JP2018081346A - Storage device, storage system, storage control method, and storage control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve data transfer efficiency without providing a dedicated controller or the like in a system that provides a large-capacity logical disk with a plurality of storage devices.SOLUTION: One of a plurality of storage devices constituting a logical disk is provided with: data storage determination means for, by receiving an input/output command of a read that designates an address of a block of a logical disk (hereinafter referred to as a specified address) from a server device, determining whether the specified address is within the own device and which storage device has the address when being not in the own device; and command control means for a) transmitting a server device of the input/output command issuer and a direct transfer command of write designating the specified address to the storage device where the specified address exists, if it is determined that it does not within the own device, and b) transferring the data of the block of the specified address to the server device specified by the direct transfer command of write received from another storage device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a storage apparatus, a storage system, a storage control method, and a storage control program, and more particularly to control of a storage apparatus that configures one logical disk with a plurality of storage apparatuses.

  In scale-out storage or the like, a plurality of storage devices constitute one large logical disk, and the logical disk is allocated to the server device. In scale-out storage, a certain server device issues a data transfer command to a certain storage device, but an event occurs in which the data exists in another storage device. In this case, the storage apparatus that has received the data transfer command needs to transfer the data to the server apparatus after temporarily drawing data from another storage apparatus.

  FIG. 8 shows the situation at this time. In FIG. 8, the storage device 1 and the storage device 2 constitute a large logical disk. In FIG. 8, the server device 1 designates a certain logical block address in the logical disk and issues a read command to the storage 1, but the block is stored in the storage device 2. In this case, the storage apparatus 1 issues a read command to the storage apparatus 2. The data of the block is once transferred from the storage apparatus 2 to the storage apparatus 1 and then transferred from the storage apparatus 1 to the server apparatus 1.

  Patent Document 1 discloses an active-active virtual storage system that prevents inconsistencies between mirrors.

  Patent Document 2 discloses a disk array constituting a RAID (Redundant Array of Inexpensive Disks) in which a disk array controller, a disk device, and a host device are connected to one interface. This disk array performs communication between the disk array controller and the disk device, and between the disk array controller and the host device via one interface.

  When the disk array controller of this disk array receives a read host command from the host device, the disk array controller transmits a copy disk command to the disk device storing the read target data. When receiving the copy disk command, the disk device transmits data to the host device.

Japanese Patent Laid-Open No. 2006-024679 Japanese Patent Laid-Open No. 2004-280862

  As described above, when a storage apparatus that has received a data transfer command once pulls in data from another storage apparatus and then transfers the data to the server apparatus, useless transfer results in poor transfer efficiency.

  The above phenomenon does not occur if the server apparatus appropriately issues a data transfer command to the storage apparatus storing data. However, for this purpose, the server device needs to remember the information on the storage location of all data. Furthermore, when the storage device performs processing such as switching the data storage location between each other in consideration of performance, access frequency, etc., the information on the data storage location remembered by the server device is stored in the storage device. The process is complicated, such as the need to update each time.

  On the other hand, installing a dedicated controller as in the system disclosed in Patent Document 2 is costly and has problems in terms of performance / reliability. In particular, high cost becomes a big problem when complicated processing such as RAID is not assumed.

  It is an object of the present invention to provide a storage apparatus, a storage control method, and a storage control program that solve the above-described problems.

  A storage apparatus according to an embodiment of the present invention is one of a plurality of storage apparatuses that constitute a logical disk, and a read input in which an address (hereinafter, designated address) of the block of the logical disk is designated from a server apparatus. Data storage determining means for receiving an output command and determining whether the designated address is in the own device or in which storage device the specified address is not in the own device; and a) the determination is in the own device If not, the server device that issued the I / O command and the write direct transfer command designating the designated address are sent to the storage device where the designated address exists, and b) from the other storage device A command for transferring the block data at the specified address to the server device specified by the direct transfer command of the received write. It includes a command control means.

  The storage control method according to one embodiment of the present invention receives a read input / output command specifying a block address (hereinafter, designated address) in a logical disk composed of a plurality of storage devices from a server device. When the specified address is in a specific device (hereinafter referred to as own device) or not in the own device, it is determined in which storage device a) the determination is not in the own device. In this case, the server device that issued the input / output command and the direct transfer command of the write designating the designated address are transmitted to the storage device where the designated address exists, and b) received from the other storage device Data of the block at a specified address is transferred to the server device specified by the direct transfer command for writing.

