a NAND Flash as a storage element, is used, the more the number of storage media waiting for the completion of reading increases, the more the storage medium waits for the completion of reading. The waiting time until the start of RDMA transfer increases.

Further, even when RDMA is used for the write access to the virtual storage medium, the write to the storage medium cannot be started until the transfer of all the write data to the buffer is completed, and the write performance to the virtual storage medium is deteriorated. Since the data transfer by RDMA is controlled by RNIC, it is difficult to confirm the state of the write data during transfer. That is, when the write destination area is mapped to a plurality of storage media, the write access cannot be started first from the storage medium in which the data transfer from the host to the buffer is completed, which causes a deterioration in performance.

Therefore, when the access destination for the virtual storage medium is mapped to a plurality of storage media, the deterioration of the access performance due to the wait process before and after the RDMA transfer is a problem to be solved in the present embodiment.

[Outline of means for solving problems]
It is necessary to divide the read data and write data transfer processes in order to avoid or mitigate the wait process before and after the RDMA transfer, which causes the deterioration of the access performance of the virtual storage medium. By dividing the data transfer process, if it is a read access, the transfer can be started first from the data for which the read from the storage medium is completed. Further, in the case of write access, it is possible to individually start writing to the storage medium from the data that has been transferred from the host. On the other hand, the division of the data transfer process leads to an increase in overhead in the access process of the virtual storage medium. Therefore, it is desirable to divide the data transfer process into the minimum quantity necessary for avoiding the wait process.

In the present embodiment, there is a means for improving the access performance of the virtual storage medium by reducing the waiting process before and after the data transfer that occurs when the access destination of the virtual storage medium via the network is mapped to a plurality of storage media. offer. Therefore, regarding the processing of the access request to the virtual storage medium, the access to each storage medium corresponding to the access request destination and the RDMA transfer of the data related to the access are independently performed. By separating the processing related to the access request for each storage medium, the processing related to each storage medium can be performed in parallel without waiting for the processing related to other storage media in the access of the storage medium and the completion of the data transfer by RDMA. By making it, the completion time of access processing is shortened.

First, the host accessing the virtual storage medium determines the type of access request (read, write) and the type of access request (read, write) to the controller operating on the target node, which is a node different from the host, which provides access to the virtual storage medium. Access is requested by sending address information such as LBA (Logical Block Nodes) indicating the area to be accessed on the virtual storage medium.

When the controller receives the access request from the host, the controller identifies the identifier of the storage medium corresponding to each part of the area to be accessed and the address indicating the area in the storage medium as the transfer storage area. Further, the controller obtains an offset from the beginning of the transfer storage area of each storage medium, which represents a corresponding portion in the access target area of the virtual storage medium.

In addition, the controller receives address information indicating the memory area for storing read data or write data on the host for the area to be accessed of the virtual storage medium in advance or together with an access request. Then, the controller obtains the address on the memory address space of the host corresponding to each transfer storage area as the transfer memory area from the above address information. The address of each transfer memory area is obtained as an address on the memory space represented by an offset from the beginning in the area to be accessed of the virtual storage medium.

Further, the controller secures a transfer buffer, which is a buffer for relaying transfer data, for each set of the transfer storage area and the transfer memory area on the memory of the target node. That is, a transfer buffer is secured for each storage medium that is a map destination of the access target area of the virtual storage medium. The controller stores read data and write data for the storage medium in the transfer buffer, and transfers data to and from the transfer storage area. Further, the controller instructs RNIC to transfer read data and write data by RDMA between the transfer buffer and the transfer memory area of the host.

When the access request from the host is a read, the controller makes read access to each storage medium corresponding to each part of the area to be accessed, and stores the data in the transfer storage area in the transfer buffer. Then, the controller instructs the RNIC to transfer the read data to and from the transfer memory area of the host for the transfer buffer corresponding to the storage medium for which the read access is completed. At this time, the controller starts RDMA transfer of the read data regardless of whether the storage of the read data from the transfer storage to the other transfer buffer is completed or incomplete. When the RDMA transfer from the transfer buffer to the transfer memory area is completed for all the read data, the controller notifies the host of the completion of the read access request.

On the other hand, when the access request from the host is a write, the controller instructs the RNIC to transfer the write data to RDMA between the transfer memory area of the host corresponding to each part of the access target area and the corresponding transfer buffer. Then, the controller performs write access in order from the storage medium corresponding to the transfer buffer in which the RDMA transfer is completed, and stores the write data in the transfer storage area. At this time, the controller starts the write access of the storage medium regardless of whether the RDMA transfer of the write data in the other transfer buffer is completed or incomplete. When the storage of all the write data from the transfer buffer to the transfer storage area on the storage medium is completed, the controller notifies the host of the completion of the write access request.

[Structure of this embodiment]
FIG. 1 is a diagram illustrating a configuration of a storage system according to a first embodiment of the present invention. Referring to FIG. 1, the computer system according to the present embodiment includes a host 1, a target node 2, and a network 3. Host 1 is also called a host computer. The target node 2 is also referred to as a target computer or a storage device.

The host 1 has a host memory 10 and a host communication unit 11. The host 1 operates an application 12 that requests access to the virtual storage medium 23 to the target node 2.

The host memory 10 is a memory connected to the host 1. The host memory 10 is accessed from the application 12. The host memory 10 has an area for storing read data that is the result of a read request from the application 12 to the virtual storage medium 23 and write data written by the write request. This area is defined as a transfer memory area. The host memory 10 is a storage device such as a DRAM used as the memory of the host 1. Alternatively, the host memory 10 may be, for example, a GPU, FPGA, or other device that is connected to the host 1 directly or via a network and performs input / output via the memory address space of the host 1.

