JP2005004349A - Storage system, control method therefor and storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method for a storage system capable of making effective use of a storage resource which the other storage device has when the storage region of a certain storage device is short, and also to provide a storage system and a storage device. <P>SOLUTION: A first storage device determines whether data can be written to a first storage region when it receives a request for writing the data transmitted from an information processing device. When determining that the data can not be written, the first storage device requests information for determining whether a second storage region for storing the data can be secured to a second storage device. In response to the request, the second storage device transmits the information for determining whether or not the second storage region can be secured to the first storage device. The first storage device determines whether the second storage region can be secured based on the information. When determining that the second storage region can be secured, the first storage device transmits the data to the second storage device, and then the second storage device stores the data in the second storage region. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a storage system control method, a storage system, and a storage apparatus.
[0002]
[Prior art]
In today's globalized information society, the amount of data handled by information processing systems is increasing rapidly, and multiple storage devices are operated. For example, in data centers, storage areas provided to users are insufficient. Management is required so that there is no such thing.
[0003]
[Patent Document 1]
JP 2002-222061 A
[0004]
[Problems to be solved by the invention]
By the way, in a data center or the like, a plurality of storage devices are generally operated, and storage areas of these storage devices are generally managed individually for each storage device. For this reason, when the storage area of a certain storage apparatus is insufficient, the storage area is replenished by directly adding a physical disk or the like to the storage apparatus.
However, in a data center or the like, when a storage area of a certain storage apparatus is insufficient, another storage apparatus may have an excess storage area. Under such circumstances, it is difficult to say that the storage resources are used effectively when viewed as a whole of the plurality of storage apparatuses. For this reason, there is a demand for a mechanism for effectively utilizing the storage resources held by other storage apparatuses at a place where a plurality of storage apparatuses are operated.
[0005]
Therefore, a main object of the present invention is to provide a storage system control method, a storage system, and a storage apparatus that can effectively use storage resources held by other storage apparatuses.
[0006]
[Means for Solving the Problems]
A storage system control method that is an invention for achieving the above main object is as follows:
A first storage device that stores the data in a first storage area in response to a data write request transmitted from an information processing device that is communicably connected;
A second storage device communicably connected to the first storage device;
In a storage system control method comprising:
The first storage device receiving the data write request transmitted from the information processing device;
If the first storage device determines that the data cannot be written to the first storage area, the first storage device stores a second storage area for storing the data in the second storage device. Requesting information to determine whether it can be secured,
The second storage device transmits information for determining whether the second storage area can be secured to the first storage device;
The first storage device determines whether the second storage area can be secured based on the information transmitted from the second storage device; and
When the first storage device determines that the second storage area can be secured, the step of transmitting the data to the second storage device;
The second storage device stores the data transmitted from the first storage device in the second storage area; and
It is characterized by including.
[0007]
Here, the storage system is a system operated in, for example, a system center or a data center in a company. The information processing apparatus is a personal computer or mainframe computer that accesses the storage apparatus via a SAN or LAN. The first storage device and the second storage device are a disk array device or a semiconductor storage device that stores data in a storage area in response to an input / output request for data transmitted from the information processing device. . The first storage device and the second storage device are communicably connected via, for example, a SAN (Storage Area Network).
[0008]
The storage area for storing data is, for example, a physical volume that is a physical storage area provided by a physical disk (for example, a hard disk device, a flexible disk device, a semiconductor storage device, etc.), or a logical volume on a physical volume. For example, a logical volume which is a storage area set automatically. In the above, when data cannot be written to the storage area, for example, the storage area allocated to the company or organization has insufficient free space, or the physical disk or disk controller cannot operate. Say. In addition, as information for determining whether or not a storage area for storing data can be secured, for example, information on the free capacity of the storage area provided in the storage apparatus, and information on storage areas that can be lent to other storage apparatuses There is information.
[0009]
As described above, the storage system control method of the present invention makes it possible to secure an unused storage area in real time and store data in the storage area when data cannot be written.
In addition, the problems disclosed by the present application and the solutions thereof will be clarified by the embodiments of the present invention and the drawings.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
=== Example of Overall Configuration ===
<Storage system>
First, a hardware configuration of a storage system 800 described as an embodiment of the present invention will be described. FIG. 1 is a block diagram showing a hardware configuration of a storage system 800 according to the present embodiment.