  A storage control program according to an embodiment of the present invention receives a read input / output command designating a block address (hereinafter, designated address) of a logical disk composed of a plurality of computer devices from a server device, A data storage determination process for determining whether the designated address is in the own device or in the computer device if the designated address is not in the own device; a) if the determination is not in the own device, the input / output A direct transfer command of a write specifying the specified address and the server device that issued the command is transmitted to the computer device having the specified address; b) the direct transfer of the write received from the other computer device A command system that transfers data of the block at a specified address to the server device specified by an instruction. Executing process and, to the computer device.

  The storage device according to the present invention improves data transfer efficiency without providing a dedicated controller or the like in a system that provides a large capacity logical disk with a plurality of storage devices.

FIG. 1 is a diagram showing a configuration of a storage system 50 according to the first embodiment. FIG. 2 is a configuration diagram of the computer device 600. FIG. 3 is an operation flowchart of the storage system 50. FIG. 4 is a diagram illustrating a state of data transfer from the storage apparatus 20 to the server apparatus 10. FIG. 5 is a diagram illustrating a state of data transfer from the server apparatus 10 to the storage apparatus 20. FIG. 6 is a diagram illustrating the operation of the storage apparatus 20 according to the second embodiment. FIG. 7 is a diagram showing a configuration of the storage apparatus 20 according to the third embodiment. FIG. 8 is a diagram for explaining the background art.

<First Embodiment>
<Configuration>
FIG. 1 is a diagram showing a configuration of a storage system 50 according to the present embodiment. The storage system 50 is configured by connecting N (N is a natural number) server apparatuses 10 and M (M is a plurality) storage apparatuses 20 to a communication network 30. Each of the M storage devices 20 controls at least one disk device 24, and constitutes a logical disk 40 that is larger than the capacity of each disk device 24 as a whole. Here, the control refers to area management and input / output execution. The logical disk 40 is sometimes called a virtual disk.

  Each server device 10 performs input / output with respect to this logical disk 40. The server device 10 designates a logical block address in the logical disk 40 when executing input / output with respect to the logical disk 40. A logical block address in the logical disk 40 is converted into a block address of the disk device 24 controlled by any of the storage devices 20 constituting the logical disk 40.

  The storage device 20 includes a command control unit 21 and a data storage determination unit 23. The storage device 20 may include the disk device 24 in the device, or may be connected to the disk device 24 outside the device via a network in the data center or the like.

  The data storage determining unit 23 determines whether or not the block at the address specified by the server device 10 is in the disk device 24 controlled by the own device. If there is not, the data storage determination unit 23 determines which other storage device 20 the disk device 24 controlled by the block concerned has. Hereinafter, “a block at a certain address is in the disk device 24 controlled by a certain storage device 20” may be abbreviated as “a certain address is in a certain storage device 20”. .

  The command control unit 21 issues a direct data transfer command, which is a command requesting other storage devices 20 to transfer data directly to the server device 10. Further, when receiving a direct data transfer command from another storage device 20, the command control unit 21 also performs data transfer between the server device 10 and the disk device 24 controlled by the own device. The command control unit 21 receives an input / output command from the server device 10 and also performs data transfer between the server device 10 and the disk device 24 controlled by the own device.

  The server device 10 includes a command search unit 11 and a logical disk input / output unit 12.

  The logical disk input / output unit 12 performs input / output to / from the logical disk 40 in response to a request from a business processing program executed by the server device 10. The logical disk input / output unit 12 issues an input / output command designating a logical block address in the logical disk 40 to the storage apparatus 20.

  At this time, the logical disk input / output unit 12 selects the storage device 20 by, for example, round robin and issues an input / output command. Alternatively, the logical disk input / output unit 12 holds a correspondence table between the block address of the logical disk 40 having a long synchronization interval and the storage device 20 having the address, and selects the storage device 20 based on the table. An input / output command may be issued.

  The command search unit 11 searches for an input / output command issued by the own device based on the direct transfer command received from the storage device 20.

  Here, the command control unit 21 and the data storage determination unit 23 of the storage device 20 are configured by logic circuits.

  The storage device 20 may be realized by the computer device 600. FIG. 2 is a configuration diagram of the computer device 600. The computer device 600 includes a processor 610, a main storage unit 630, and an external storage device 620 that are connected to each other via a bus 640. The processor 610 reads / writes data from / to the main storage unit 630 and the external storage device 620 via the bus 640. Further, the processor 610 executes a program 650 stored in the main storage unit 630. Note that the program 650 is initially stored in the external storage device 620, and may be loaded from the external storage device 620 to the main storage unit 630 by the processor 610 when the computer device 600 is initially set.