The host communication unit 11 transmits / receives data between the host 1 and the target node 2 via the network 3. Further, the host communication unit 11 performs RDMA transfer between the host memory 10 and the target memory 20 connected to the target node 2.

Application 12 is software or hardware running on host 1. The application 12 requests the target node 2 to access the virtual storage medium 23.

The target node 2 has a target memory 20, a target communication unit 21, a controller 22, and a storage medium 24.

The target memory 20 is a memory connected to the target node 2. The target memory 20 is used as a buffer for storing read data and write data for the virtual storage medium 23. This buffer is defined as the target buffer.

The target communication unit 21 transmits / receives data between the target node 2 and the host 1 via the network 3. Further, the target communication unit 21 performs RDMA transfer between the target memory 20 and the host memory 10 connected to the host 1.

The controller 22 is software or hardware that operates on the target node 2. The controller 22 performs access processing for the virtual storage medium 23. The controller 22 receives an access request from the application 12 to the virtual storage medium 23. In order to execute the access request, the controller 22 controls access to each area of the storage medium 24 corresponding to the access request destination, and transfer of read data and write data between the host memory 10 and the target memory 20. ..

The virtual storage medium 23 is a virtual storage medium constructed from the area of the storage medium 24 by the controller 22. The virtual storage medium 23 is recognized and accessed as a storage medium from the application 12 of the host 1 via the network 3. An area on the virtual storage medium 23 accessed from the application 12 is defined as an access target area.

The storage medium 24 is mapped to the area of the virtual storage medium 23. The area of the storage medium 24 to which the access target area of the virtual storage medium 23 is mapped is defined as a transfer storage area. The storage medium 24 is a device such as an SSD (Solid State Drive) connected to the target node 2 via a bus or a network. The storage medium 24 is not limited to the configuration of the single device shown in FIG. 1, and a plurality of storage media 24 may exist.

The network 3 connects the host 1 and the target node 2 to each other. Network 3 supports RDMA transfers between host 1 and target node 2. Further, the network 3 is not limited to the form in which only the host 1 and the target node 2 are connected as shown in FIG. For example, a node (computer) other than the host 1 and the target node 2 may be connected to the network 3. Further, the host 1 and the target node 2 may be connected via a switch.

Next, in the computer system according to the present embodiment, the configuration in which the controller 22 receives an access request to the virtual storage medium 23 from the application 12 running on the host 1 and executes the configuration is described in FIGS. 2, 3, 4, 5, and 5. This will be described with reference to FIG.

Referring to FIG. 2, the controller 22 includes an access request receiving unit 221, a mapping table 222, a transfer storage area calculation unit 223, a transfer memory area calculation unit 224, an access processing table 225, and an access processing execution management unit 226. And a data transfer control unit 227. Further, the target memory 20 includes a target buffer 200.

The access request receiving unit 221 receives an access request from the application 12 running on the host 1. The access request includes the type of access request indicating whether it is a read or a write. Further, the access request includes a logical address indicating the beginning of the access target area on the virtual storage medium 23. Further, the access request includes a memory address pointing to the beginning of a storage area (transfer memory area) of read data or write data on the host memory 10 corresponding to the access target area. However, the address information of the transfer memory area corresponding to the access target area does not need to be included in the access request, and may be received in advance before the application 12 makes the access request. The access request receiving unit 221 controls the transfer storage area calculation unit 223, the transfer memory area calculation unit 224, the access processing table 225, and the access processing execution management unit 226 in order to process the received access request.

The mapping table 222 includes an identifier of the storage medium 24 mapped to each area (hereinafter, referred to as a block) on the virtual storage medium 23, and an address (hereinafter, a physical address) in the storage medium 24 specified by the identifier. The correspondence between (called) and the logical address in the virtual storage medium 23 is stored and managed in advance.

FIG. 3 is a diagram illustrating the information contained in the mapping table 222. The mapping table 222 records the identifier of the mapping destination storage medium 24, the correspondence between the logical address of the block in the virtual storage medium 23 and the physical address in the mapping destination storage medium 24 for each block on the virtual storage medium 23. Includes the mapping entry 2221 made. The block on the virtual storage medium 23 managed by one mapping entry 2221 in the mapping table 222 is called a logical block, and the block of the storage medium 24 mapped to the logical block is called a physical block. Each mapping entry 2221 is a storage medium identifier 2223 representing an identifier of a logical address 2222 which is a start address of each logical block of the virtual storage medium 23, a storage medium 24 which is a mapping destination of each logical block, and a storage medium identifier thereof. In the storage medium 24 represented by 2223, the physical address 2224 which is the start address of the physical block to be mapped and the mapping size 2225 which represents the size of the logical block to be mapped and the physical block are included.

For example, in the mapping entry 2221 in the first row of the mapping table 222, a logical block having a size of 64 MiB having a logical address 0x00400000 in the virtual storage medium 23 as a head address has a physical address 0x08000000 in the storage medium 24 of the storage medium identifier 1. It means that it is mapped to a physical block with a size of 64 MiB. Further, in the mapping entry 2221 in the second row of the mapping table 222, the logical block having a size of 128 MiB having the logical address 0x00800000 in the virtual storage medium 23 as the head address has the physical address 0xa00000 in the storage medium 24 of the storage medium identifier 1 at the head. It indicates that it is mapped to a physical block having a size of 128 MiB as an address.

As illustrated in the mapping entry 2221 in the first row of the mapping table 222 of FIG. 3, one logical block in the virtual storage medium 23 is mapped to the storage area of at most one storage medium 24. Further, as illustrated in the mapping entries 2221 in the first row and the second row of the mapping table 222 in FIG. 3, two logical blocks having adjacent logical addresses in the virtual storage medium 23 are mapped to storage media different from each other. ing. In this way, by mapping each logical block in the virtual storage medium 23 to the storage area of at most one storage medium 24 and mapping the two adjacent logical blocks to different storage media, the data transfer process can be performed. The split can be the minimum quantity required to avoid the wait process.