The storage system 800 includes a plurality of storage devices such as the first storage device 100 and the second storage device 200. The storage system 800 is operated by, for example, a system center or a data center in a company.
[0011]
As shown in FIG. 1, the first storage device 100 of the storage system 800 is connected to one or a plurality of information processing devices 400 via a SAN 300. The information processing apparatus 400 is a computer that provides, for example, a bank automatic deposit and deposit service, an Internet homepage browsing service, and the like. The first storage device 100 functions as a device for storing data handled by the information processing device 400.
[0012]
The SAN 300 is a network that communicates according to, for example, a fiber channel protocol and connects the information processing apparatus 400 and the first storage apparatus 100. Communication between the information processing apparatus 400 and the first storage apparatus 100 performed via the SAN 300 is generally performed according to a fiber channel protocol. From the information processing apparatus 400, a block-unit data access request is transmitted to the first storage apparatus 100 according to the fiber channel protocol. Note that the information processing apparatus 400 and the first storage apparatus 100 do not necessarily have to be connected by a communication unit such as the SAN 300, and may be connected via a LAN or may be directly connected. It may be.
[0013]
A management computer 600 is connected to the first storage device 100 and the second storage device 200 of the storage system 800 via a LAN (Local Area Network) 500. The management computer 600 is a computer for operating and managing the storage system 800. The LAN 500 communicates according to a protocol such as TCP / IP (Transmission Control Protocol / Internet Protocol), for example, and is referred to as a first storage device 100 and a second storage device 200 (hereinafter referred to as “storage devices 100, 200”). ) And the management computer 600. Note that the storage apparatuses 100 and 200 and the management computer 600 do not necessarily have to be performed by communication means such as the LAN 500, but are SCSI (Small Computer Systems Interface) standard communication lines and bus lines, peer-to-peer, and the like. It may be connected with.
[0014]
The first storage device 100 is connected to the second storage device 200 via the SAN 700. Note that the first storage device 100 and the second storage device 200 do not necessarily have to be performed by communication means such as the SAN 300, but may be a Gigabit Ethernet (registered trademark), an ATM (Asynchronous Transfer Mode), a public line, or the like. It may be connected. Note that the SAN 300 and the SAN 700 may be SANs that are independent of each other, or may be configured to be communicably connected and the same SAN.
[0015]
<Storage device>
The first storage device 100 and the second storage device 200 (hereinafter referred to as “storage devices 100 and 200”) are, for example, a disk array device or a semiconductor storage device. The first storage device 100 performs data input / output processing in response to a data input / output request such as a data write request or data read request transmitted from the information processing device 400, for example.
[0016]
The second storage device 200 temporarily stores the write data when the first storage device 100 that has received the data write request transmitted from the information processing device 400 cannot write the write data. It has a function of providing a storage area for keeping it. Similar to the first storage apparatus 100, the second storage apparatus 200 receives data in response to data input / output requests transmitted from one or more information processing apparatuses 400 that are communicably connected. It may have a function of performing output processing.
[0017]
The storage apparatuses 100 and 200 include channel control units 110 and 210, shared memories 120 and 220, cache memories 130 and 230, disk control units 140 and 240, connection units 150 and 250, LU 160 and 260, a LAN adapter 170, and the like. Composed.
The channel controller 110 of the first storage device includes a communication interface for performing communication with the information processing device 400 and the second storage device 200, and is connected to the information processing device 400 and the second storage device 210. It has a function to exchange data input / output requests between them. The channel control unit 210 of the second storage device includes a communication interface for communicating with the first storage device 100, and exchanges data with the first storage device 100. It has a function.
[0018]
The disk control units 140 and 240 of the storage apparatuses 100 and 200 control the LUs 160 and 260. For example, the disk control unit 140 inputs / outputs data to / from the LU 160 according to a data write command or read command received from the information processing apparatus 400 by the channel control unit 110. Further, the data access request to the LU 160 by the logical address designation transmitted by the channel control unit 110 is converted into a data access request to the physical disk by the physical address designation.
[0019]
The disk control units 140 and 240 also provide a function of controlling a physical disk by a RAID system (for example, RAID 0, 1, 5). In this way, when the physical disks of the storage apparatuses 100 and 200 are managed by RAID, data is accessed according to a RAID (Redundant Array of Independent Drives) configuration (for example, RAID 0, 1, 5).