  Here, the main storage unit 630 is a semiconductor memory device. The external storage device 620 is a storage device such as a disk device or a semiconductor storage device.

  The processor 610 functions as the command control unit 21 and the data storage determination unit 23 by executing the program 650. In other words, the processor 610 executes the program 650 to execute processing performed by the command control unit 21 and the data storage determination unit 23.

  The external storage device 620 may be used as the disk device 24.

  The command search unit 11 and the logical disk input / output unit 12 of the server device 10 are composed of logic circuits. The server device 10 may be realized by the computer device 600 like the storage device 20. In this case, the processor 610 functions as the command search unit 11 and the logical disk input / output unit 12 by executing the program 650. That is, the processor 610 executes the program 650 to execute processing performed by the command search unit 11 and the logical disk input / output unit 12.

<Operation>
Next, a state of data transfer between the server apparatus 10 and the storage apparatus 20 including direct data transfer will be described.

<1. Data transfer from the storage device 20 to the server device 10>
FIG. 3 is an operation flowchart of the storage system 50. FIG. 4 is a diagram illustrating a state of data transfer from the storage apparatus 20 to the server apparatus 10.

  In step S1 in FIG. 3, the server device 10, for example, the logical disk input / output unit 12 of the left server device 10 in FIG. 4 secures a buffer for storing read data, and the storage device 20, for example, in the left side in FIG. A read command (a in FIG. 4) is issued to the storage apparatus 20.

  Subsequently, the storage device 20 that has received the read command, for example, the storage device 20 on the left side of FIG. 4, executes steps S2 to S5.

  In step S2, the data storage determining unit 23 determines whether or not the block of the target address specified by the read command exists in the disk device 24 of the own device.

  In step S3, when the block of the read target address exists in the disk device 24 of the own device, the data storage determining unit 23 proceeds to step S4. If it does not exist, the data storage determining unit 23 identifies which other storage device 20 the disk device 24 of the target address has the block of the target address, and proceeds to step S5.

  The data storage determination unit 23 stores, for example, data indicating the block address range of the logical disk 40 corresponding to each storage device 20, and performs the above determination with reference to this range data. When there is a change, the range data is updated via, for example, a high-speed network different from the communication network 30 that connects the storage apparatuses 20. Alternatively, the data storage determination unit 23 may make an inquiry about the existence of a block address to the other storage apparatus 20 via the high-speed network described above.

  In step S4, the command control unit 21 transfers the data stored in the block in the disk device 24 of the own storage device 20 to the server device 10 that issued the read command, for example, the server device 10 on the left side of FIG. . Thereafter, the command control unit 21 proceeds to Step S12.

  In step S5, the command control unit 21 writes a write direct data transfer command (see FIG. 4) to the storage device 20, for example, the storage device 20 on the right side of FIG. Issue b). Thereafter, the command control unit 21 proceeds to Step S6. This command includes information such as the server device 10 that issued the read command, the target address specified by the read command, the data length, and the target logical number.

  Subsequently, the storage device 20 that has received the direct data transfer command, for example, the storage device 20 on the right side of FIG. 4, executes steps S6 to S8.

  In step S6, the command control unit 21 of the storage apparatus 20 that has received the direct data transfer command determines the received command. If the command is a direct data transfer command, the process proceeds to step S7. Transition to.

  In step S7, the command control unit 21 determines the server device 10 that issued the read command included in the received direct data transfer command, the target address, the data length, the target logical number, and the like specified by the read command. Create a write command. The command control unit 21 issues a write command (c in FIG. 4) to the server device 10 that issued the read command, for example, the server device 10 on the left side in FIG. 4, and proceeds to step S9.

  In step S8, the command control unit 21 performs command processing other than the direct data transfer command.

  Subsequently, the server device 10 that issued the read command, for example, the server device 10 on the left side of FIG. 4 executes steps S9 to S11.

  In step S9, the command search unit 11 of the server device 10 receives the write command from the storage device 20, and proceeds to step S10.

  In step S10, the command search unit 11 searches for a read command issued by the own device using the target address included in the received write command as a key. The command search unit 11 may use the data length, the target logical number, and other information in addition to the target address as a key for this read command search. When the read command is detected, the command search unit 11 allocates the buffer reserved for storing the read data in step S1 as a buffer for storing the write data transferred from the storage device 20, and proceeds to step S11. .

  In step S11, the logical disk input / output unit 12 performs direct write data transfer from the storage device 20 to the server device 10 (d in FIG. 4), and proceeds to step S12.