The format of the mapping table 222 is not limited to the format shown in FIG. The mapping table 222 may be in any format as long as it can determine the correspondence between the identifier and the logical address of the storage medium 24 corresponding to each logical block of the virtual storage medium 23 and the physical address. For example, when each mapping entry 2221 corresponds to each logical block in which the area of the virtual storage medium 23 is divided by a fixed size from the beginning, the logical address 2222 and the mapping size 2225 for each logical block are unnecessary. It is also possible to use RAID for mapping between the virtual storage medium 23 and the storage medium 24. In that case, for example, in the case of RAID 0, the number of storage media 24 constituting the stripe and the mapping corresponding to the virtual storage medium 23 from the chunk size, which is a region continuously mapped to each storage medium 24. The destination can be calculated. At this time, the information of each entry in the mapping table 222 excluding the RAID configuration information is unnecessary.

The transfer storage area calculation unit 223 is an identifier of a storage medium 24 having a physical block assigned to a logical block including the logical address from a certain logical address of the access target area of the virtual storage medium 23 based on the mapping table 222. And the physical address corresponding to the logical address, and the size mapped from the physical address to the continuous area of the storage medium 24 are determined. Further, the transfer storage area calculation unit 223 calculates an offset from the beginning indicating the position of the area corresponding to the transfer storage area in the access request destination area.

FIG. 4 is an operation explanatory diagram of the transfer storage area calculation unit 223. Referring to FIG. 4, one logical block 41L of the virtual storage medium 23 is assigned to one physical block 41P of the storage medium 24. The first logical address of the logical block 41L is Lb, the first physical address of the physical block 41P is Pb, and the identifier of the storage medium 24 is x. When the logical address La on the logical block 41L is given from the access request receiving unit 221, the transfer storage area calculation unit 223 refers to the mapping entry 2221 corresponding to the logical block 41L in the mapping table 42 to obtain the logical address La. The identifier x of the storage medium 24 assigned to the included logical block is determined. Further, the transfer storage area calculation unit 223 obtains an offset (La-Lb) of the logical address La by subtracting the first logical address Lb of the logical block 41L from the logical address La. Then, the transfer storage area calculation unit 223 adds the offset to the physical address Pb at the head of the physical block 41P to calculate the physical address Pa corresponding to the logical address La. That is, Pa = Pb + (La−Lb). For example, when the logical address La is the start address of the access target area specified in the access request of the application 12, the physical address Pa points to the start of the transfer storage area 43, and the offset (La-Lb) indicates the transfer storage area 43. Indicates the offset of. Further, when the mapping size of the logical block 41L and the physical block 41P is MS, the transfer storage area calculation unit 223 sets the size mapped from the physical address Pa to the continuous area of the storage medium 24 of the identifier x to MS- (La-). Calculate as Lb).

When the access target area of the virtual storage medium 23 is mapped to the transfer storage area of the plurality of storage media 24, the transfer memory area calculation unit 224 sets the address of the transfer memory area on the host memory 10 corresponding to each transfer storage area. calculate.

FIG. 5 is an operation explanatory diagram of the transfer memory area calculation unit 224, which is an access target area 51 on the virtual storage medium 23 and a transfer storage area 52a on the storage media 24a, 24b, 24c mapped to the access target area 51. , 52b, 52c and an example of the relationship between the transfer memory area 53 on the host memory 10 corresponding to the access target area 51 are shown. In the example of FIG. 5, the area of size Sa from the beginning of the access target area 51 is mapped to the storage medium 24a. Further, the area of the size Sb following the access target area 51 is mapped to the storage medium 24b. Further, the remaining size Sc area of the access target area 51 is mapped to the storage medium 24c. In the present embodiment, when an access request is made to the access target area 51 from the application 12, the access target area 51 is divided into three areas having the sizes of Sa, Sb, and Sc, and data transfer is performed in each division unit. conduct. Therefore, the transfer memory area 53 is divided into three areas having the sizes of Sa, Sb, and Sc for use. The transfer memory area calculation unit 224 calculates the start address of each divided area formed when the transfer memory area 53 is divided in this way.

The transfer memory area calculation unit 224 sets the logical address of the divided area on the access target area 51 of the virtual storage medium 23 to Lx, the offset from the beginning of the access target area 51 to the logical address Lx to OF, and the beginning of the transfer memory area 53. Assuming that the address is M, the address Mx of the transfer memory area 53 corresponding to the logical address Lx is calculated as Mx = M + OF.

The access processing table 225 manages information on data transfer processing necessary for processing each access request from the application 12 to the virtual storage medium 23. The access processing table 225 is updated from the access request receiving unit 221 and referred to by the access processing execution management unit 226 and the data transfer control unit 227. FIG. 6 is a diagram illustrating information contained in the access processing table 225. The access processing table 225 stores an access request entry 2251 corresponding to each access request from the application 12 on a one-to-one basis. Each access request entry 2251 includes an access type 2252 and a transfer pair list. The transfer pair list includes one or more transfer pairs 2253 representing a pair of transfer memory areas and transfer storage areas related to an access request. The access request entry 2251 includes a transfer pair 2253 for each pair of a plurality of transfer memory areas and transfer storage areas as a result of the access request from the application 12 being divided into a plurality of parts. Further, the transfer pair 2253 has a memory address 2254 indicating the beginning of the transfer memory area on the host memory 10, a storage identifier 2255 indicating the storage medium 24 including the transfer storage area, a storage medium address 2256 indicating the beginning of the transfer storage area, and It is composed of a transfer size 2257 that represents the size of the transfer data.