[0020]
The LUs 160 and 260 are storage areas that are logically set on physical storage areas provided by physical disks included in the storage apparatuses 100 and 200. The LUs 160 and 260 are storage areas for storing write data transmitted from the information processing apparatus 400. The storage area for storing data may be a part of the LUs 160 and 260, or a physical storage provided by a physical disk (for example, a hard disk device, a flexible disk device, a semiconductor storage device, etc.). It may be all or part of a physical volume that is an area.
[0021]
The connection units 150 and 250 of the storage apparatuses 100 and 200 connect the channel control units 110 and 210, the shared memories 120 and 220, the cache memories 130 and 230, and the disk control units 140 and 240 to each other. Data and commands are exchanged between the channel control units 110 and 210, the shared memories 120 and 220, the cache memories 130 and 230, and the disk control units 140 and 240 through the connection units 150 and 250. The connection units 150 and 250 are high-speed buses such as ultra-high-speed crossbar switches that perform data transmission by high-speed switching, for example.
[0022]
The LAN adapters 170 and 270 of the storage apparatuses 100 and 200 are, for example, NICs (Network Interface Cards), and provide a function for communicating with the management computer 600.
[0023]
The shared memories 120 and 220 and the cache memories 130 and 230 are storage memories shared by the channel controllers 110 and 210 and the disk controllers 140 and 240. The shared memories 120 and 220 are used for storing control information and commands, for example. The cache memories 130 and 230 are used to temporarily store data exchanged between the channel control units 110 and 210 and the disk control units 140 and 240, for example.
[0024]
In the present embodiment, it has been described that the shared memories 120 and 220 and the cache memories 130 and 230 are provided independently of the channel control units 110 and 210 and the disk control units 140 and 240. However, in the present embodiment, The present invention is not limited to this case, and the shared memories 120 and 220 or the cache memories 130 and 230 may be distributed and provided in the channel controllers 110 and 210 and the disk controllers 140 and 240, respectively. In this case, the connection units 150 and 250 connect the channel control units 110 and 210 and the disk control units 140 and 240 having distributed shared memory or cache memory to each other.
[0025]
<Management computer>
The management computer 600 is a computer for maintaining and managing the storage apparatuses 100 and 200 in the storage system 800. Note that the information processing apparatus 400 may have a function for maintaining and managing the storage apparatuses 100 and 200.
[0026]
The management computer 600 includes a CPU and a memory. The CPU of the management computer 600 is responsible for overall control of the management computer 600, and implements various functions and the like by executing programs stored in the memory.
[0027]
When the user or the like operates the management computer 600, for example, setting of the physical disk configuration, management and setting of the LUs 160 and 260 (capacity management, capacity expansion / reduction, allocation of the information processing apparatus 400, etc.), the storage apparatus 100, and the like. , 200 can be installed. Here, as the setting of the physical disk configuration, for example, the physical disk can be added or removed, the RAID configuration can be changed (change from RAID 1 to RAID 5, etc.), and the like. These settings are performed by a user or the like using a Web page provided by a Web server operating on the management computer 600 as a user interface.
[0028]
The management computer 600 can be built in the storage apparatuses 100 and 200 or can be externally attached. The management computer 600 may be a computer dedicated to maintenance and management of the storage apparatuses 100 and 200 and LUs 160 and 260, or a general-purpose computer having a maintenance and management function.
[0029]
<Information processing device>
The information processing apparatus 400 is a computer that includes a CPU (Central Processing Unit), a memory, and the like, similar to the management computer 600. The information processing apparatus 400 is, for example, a personal computer, a workstation, a mainframe computer, or the like. The CPU of the information processing apparatus 400 is responsible for overall control of the information processing apparatus 400, and implements various functions and the like by executing programs stored in the memory.
[0030]
The information processing apparatus 400 reads data stored in the LU 160 or sends data to the first storage apparatus 100 by sending data input / output requests such as data write requests and data read requests. Write data. FIG. 2 shows an example of a command format of a data input / output request such as a data write request or a data read request. In the header, the ID of the information processing apparatus 400 is set. In the port ID, the ID of the port for connecting to the logical volume 160 that is the processing target of the data input / output request is set. In the LUN (Logical Unit Number), an identifier of the logical volume 160 targeted by the data input / output request is set. The logical address of the data reading destination or writing destination is set as the address. In addition, the data length of the data to be read or written is set as the data length. When the data input / output request is a data write request, data to be written is added in addition to these.