  In step S12, the logical disk input / output unit 12 completes the data transfer. Here, when the data transfer is performed by the direct data transfer command, the logical disk input / output unit 12 determines the completion of the read command issued in step S1 at the stage of returning the data transfer completion response to the storage device 20. .

<2. Data transfer from server device 10 to storage device 20>
FIG. 5 is a diagram illustrating a state of data transfer from the server apparatus 10 to the storage apparatus 20. As will be described below, the storage system 50 can efficiently execute data transfer in this direction.

  First, the logical disk input / output unit 12 of the server device 10, for example, the server device 10 on the left side of FIG. 5, stores the write data in a buffer, and writes a write command (for the storage device 20, for example, the storage device 20 on the left side of FIG. Issue a) in FIG.

  The data storage determining unit 23 of the storage device 20 that has received the write command, for example, the storage device 20 on the left side of FIG. 5, determines whether or not the block of the target address specified by the write command exists in the disk device 24 of the own device. Determine.

  If not present, the data storage determining unit 23 identifies in which other storage device 20 the disk device 24 of the write target address block exists. Then, the command control unit 21 reads the direct data transfer command (b in FIG. 5) to the storage device 20 in which the block of the target address specified by the write command exists, for example, the storage device 20 on the right side of FIG. Issue. This command includes information such as the server device 10 that issued the write command, the target address specified by the write command, the data length, and the target logical number.

  Subsequently, the command control unit 21 of the storage apparatus 20 that has received the direct data transfer command determines the received command. In the case of a direct data transfer command, the command control unit 21 determines the server device 10 that issued the write command included in the received direct data transfer command of the received read, the target address, data length, target logical number, etc. specified by the write command. Create a read command based on that. The command control unit 21 issues a read command (c in FIG. 5) to the server device 10 that issued the write command, for example, the server device 10 on the left side in FIG.

  The command search unit 11 of the server apparatus 10 receives the read command from the storage apparatus 20, and searches for the write command issued by the own apparatus using the target address included in the received read command as a key. The command search unit 11 may use the data length, the target logical number, and other information in addition to the target address as a key for the write command search. When the write command is detected, the command search unit 11 assigns the buffer specified by the write command as a buffer for direct read data transfer.

  Thereafter, the logical disk input / output unit 12 performs direct read data transfer from the server device 10 to the storage device 20 (d in FIG. 5).

<Effect>
The storage apparatus 20 according to the present embodiment improves the data transfer efficiency without providing a dedicated controller or the like in the storage system 50 that provides a large capacity logical disk 40 with a plurality of storage apparatuses 20. That is, the storage device 20 according to the present embodiment improves the overall performance of the server device 10 and the storage device 20 in scale-out storage.

  The reason is that even when the storage apparatus 20 having no designated address receives a read command, data is directly transferred from the storage apparatus 20 having the designated address to the server apparatus 10 side. This is because data transfer between the storage devices 20 can be eliminated by this direct transfer.

<Second Embodiment>
The command control unit 21 of the storage device 20 may perform data transfer through an optimum path in consideration of the load on the communication network 30. For example, as shown in FIG. 6, when the right switch path is heavily loaded, data transfer is performed using the left switch path.

  As a result, appropriate load distribution within the communication network 30 becomes possible.

<Third Embodiment>
FIG. 7 is a diagram showing a configuration of the storage apparatus 20 according to the third embodiment. The storage device 20 according to the present embodiment forms a logical disk 40 by a plurality of units. The storage apparatus 20 according to the present embodiment includes a data storage determination unit 23 and a command control unit 21. The storage device 20 further includes a storage device such as a disk device 24 or is connected to a storage device such as an external disk device 24.

  The data storage determining unit 23 receives a read I / O command specifying the block address (hereinafter designated address) of the logical disk 40 from the server device 10, and determines whether the specified address exists in the own device. If not, it is determined which storage device 20 is present. The storage device 20 and the server device 10 are connected via a network.

  If the determination is not in the own device, the command control unit 21 transmits the input / output command issuer server device 10 and the write direct transfer command designating the designated address to the storage device 20 in which the designated address exists. Further, the command control unit 21 transfers the data of the block at the designated address to the server device 10 designated by the write direct transfer command received from the other storage device 20.

  The storage apparatus 20 according to the present embodiment improves the data transfer efficiency without providing a dedicated controller or the like in the storage system 50 that provides a large capacity logical disk 40 with a plurality of storage apparatuses 20. That is, the storage device 20 according to the present embodiment improves the overall performance of the server device 10 and the storage device 20 in scale-out storage.