The format of the access processing table 225 is not limited to the format shown in FIG. For example, the access type 2252 may be used as a flag for write access, the access with the flag set may be written, and the access without the flag may be read. Further, the transfer pair 2253 may include a flag indicating that the data transfer has been completed.

The access processing execution management unit 226 manages the execution status of data transfer necessary for processing the access request from the application 12 to the virtual storage medium 23 with reference to the access processing table 225. The access processing execution management unit 226 selects an unprocessed transfer pair 2253 from the access processing table 225 and secures the target buffer 200 on the target memory 20. Then, the data transfer control unit 227 starts the transfer process of read data or write data between the transfer memory area and the transfer storage area. Further, the access process execution management unit 226 releases the secured target buffer 200 when the data transfer process relating to the transfer pair 2253 is completed.

The data transfer control unit 227 transfers data between the transfer memory area on the host memory 10 and the secured target buffer 200, and stores the target buffer 200 and the transfer pair 2253 instructed by the access process execution management unit 226. Data transfer is performed to and from the transfer storage area on the medium 24.

When the access type 2252 for the transfer pair 2253 is read, the data transfer control unit 227 first makes read access to the storage medium 24 represented by the storage identifier 2255, and reads data from the transfer storage area to the target buffer 200. To transfer. Then, when the data transfer to the target buffer 200 is completed, the data transfer control unit 227 then instructs the target communication unit 21 to transfer the read data stored in the target buffer 200 to the transfer memory area of the host memory 10. do.

On the other hand, when the access type 2252 for the transfer pair 2253 is write, the data transfer control unit 227 first instructs the target communication unit 21 to use the write data stored in the transfer memory area of the host memory 10 as the target buffer. Transfer to 200. Then, when the data transfer to the target buffer 200 is completed, the data transfer control unit 227 performs write access to the storage medium 24 represented by the storage identifier 2255, and writes write data from the target buffer 200 to the transfer storage area. Forward.

The target buffer 200 is secured on the target memory 20 for each transfer pair 2253. The target buffer 200 temporarily holds read data or write data transferred between the transfer memory area and the transfer storage area.

[Operation of this embodiment]
Next, an operation of processing an access request from the application 12 to the virtual storage medium 23 in the embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 6, 6, 7A, and 7B.

The application 12 transmits an access request to the virtual storage medium 23 of the target node 2 to the host communication unit 11. This access request includes the following parameters:
(A) Type of access request (b) Logical address indicating the access target area on the virtual storage medium 23 (c) Size of the access target area (d) On the memory space of the host 1 corresponding to the access target area Address pointing to the area

There are two types of access requests: read and write. The logical address indicating the access target area is the first logical address of the access target area. That is, the access target area has consecutive logical addresses, and the first logical address thereof is specified in the access request. The address indicating the area on the memory space of the host 1 corresponding to the access target area is the start address of the memory area of the host memory 10 that stores the read data that is the result of the read request or the write data written by the write request. ..

The host communication unit 11 transmits the access request received from the application 12 to the target communication unit 21 of the target node 2 through the network 3. The target communication unit 21 transmits the received access request to the controller 22.

The access request receiving unit 221 of the controller 22 receives an access request to the virtual storage medium 23 from the application 12 (step S101).

Next, the access request receiving unit 221 creates an access request entry 2251 corresponding to the access request received in step S101 on the access processing table 225, and the access type included in the received access request in the access type 2252 column. Is registered (step S102). At this point, the access request receiving unit 221 leaves the field of the transfer pair list of the created access request entry 2251 blank.

Next, the access request receiving unit 221 initializes the offset representing the point of interest in the transfer storage area and the transfer memory area to 0 (step S103). Then, the access request receiving unit 221 pays attention to the initialized offset.

Next, the access request receiving unit 221 pays attention to the access target area on the virtual storage medium 23 by adding the value of the attention offset to the logical address of the head of the access target area in the virtual storage medium 23 included in the access request. Calculate the logical address of the point. (Step S104)

Next, the access request receiving unit 221 notifies the transfer storage area calculation unit 223 of the logical address of the point of interest on the virtual storage medium 23 obtained in step S104. The transfer storage area calculation unit 223 refers to the mapping table 222, and refers to the identifier of the storage medium 24 including the transfer storage area and the transfer storage area corresponding to the logical address of the point of interest on the notified virtual storage medium 23. The physical address of the point of interest in is obtained (step S105).

Next, the access request receiving unit 221 notifies the transfer memory area calculation unit 224 of the start address of the memory area of the host memory 10 and the offset during attention. The transfer memory area calculation unit 224 adds the attention-grabbing offset to the notified start address of the memory area of the host memory 10, and the transfer memory of the host memory 10 corresponding to the logical address of the point of interest on the virtual storage medium 23. The address of the point of interest in the region is obtained (step S106).

Next, the transfer storage area calculation unit 223 calculates the size mapped to the continuous area of the storage medium 24 from the logical address of the point of interest on the virtual storage medium 23 notified above with reference to the mapping table 222. Step S107). Specifically, first, the transfer storage area calculation unit 223 determines the mapping entry 2221 corresponding to the logical block of the virtual storage medium 23 including the logical address of the point of interest. Next, the transfer storage area calculation unit 223 calculates the difference between the logical address of the point of interest and the logical address 2222 of the corresponding mapping entry 2221 determined above. Then, the transfer storage area calculation unit 223 calculates the size mapped to the continuous area by subtracting the calculated difference from the mapping size 2225 of the corresponding mapping entry 2221.