[0031]
=== Example 1 ===
Next, processing of the storage system 800 when the information processing apparatus 400 transmits a data input / output request such as a data write request or a data read request to the first storage apparatus 100 will be described.
[0032]
<Process when receiving data write request>
FIG. 3 is a flowchart for explaining an example of a data write process of the storage system 800 when a data write request is transmitted from the information processing apparatus 400 to the first storage apparatus 100.
[0033]
When the channel control unit 110 of the first storage device 100 receives a data write request transmitted from the information processing device 400 (S300), the channel control unit 110 writes data to the LU 160 specified by the data write command. It is determined whether or not it can be performed (S301). This determination is made, for example, by referring to the free capacity management table 2200 of the logical volume 160 of the first storage device 100 shown in FIG. 5 and the free capacity of the LU 160 specified by the data write command and the data of the data write command. This is done by comparing the length. The logical volume free capacity management table 2200 is created, for example, when the channel control unit 110 receives a free capacity report of each LU 160 from the disk control unit 140 in real time. The logical volume free space management table 2200 may be stored in the shared memory 120 or in the LU 160.
[0034]
When the free capacity of the LU 160 specified by the data write command and the data length of the data write command are compared with reference to the free capacity management table 2200 of the logical volume, the free capacity of the LU is larger than the data length It is determined that data can be written to the. On the other hand, when the free space of the LU is smaller than the data length, it is determined that data cannot be written. This determination may be performed by the channel control unit 110 as described above, or may be performed by the disk control unit 140.
[0035]
As a result of the determination in (S301), when it is determined that data can be written (S301; Yes), the channel control unit 110 writes the received data write command to the shared memory 120 and from the information processing apparatus 400. The received data to be written (hereinafter referred to as “write data”) is written into the cache memory 130. The disk control unit 140 monitors the contents of the shared memory 120 in real time. When the disk controller 140 detects that a data write command is written in the shared memory 120 by this monitoring, the disk controller 140 reads the write data from the cache memory 130, and based on the LU 160 and logical address specified in the data write command. The write data is written to the LU 160 (S302).
[0036]
When the data writing to the designated LU 160 is completed, the disk control unit 140 notifies the channel control unit 110 to that effect. The channel control unit 110 that has received the notification actually stores the location (for example, LUN, logical address, and data length) designated by the data write command transmitted from the information processing apparatus 400 and the write data. The location (for example, storage device, LUN and logical address) is recorded in the data management table 2100 stored in the LU 160, the shared memory 120, etc. (S303).
[0037]
FIG. 4 shows an example of the data management table 2100. As shown in FIG. 4, the data management table 2100 includes data management addresses such as LUNs, logical addresses, and data lengths specified by data write commands transmitted from the information processing apparatus 400, and the information processing apparatus 400. The storage device that actually stores the write data transmitted from the storage device, the LUN, and the actual address of the data such as the logical address are recorded.
[0038]
Next, the channel control unit 110 of the first storage device 100 notifies the information processing device 400 of a write completion report (S304), and ends the data write processing. The writing completion report to the information processing apparatus 400 may be performed in synchronization with the data writing operation to the LU 160 as described above, but is performed asynchronously with the actual data writing operation to the LU 160. It is good.
[0039]
On the other hand, as a result of the determination in (S301), when it is determined that data cannot be written (S301; No), the disk control unit 140 notifies the channel control unit 110 accordingly. The channel controller 110 that has received the notification stores data in the storage device (in this embodiment, the second storage device 200) that is communicably connected to the first storage device 100. Information for determining whether or not the storage area can be secured is requested (S305). This request for information is made when the channel controller 110 determines that data cannot be written because the disk controller 140 cannot operate, or when the disk controller 140 uses a data write command because the physical disk cannot operate. This may also be performed when it is determined that data cannot be written to the designated LU 160.