  The reason is that even when the storage apparatus 20 having no designated address receives a read command, data is directly transferred from the storage apparatus 20 having the designated address to the server apparatus 10 side. This is because data transfer between the storage devices 20 can be eliminated by this direct transfer.

  While the present invention has been described with reference to the embodiments, the present invention is not limited to the above 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.

10 Server device
11 Command search part
12 Logical disk I / O section
20 Storage device
21 Command control section
23 Data storage judgment section
24 disk units
30 communication network
40 logical disks
600 computer equipment
610 processor
620 External storage device
630 Main memory
640 bus
650 programs

Claims (10)

One of a plurality of storage devices constituting a logical disk,
When a read I / O command designating a logical disk block address (hereinafter designated address) is received from a server device, the storage device if the designated address is in the own device or not in the own device. Data storage judging means for judging whether or not the device is in the apparatus;
a) If the determination is not in the local device, the server device that issued the I / O command and the direct transfer command for the write designating the designated address are sent to the storage device where the designated address exists, b A storage apparatus comprising: command control means for transferring data of the block at a specified address to the server apparatus specified by the direct transfer instruction for a write received from another storage apparatus. The data storage determining means receives the input / output command of the write and makes the determination,
The command control means a) sends the read direct transfer command designating the designated address to the server device that issued the input / output command, and b) the direct transfer of the read received from the other storage device. The storage apparatus according to claim 1, wherein data is transferred from the server apparatus specified by an instruction to the block at a specified address.   When the command control means receives the direct transfer command transmitted from another storage device, the command control means transmits a data transfer command including the specified address to the server device specified by the direct transfer command. And b) data transfer between the server device specified by the direct transfer command transmitted from the other storage device upon receipt of an acknowledgment signal for the data transfer command and the block at the specified address. The storage apparatus according to claim 1, wherein A plurality of storage devices according to claim 3;
Logical disk input / output means for allocating an input / output buffer and issuing the input / output command; and when the data transfer command is received from the storage device, searches for the input / output command issued by the own device and A server system comprising: command search means for specifying, allocating the input / output buffer for the data transfer instruction, and returning the acknowledgment signal. A read I / O command specifying a block address (hereinafter designated address) in a logical disk composed of a plurality of storage devices is received from the server device, and the designated address is a certain device (hereinafter referred to as a specified device). If it is in the own device) or not in the own device, determine which storage device it is in,
a) If the determination is not in the local device, the server device that issued the I / O command and the direct transfer command for the write designating the designated address are sent to the storage device where the designated address exists, b A storage control method for transferring data of the block at a designated address to the server device designated by the direct transfer instruction of a write received from another storage device. Receiving the input / output command of the light, making the determination,
a) Sending a direct transfer command of the read designating the designated address to the server device that issued the input / output command, and b) Designating the direct transfer command of the read received from the other storage device 6. The storage control method according to claim 5, wherein data is transferred from the server device to the block at a specified address.   a) Upon receiving the direct transfer command transmitted from another storage device, the data transfer command including the specified address is transmitted to the server device specified by the direct transfer command, and b) the data An acknowledgment signal for a transfer command is received, and data transfer is performed between the server device specified by the direct transfer command transmitted from another storage device and a block at a specified address. The storage control method according to any one of claims 5 to 6. A read I / O command designating a block address (hereinafter designated address) of a logical disk composed of a plurality of computer devices is received from the server device, and whether the designated address exists in the own device or not A data storage determination process for determining which computer device is in the computer device if not,
a) If the determination is not in the local apparatus, the server apparatus that issued the input / output instruction and a direct transfer instruction for the write designating the designated address are transmitted to the computer apparatus in which the designated address exists, b Storage control for causing the computer apparatus to execute command control processing for transferring data of the block at the specified address to the server apparatus specified by the direct transfer instruction of the write received from the other computer apparatus program. The data storage determination process for receiving the input / output command of the write and performing the determination;
a) Sending a direct transfer command of the read designating the designated address to the server device that issued the input / output command, and b) Designating the direct transfer command of the read received from the other computer device 9. The storage control program according to claim 8, which causes the computer device to execute the command control processing for transferring data from a server device to the block at a specified address.   a) Upon receiving the direct transfer command transmitted from another computer device, the data transfer command including the specified address is transmitted to the server device specified by the direct transfer command, and b) the data The command control that receives an acknowledgment signal for a transfer command and executes data transfer between the server device specified by the direct transfer command transmitted from another computer device and a block at a specified address The storage control program according to any one of claims 8 to 9, which causes the computer apparatus to execute processing.

Images