Next, the access request receiving unit 221 performs the following processing (step S108). First, the access request receiving unit 221 calculates a value obtained by subtracting the attention-grabbing offset from the size of the access target area specified in the access request as the untransferred area size. Next, the access request receiving unit 221 compares the untransferred area size with the size mapped to the continuous area of the storage medium obtained in step S107. Next, the access request receiving unit 221 determines the minimum value of the above two sizes as the size of the transfer data.

Next, the access request receiving unit 221 obtained the identifier of the storage medium 24 obtained in step S105, the physical address of the point of interest in the transfer storage area, the address of the point of interest in the transfer memory area obtained in step S106, and the address of the point of interest in step S108. The combination of transfer data sizes is registered in the transfer pair 2253 column of the access request entry 2251 created in the access processing table 225 in step S102 (step S109). That is, the identifier of the storage medium 24, the physical address of the point of interest in the transfer storage area, the address of the point of interest in the transfer memory area, and the size of the transfer data are the storage identifier 2255, the storage medium address 2256, and the memory address 2254 in the transfer pair 2253, respectively. , Corresponds to the transfer size 2257.

Next, the access request receiving unit 221 adds the size of the transfer data obtained in step S108 to the offset during attention (step S110). Then, the access request receiving unit 221 shifts its attention to the offset after the addition.

Next, the access request receiving unit 221 compares the value of the offset during attention with the size of the access target area specified by the access request. When the value of the offset during attention is less than the size of the access target area (Yes determination in step S111), the access request receiving unit 221 re-executes the process from step S104.

On the other hand, when the value of the offset being focused is equal to or larger than the size of the area to be accessed (No determination in step S111), the access request receiving unit 221 accesses the access processing execution management unit 226 to perform an access processing table. The access request entry 2251 of 225 is instructed (step S112).

The access processing execution management unit 226 refers to the access processing table 225 and executes processing for the access request according to the access request entry 2251 instructed in step S112 (step S113).

When the processing for the access request according to the access request entry 2251 instructed by the access processing execution management unit 226 is completed, the access request receiving unit 221 deletes the instructed access request entry 2251 registered in the access processing table 225. Further, the access request receiving unit 221 notifies the application 12 operating on the host 1 that has made the access request related to the access request entry 2251 of the completion of the access request, and ends the operation (step S114).

By performing the above steps S101 to S114, the operation of processing the access request from the application 12 to the virtual storage medium 23 in the embodiment of the present invention is completed. The processing order from steps S101 to S114 does not necessarily have to be the order shown in FIGS. 7A and 7B. For example, the processes of steps S104 to S105, step S106, and step S107 can be executed at the same time, or can be executed in a different order. Further, the address indicating the area on the memory space of the host 1 received from the application 12 in step S101 may be received before the access request.

Next, an access request from the application 12 shown in FIGS. 7A and 7B to the virtual storage medium 23 in the embodiment of the present invention with reference to FIGS. 1, 2, 3, 6, 6, 8A, and 8B. In the operation of processing the above, the operation of executing the processing for the access request by the access processing execution management unit 226 in step S113 will be described.

The access processing execution management unit 226 refers to the access request entry 2251 corresponding to the access request to be processed in the access processing table 225, and selects one arbitrary transfer pair 2253 (step S201). Then, the access processing execution management unit 226 pays attention to the selected transfer pair 2253.

Next, the access processing execution management unit 226 secures a target buffer 200 having a transfer size of 2257 or more in the attention transfer pair 2253 on the target memory 20 for the attention transfer pair 2253 (step S202). ..

Next, the access process execution management unit 226 instructs the data transfer control unit 227 to execute the data transfer process of the attention transfer pair 2253 (step S203).

When the access type 2252 of the access request to be processed is a read (Yes determination in step S204), the data transfer control unit 227 performs the following processing (step S205). First, the data transfer control unit 227 refers to the access processing table 225 and acquires the storage identifier 2255, the storage medium address 2256, and the transfer size 2257 of the attention transfer pair 2253. Next, the data transfer control unit 227 requests a read from the storage medium 24 pointed to by the storage identifier 2255 of the attention transfer pair 2253. In this read request, the storage medium address 2256 and the transfer size 2257 of the transfer pair 2253 being focused on are specified to specify the transfer storage area to be read-accessed, and the storage destination of the read data is specified in step S202. Specify the start address of the secured target buffer 200.

The storage medium 24 instructed to read access in step S205 reads data from the transfer storage area having the designated storage medium address 2256 as the head and the designated transfer size 2257 as the head, and the designated target buffer 200. Read data is stored in the data transfer control unit 227, and the completion is notified to the data transfer control unit 227 (step S206).

After confirming that the read data has been stored in the target buffer 200, the data transfer control unit 227 instructs the target communication unit 21 to transfer data from the target buffer 200 to the transfer memory area of the host memory 10 (step S207). .. In the transfer instruction, the data transfer control unit 227 designates the start address of the target buffer 200 and the transfer size 2257 of the attention transfer pair 2253 as the transfer source to the target communication unit 21. Further, in the above transfer instruction, the data transfer control unit 227 designates the memory address 2254 of the attention-grabbing transfer pair 2253 as the transfer destination for the target communication unit 21.

The target communication unit 21 performs the following data transfer according to the transfer instruction (step S208). First, the target communication unit 21 reads the read data stored in the target buffer 200 designated as the transfer source, transfers the read data to the host communication unit 11 connected by the network 3, and the host designated as the transfer destination. Instructs storage in the area specified by the memory address 2254 of the memory 10. The host communication unit 11 receives an instruction from the target communication unit 21 and stores the read data in the transfer memory area designated by the memory address 2254 of the host memory 10. When the storage of the read data in the transfer memory area by the host communication unit 11 is completed, the target communication unit 21 notifies the data transfer control unit 227 of the completion of the data transfer. Then, the process proceeds to step S213.