[0040]
When the channel controller 210 of the second storage device 200 receives a request for information from the first storage device 100 to determine whether a storage area for storing data can be secured (S306), Information for determining whether or not a storage area for storing data can be secured in the storage apparatus 100 is transmitted (S307). This information may be, for example, the logical volume management table 2300 of the second storage device 200 shown in FIG. 6 or the lentable logical volume management table 2400 shown in FIG. By referring to these tables by the first storage device 100, it is possible to determine whether or not a storage area for storing data can be secured.
[0041]
As shown in FIG. 6, the logical volume management table 2300 records the usage status, free capacity, access frequency, etc. of each LU 260 in the second storage device 200, but is not limited to these. The degree of data importance, the ratio of the used area to the storage capacity of the LU 260 (utilization rate), and the like may be recorded. In the rentable logical volume management table 2400 shown in FIG. 7, a storage area that the second storage apparatus 200 determines to lend the LU 260, for example, an unused storage area or a lending permission from a user or the like in advance is obtained. Information such as storage area is recorded. These tables may be created when there is a request for information for determining whether or not a storage area for storing data can be secured from the first storage device 100, but in advance the shared memory 220 Or LU 260 or the like.
[0042]
When the channel controller 110 of the first storage device 100 receives information for determining whether or not a storage area for storing data can be secured from the second storage device 200 (S308), the first storage device The channel controller 110 determines whether the storage area can be secured based on the information (S309). This determination is based on whether the usage status of the LU 260 is “unused” or the free capacity is larger than the size of the write data transmitted from the information processing device 400 when the logical volume management table 2300 is transmitted. This is performed by determining whether the access frequency of the LU 260 is “low”. Further, when the rentable logical volume management table 2400 is transmitted, it is determined by determining whether or not the rentable storage area is larger than the size of the write data transmitted from the information processing apparatus 400.
[0043]
As a result of the determination in (S309), when it is determined that a storage area for storing write data cannot be secured (S309; No), the information processing apparatus 400 is notified that data cannot be written (S317). ) Notifies the management computer 600 that there is no free space in the LU 160 (S318), and ends the data writing process. On the other hand, as a result of the determination in (S309), if it is determined that a storage area for storing the write data can be secured (S309; Yes), the channel control unit 110 performs the write command and write operation specifying the storage area. Data (data write request) is transmitted to the second storage device 200 having the storage area (S310).
[0044]
When receiving the data write request transmitted from the first storage device 100 (S311), the channel control unit 210 of the second storage device 200 writes the received data write command to the shared memory 220, and Write data received from one storage apparatus 100 is written to the cache memory 230.
[0045]
When the disk controller 240 of the second storage device 200 detects that a data write command has been written to the shared memory 220, it reads the write data from the cache memory 230. Then, the write data is written into the storage area designated by the data write command (S312). When the writing of data to the designated storage area is completed, the disk control unit 240 notifies the channel control unit 210 to that effect. The channel control unit 210 that has received the notification notifies the first storage device 100 of a data write completion report (S313).
[0046]
When the channel controller 110 of the first storage device 100 receives the data write completion report notification from the second storage device 200 (S314), it is designated by the data write command sent from the information processing device 400. Data management stored in the LU 160, the shared memory 120, etc., such as the location (for example, LUN, logical address and data length), the location (for example, storage device, LUN and logical address) where the write data is actually stored It records in the table 2100 (S315). By this recording, the first storage device 100 can grasp which LU of each storage device stores each data.
[0047]
When the channel controller 110 of the first storage device 100 receives the notification of the data write completion report from the second storage device 200 (S314), it notifies the information processing device 400 of the data write completion report (S316). The management computer 600 is notified that data cannot be written to the LU 160 (S318). Then, the storage system 800 ends the data writing process.
[0048]
As described above, when data cannot be written to the LU 160 due to a problem such as a failure of the physical disk or the disk control unit 140 or a capacity shortage of the LU 160, the operation of the information processing apparatus 400 is not interrupted. The data is stored by borrowing the storage area held by the storage device. Therefore, the storage resources existing in the storage system 800 can be used effectively. In the embodiment of the present invention, it goes without saying that data can be stored not only in the storage area that can be directly accessed by the information processing apparatus 400 but also in a storage area that cannot be directly accessed.
[0049]
Further, by notifying the management computer 600 that data cannot be written to the LU 160 from the first storage device 100 (S316), an operator or the like who manages the storage system 800 can detect a failure of the physical disk or the disk control unit 140. It is possible to know that data cannot be written to the LU 160 due to a problem such as insufficient capacity of the LU 160. The channel control unit 110 may notify the management computer 600 that data cannot be written to the LU 160 (S316), and may also notify the data management address and real address information of the data management table 2100. As a result, the management computer 600 can know where the data that could not be written to the LU 160 is stored, and after solving problems such as a failure of the physical disk or the disk control unit 140 and insufficient capacity of the LU 160. The operator or the like can cause the storage system 800 to execute a data write-back process to be described later for each data.
[0050]
In the embodiment described above, the first storage apparatus 100 stores data from the second storage apparatus 200 when data cannot be written to the LU 160 specified by the data write command transmitted from the information processing apparatus 400. Although the area is borrowed and the data is written, the first storage apparatus 100 may borrow the storage area of the storage apparatus and write the data.
[0051]
<Process when receiving data read request>
FIG. 8 is a flowchart for explaining an example of data read processing of the storage system 800 when a data read request is transmitted from the information processing device 400 to the first storage device 100.
[0052]
When the channel control unit 110 of the first storage device 100 receives a data read request transmitted from the information processing device 400 (S800), the LUN specified by the data read command is referred to the data management table 2100. And the logical address is converted into the LUN and logical address recorded in the real address of the data. Then, it is determined whether or not the storage device recorded at the real address of the data is the first storage device 100 (S802). If it is determined that this is the first storage device 100 (S802; Yes), a read command for the converted data is sent to the disk controller 140. Note that the transmission of the converted data read command from the channel control unit 110 to the disk control unit 140 may be performed via the shared memory 120.
[0053]
When the disk control unit 140 receives the read command of the converted data from the channel control unit 110, the disk control unit 140 reads the data to be read (hereinafter referred to as “read data”) based on the LUN and logical address specified by the converted data read command. Is read from the LU 160 (S803). Then, the read data is written into the cache memory 130. When the data transfer to the cache memory 130 is completed, the disk control unit 140 notifies the channel control unit 110 to that effect. The channel control unit 110 that has received the notification transmits the read data stored in the cache memory 130 to the information processing apparatus 400 (S804), and ends the data read process.
[0054]
If it is determined by (S802) that the storage device 100 is not the first storage device 100 (S802; No), the channel control unit 110 of the first storage device 100 stores the storage device recorded at the real address of the data. In this embodiment, a read request for the converted data is transmitted to the second storage apparatus 200 (S805).
[0055]
When the channel controller 210 of the second storage device 200 receives a data read request from the first storage device 100 (S806), it sends this data read command to the disk controller 240. When the disk control unit 240 receives a data read command from the channel control unit 210, the disk control unit 240 reads the read data from the LU 260 based on the command and writes the read data to the cache memory 230. When the data transfer to the cache memory 230 is completed, the disk control unit 240 notifies the channel control unit 210 to that effect. Upon receiving the notification, the channel control unit 210 transmits the read data stored in the cache memory 230 to the first storage device 100 (S807).
[0056]
When the channel control unit 110 of the first storage device 100 receives the read data from the second storage device 200 (S808), it transmits the read data to the information processing device 400 (S804), and ends the data read processing. To do.
[0057]
<Data write-back processing>
Next, a description will be given of the data write-back processing of the storage system 800 that is performed when problems such as a lack of free space in the LU 160 and a failure of the physical disk or the disk control unit 140 are solved.
The data write-back process is automatically performed when the first storage device 100 determines that the data written to the second storage device 200 can be written back. Specifically, when the user or the like deletes data stored in the LU 160, the free capacity of the LU 160 becomes larger than the size of data written in the second storage device, or the first storage device This process is started when the LU 160 is increased to 100 or when the physical disk or the disk control unit 140 is repaired or replaced. The data write-back process of the storage system 800 will be described below.
[0058]
FIG. 9 is a flowchart for explaining an example of data write-back processing in the storage system 800. When the disk control unit 140 of the first storage device 100 starts the data write-back process, the disk control unit 140 refers to the data management table 2100 to write back data for requesting the return of data stored in the second storage device 200. A request is created and transmitted to the second storage device 200 (S900). When the channel controller 210 of the second storage device 200 receives a data write-back request from the first storage device 100 (S901), the channel controller 210 sends the received data write-back command to the disk controller 240. Send it out. Note that transmission of a data write-back command from the channel control unit 210 to the disk control unit 240 may be performed via the shared memory 220.