On the other hand, when the access type 2252 of the access request to be processed is write (No determination in step S204), the data transfer control unit 227 performs the following processing (step S209). First, the data transfer control unit 227 refers to the access processing table 225 and acquires the memory address 2254 and the transfer size 2257 of the attention transfer pair 2253. Next, the data transfer control unit 227 instructs the target communication unit 21 to transfer the data from the host memory 10 to the target buffer 200. In the transfer instruction, the data transfer control unit 227 designates the memory address 2254 of the attention transfer pair 2253 and the transfer size 2257 of the attention transfer pair 2253 as transfer sources to the target communication unit 21. Further, in the above transfer instruction, the data transfer control unit 227 designates the start address of the target buffer 200 as the transfer destination for the target communication unit 21.

The target communication unit 21 performs the following transfer according to the transfer instruction (step S210). First, the target communication unit 21 reads write data from the transfer memory area specified by the memory address 2254 of the host memory 10 and the transfer size 2257 through the host communication unit 11 and stores the write data in the target buffer 200 via the network 3. Next, the target communication unit 21 notifies the data transfer control unit 227 of the completion of storage of the write data in the target buffer 200.

After confirming that the write data has been stored in the target buffer 200, the data transfer control unit 227 requests the storage medium 24 pointed to by the storage identifier 2255 of the attention transfer pair 2253 to write from the target buffer 200 to the storage medium 24. (Step S211). In this write request, the data transfer control unit 227 designates the start address of the target buffer 200 and the transfer size 2257 of the attention transfer pair 2253 as the write source for the storage medium 24. Further, the data transfer control unit 227 designates the storage medium address 2256 of the attention-grabbing transfer pair 2253 as the write destination in the write request.

The storage medium 24 for which the write is requested in step S211 performs the designated write access, and stores the write data of the designated target buffer 200 in the transfer storage area having the designated storage medium address 2256 as the start address. Then, the completion is notified to the data transfer control unit 227 (step S212). After that, the process proceeds to step S213.

In step S213, the data transfer control unit 227 notifies the access process execution management unit 226 of the completion of execution of the transfer process regarding the attention transfer pair 2253.

The access process execution management unit 226 releases the target buffer 200 reserved for the attention-grabbing transfer pair 2253 for which the execution of the transfer process has been completed (step S214). Further, the access processing execution management unit 226 deletes the information regarding the attention-grabbing transfer pair 2253 for which the execution of the transfer processing has been completed from the access request entry 2251 corresponding to the access request to be processed in the access processing table 225 (step S215). ..

Next, the access processing execution management unit 226 confirms the number of transfer pairs 2253 included in the access request entry 2251 corresponding to the access request to be processed (step S216). When the number of transfer pairs 2253 confirmed in step S216 is one or more (Yes determination in step S217), the access process execution management unit 226 re-executes the process from step S201. Further, when the number of transfer pairs 2253 confirmed in step S216 is 0 (No determination in step S217), the access processing execution management unit 226 notifies the access request receiving unit 221 that the access request processing is completed. , End the operation (step S218).

By performing the above processes from steps S201 to S218, the operation of executing the process for the access request by the access process execution management unit 226 in step S113 in the embodiment of the present invention is completed. The processing order from steps S201 to S218 does not necessarily have to be the order shown in FIGS. 8A and 8B. For example, the processes of steps S214 and S215 can be executed at the same time, or can be executed in a different order. Further, the processes from step S201 to step S215 may be executed in parallel for a plurality of transfer pairs 2253.

[Effect of this embodiment]
By applying this embodiment, when an access destination is mapped to a plurality of storage media in an access from a host to a virtual storage medium in which storage areas of a plurality of storage media are combined, a wait process occurs before and after the RDMA transfer. Can be avoided and the access performance can be improved. Further, the data transfer between the area of the storage medium and the buffer and the data transfer between the buffer and the memory of the host can be parallelized.

[Second Embodiment]
FIG. 9 is a block diagram of the storage device 6 according to the second embodiment of the present invention. The storage device 6 includes a controller 61, a memory 62, a virtual storage medium 63, a plurality of storage media 64, and a data transfer unit 65. The storage device 6 is connected to the host computer 8 via the network 7 so as to be able to communicate with each other.

The virtual storage medium 63 is a virtual storage medium composed of regions of a plurality of storage media 64. The data transfer unit 65 is configured to transfer data between the storage device 6 and the host memory 81 of the host computer 8 via the network 7. The memory 62 is used as a buffer 621 for temporarily storing the data read from the virtual storage medium 63 or the data to be written to the virtual storage medium 63.

The controller 61 provides access to the virtual storage medium 63. The controller 61 receives an access request to the virtual storage medium 63 from the host computer 8 via the network 7. The controller 61 controls the virtual storage medium 63, the storage medium 64, the memory 62, and the data transfer unit 65 in order to perform processing according to the received access request. For example, the controller 61 divides the access target area on the virtual storage medium 63 accessed by the access request into one or more partial areas. Further, the controller 61 secures a buffer 621 for each partial area in the memory 62. Further, the controller 61 controls data transfer between the area of the storage medium 64 corresponding to the partial area and the buffer 621 corresponding to the partial area for each partial area of the virtual storage medium 63. Further, the controller 61 controls data transfer between the buffer 621 corresponding to the partial area by the data transfer unit 65 and the area corresponding to the partial area in the host memory 81 for each partial area of the virtual storage medium 63.

As shown in FIG. 10, for example, the controller 61 and the data transfer unit 65 include an information processing device 930 having an arithmetic processing unit 910 such as one or more microprocessors, a storage unit 920 such as a memory or a hard disk, and a program 940. Can be realized with. The program 940 is read into the memory from an external computer-readable recording medium at the time of starting up the information processing apparatus 930, and controls the operation of the arithmetic processing unit 910 so that the controller 61, And the data transfer unit 65 is realized.

The storage device 6 configured as described above operates as follows.

When the controller 61 of the storage device 6 receives an access request to the virtual storage medium 63 from the host computer 8 via the network 7, the access target area on the virtual storage medium 63 is divided into partial areas. Preferably, the controller 61 divides the access target area on the virtual storage medium 63 into a partial area composed of at most one storage medium 64 area. Further, preferably, the controller 61 divides the access target area on the virtual storage medium 63 into the partial areas so that the number of the partial areas is minimized.

Next, the controller 61 secures a buffer 621 for each partial area in the memory 62. Next, the controller 61 transfers data between the area of the storage medium 64 corresponding to the partial area and the buffer 621 corresponding to the partial area for each partial area. Further, the controller 61 transfers data between the buffer 621 corresponding to the partial area by the data transfer unit 65 and the area corresponding to the partial area in the host memory 81.

For example, when the type of access request is a read request, the controller 61 transfers data from the area of the storage medium 64 corresponding to the partial area to the buffer 621 corresponding to the partial area for each partial area, and transfers the data. After the completion of, data transfer from the buffer 621 to the area corresponding to the partial area in the host memory 81 is started. Further, for example, when the type of the access request is a write request, the controller 61 transfers data from the area corresponding to the partial area in the host memory 81 to the buffer 621 corresponding to the partial area for each partial area. After the data transfer is completed, the data transfer from the buffer 621 to the area of the storage medium 64 corresponding to the partial area is started.

As described above, according to the storage device 6 according to the present embodiment, the access performance from the host computer 8 to the virtual storage medium 63 is improved. The reason is that the storage device 6 divides the access target area on the virtual storage medium 63 accessed by the access request into partial areas, secures a buffer 621 for each partial area, and corresponds to the partial area for each partial area. To transfer data between the area of the storage medium 64 and the buffer 621 corresponding to the partial area, and to transfer data between the buffer 621 corresponding to the partial area and the area corresponding to the partial area in the host memory 81. In the case of a read request, data transfer from the partial area in which the read data is stored in the buffer 621 to the host memory can be started, and in the case of a write request, the partial area in which the write data is stored in the buffer 621 is written to the recording medium. This is because you can start.

Although the present invention has been described above with reference to each of the above embodiments, the present invention is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the present invention.

The present invention enjoys the benefit of priority claim based on the patent application of Japanese Patent Application No. 2018-119240, which was filed in Japan on June 22, 2018, and is described in the patent application. All contents are included in this specification.

INDUSTRIAL APPLICABILITY The present invention can be used for a service or the like to provide a virtual storage medium composed of an area of a storage medium connected to a computer to another computer via a network.

Some or all of the above embodiments may also be described, but not limited to:
[Appendix 1]
A controller that provides access to a virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from a host via a network.
A data transfer means between the node to which the controller is connected and the memory of the host is provided.
The controller divides the access target area on the virtual storage medium accessed by the access request into partial areas, secures a buffer for each partial area, and corresponds to the partial area for each partial area. Data transfer between the area of the storage medium and the buffer corresponding to the partial area, and the area corresponding to the partial area in the memory of the host and the buffer corresponding to the partial area by the data transfer means. A storage device that is configured to control data transfer between.
[Appendix 2]
The storage device according to Appendix 1, wherein in the division, the controller divides the access target area into the partial area composed of at most one storage medium area.
[Appendix 3]
The storage device according to Appendix 2, wherein the controller is divided so that the number of the partial areas is minimized in the division.
[Appendix 4]
The controller
The type of the access request from the host, the first address information indicating the access target area, and the second address information indicating the transfer memory area on the memory for transmitting / receiving data between the access target area and the access target area. The storage device according to Appendix 3, further comprising an access request receiving means for acquiring and.
[Appendix 5]
The controller
The access target area is divided into the partial areas composed of at most one area of the storage medium, the size of each of the partial areas, the identifier of the storage medium corresponding to the respective partial areas, and the storage. The storage device according to Appendix 4, further comprising a transfer storage area calculation means for obtaining a third address information indicating a transfer storage area which is an area of a medium.
[Appendix 6]
The controller
The appendix 5 is provided with a transfer memory area calculation means for dividing the transfer memory area into partial transfer memory areas corresponding to the respective partial areas and obtaining a fourth address information indicating each of the partial transfer memory areas. Storage device.
[Appendix 7]
The controller
The storage device according to Appendix 6, further comprising an access processing execution management means for securing the buffer in the node for each partial area.
[Appendix 8]
The controller
The storage device according to Appendix 7, further comprising a data transfer control means for controlling data transfer between the transfer storage area corresponding to the partial area and the buffer corresponding to the partial area.
[Appendix 9]
The storage device according to Appendix 8, wherein the data transfer control means controls data transfer by the data transfer means between the buffer corresponding to the partial area and the partial transfer memory area corresponding to the partial area.
[Appendix 10]
The controller
The storage device according to Appendix 9, further comprising a mapping table for storing information that associates the area of the virtual storage medium with the area of the plurality of storage media.
[Appendix 11]
The controller
For each of the partial areas, the fourth address information indicating the partial transfer memory area, the identifier of the storage medium, the third address information indicating the transfer storage area, and the size corresponding to the partial area are obtained. The storage device according to Appendix 10, further comprising an access processing table for storing information on the transfer pair including the transfer pair.
[Appendix 12]
When the type of the access request is a read request, the controller transfers data from the storage medium area corresponding to the partial area to the buffer corresponding to the partial area for each partial area. After the data transfer from the area of the storage medium corresponding to the partial area to the buffer corresponding to the partial area is completed, the buffer corresponding to the partial area to the area corresponding to the partial area in the memory of the host. The storage device according to any one of Supplementary note 1 to 11, which is configured to start the data transfer of the above.
[Appendix 13]
When the type of the access request is a write request, the controller transfers data from the area corresponding to the partial area in the memory of the host to the buffer corresponding to the partial area for each partial area. After the data transfer from the area corresponding to the partial area in the memory of the host to the buffer corresponding to the partial area is completed, the storage medium corresponding to the partial area from the buffer corresponding to the partial area The storage device according to any one of Supplementary note 1 to 12, which is configured to start data transfer to an area.
[Appendix 14]
The storage device according to any one of Supplementary note 1 to 13, wherein the data transfer means is configured to perform RDMA (Remote Direct Memory Access).
[Appendix 15]
Between the node to which the controller is connected and the memory of the host, which provides access to the virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from the host via the network. It is a data transfer method of
The access target area on the virtual storage medium accessed by the access request is divided into partial areas.
Secure a buffer for each partial area
For each partial area, data transfer between the area of the storage medium corresponding to the partial area and the buffer corresponding to the partial area, and the buffer in the buffer corresponding to the partial area and the memory of the host. A data transfer method for transferring data to and from an area corresponding to a partial area.
[Appendix 16]
Computer,
A controller that provides access to a virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from a host via a network.
It functions as a data transfer means between the node to which the controller is connected and the memory of the host.
The controller divides the access target area on the virtual storage medium accessed by the access request into partial areas, secures a buffer for each partial area, and corresponds to the partial area for each partial area. Data transfer between the area of the storage medium and the buffer corresponding to the partial area, and the area corresponding to the partial area in the memory of the host and the buffer corresponding to the partial area by the data transfer means. A computer-readable recording medium that records programs that are configured to control data transfer between.

1 Host 10 Host memory 11 Host communication unit 12 Application 2 Target node 20 Target memory 200 Target buffer 21 Target communication unit 22 Controller 221 Access request reception unit 222 Mapping table 2222 Mapping entry 2222 Logical address 2223 Storage medium identifier 2224 Physical address 2225 Mapping size 223 Transfer storage area calculation unit 224 Transfer memory area calculation unit 225 Access processing table 2251 Access request entry 2252 Access type 2253 Transfer pair 2254 Memory address 2255 Storage identifier 2256 Storage medium address 2257 Transfer size 226 Access processing execution management unit 227 Data transfer control unit 23 Virtual storage medium 24 Storage medium 3 Network 41 Storage area 42 Mapping table 421 Logical address 422 Storage medium identifier 423 Physical address 43 Transfer storage area 51 Access target area 52 Transfer storage area 53 Transfer memory area 6 Storage device 61 Controller 62 Memory 621 Buffer 63 Virtual storage medium 64 Storage medium 7 Network 8 Host computer 81 Host memory 910 Arithmetic processing unit 920 Storage unit 930 Information processing device 940 Program

Claims (10)

A controller that provides access to a virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from a host via a network.
A data transfer means between the node to which the controller is connected and the memory of the host is provided.
The controller divides the access target area on the virtual storage medium accessed by the access request into partial areas, secures a buffer for each partial area, and corresponds to the partial area for each partial area. Data transfer between the area of the storage medium and the buffer corresponding to the partial area, and the area corresponding to the partial area in the memory of the host and the buffer corresponding to the partial area by the data transfer means. A storage device that is configured to control data transfer between. The storage device according to claim 1, wherein in the division, the controller divides the access target area into the partial area composed of at most one storage medium area. The storage device according to claim 2, wherein the controller is divided so that the number of the partial areas is minimized in the division. The controller
The type of the access request from the host, the first address information indicating the access target area, and the second address information indicating the transfer memory area on the memory for transmitting and receiving data between the access target area and the access target area. The storage device according to claim 3, further comprising an access request receiving means for acquiring and. The controller
The access target area is divided into the partial areas composed of at most one area of the storage medium, the size of each of the partial areas, the identifier of the storage medium corresponding to the respective partial areas, and the storage. The storage device according to claim 4, further comprising a transfer storage area calculation means for obtaining a third address information indicating a transfer storage area which is an area of a medium. The controller
The fifth aspect of claim 5 is provided with a transfer memory area calculation means for dividing the transfer memory area into partial transfer memory areas corresponding to the respective partial areas and obtaining a fourth address information indicating each of the partial transfer memory areas. Storage device. The controller
The storage device according to claim 6, further comprising an access processing execution management means for securing the buffer in the node for each partial area. The controller
The storage device according to claim 7, further comprising a data transfer control means for controlling data transfer between the transfer storage area corresponding to the partial area and the buffer corresponding to the partial area. Between the node to which the controller is connected and the memory of the host, which provides access to the virtual storage medium composed of areas of a plurality of storage media and receives an access request to the virtual storage medium from the host via the network. It is a data transfer method of
The access target area on the virtual storage medium accessed by the access request is divided into partial areas.
Secure a buffer for each partial area
For each partial area, data transfer between the area of the storage medium corresponding to the partial area and the buffer corresponding to the partial area, and the buffer in the buffer corresponding to the partial area and the memory of the host. A data transfer method for transferring data to and from an area corresponding to a partial area. For a computer having a virtual storage medium composed of multiple storage medium areas ,
The process of receiving an access request to the virtual storage medium from the host via the network, and
The process of dividing the access target area on the virtual storage medium accessed by the access request into partial areas, and
The process of securing a buffer for each partial area and
For each partial area, data transfer between the area of the storage medium corresponding to the partial area and the buffer corresponding to the partial area, and in the memory of the buffer corresponding to the partial area and the host. The process of transferring data to and from the area corresponding to the partial area, and
A program to make you do .

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