[0059]
When receiving a data write-back command from the channel control unit 210, the disk control unit 240 reads data to be written back (hereinafter referred to as “write-back data”) specified in the command from the LU 260 (S902). ) The read data is written into the cache memory 230. When the data transfer to the cache memory 230 is completed, the disk control unit 240 notifies the channel control unit 210 to that effect. Upon receiving the notification, the channel control unit 210 transmits the write-back data stored in the cache memory 230 to the first storage device 100 together with the data write-back command (S903).
[0060]
When the channel controller 110 of the first storage device 100 receives a data write-back command and write-back data from the second storage device 200 (S904), it creates a data write command specifying the LUN and address. In the LUN of this data write command, the identifier of the LU 160 to which the write-back data was supposed to be written or the identifier of the increased LU 160 is designated. The logical address of the unused storage area is designated as the address of the data write command. Note that the LUN specified by the data write command refers to the data management table 2100, the storage device that sent the data write-back command, the LUN and logical address specified by the data write-back command, etc. To be determined.
[0061]
Next, the channel control unit 110 writes the created data write command to the shared memory 120 and writes the write-back data to the cache memory 130. When the disk control unit 140 of the first storage device 100 detects that a data write command is written in the shared memory 120, it reads the write-back data from the cache memory 130. Then, the disk control unit 140 writes the write-back data into the LU 160 (S905).
[0062]
When the write back of the write-back data to the LU 160 specified by the data write command is completed, the disk control unit 240 notifies the channel control unit 110 that the data write has been completed. Receiving the notification, the channel control unit 110 records the location where the write-back data is stored in the data management table 2100 (S906). Specifically, the identifier of the storage device of the real address of the data in the data management table 2100 is converted into the identifier of the first storage device, and the LUN and logical address of the real address of the data are written by the channel control unit 110. Convert to LUN and logical address specified in command.
[0063]
Next, the channel control unit 110 creates a write-back data deletion command based on the LUN and logical address specified in the data write-back command, and deletes the write-back data from the second storage device 200. A request is made (S907). When the channel controller 210 of the second storage device 200 receives the write-back data deletion request (S908), it sends this data deletion command to the disk controller 240. Upon receiving a data deletion command from the channel control unit 210, the disk control unit 240 deletes data from the LU 260 based on the command (S909). When the data deletion is completed, the disk control unit 240 notifies the channel control unit 210 to that effect. Upon receiving the notification, the channel control unit 210 transmits a data deletion completion report to the first storage device 100 (S910).
[0064]
When the channel controller 210 of the first storage device 100 receives a data completion report from the second storage device 200 (S911), it notifies the management computer 800 of a data write-back completion report (S912). Then, the data write-back process is terminated. Note that the channel control unit 110 may notify the management computer 600 of a data write-back completion report (S912), and may notify the data management address and real address information of the data management table 2100.
[0065]
As described above, when the first storage apparatus 100 determines that the data written in the second storage apparatus 200 can be written back, the data write-back process is started. As a result, the operator or the like does not need to perform a complicated operation such as a data write-back operation after solving the problem such as the failure of the physical disk or the disk control unit 140 or the capacity shortage of the LU 160.
[0066]
=== Other Embodiments ===
In the above-described embodiment, the data writing process, the data writing back process, and the data reading process in the storage system 800 including the two storage apparatuses 100 and 200 have been described. The present invention can also be applied to a storage system 800 including a single storage device, and the same effects as described above can be obtained.
[0067]
FIG. 10 is a block diagram showing the overall configuration of a storage system 800 described as another embodiment. One or a plurality of information processing devices 400 are connected to the first storage device 1100 of the storage system 800 via the SAN 300, and the second storage device 1200 is connected to the first storage device 1100 via the SAN 700. In addition, a third storage device 1300 is connected to the second storage device 1200 via a SAN 710. A management computer 600 is connected to the first to third storage apparatuses 1100, 1200, 1300 via the LAN 500.
[0068]
FIG. 11 is a block diagram showing the overall configuration of a storage system 800 described as another embodiment. One or a plurality of information processing devices 400 are connected to the first storage device 1100 of the storage system 800 via the SAN 300, and the second storage device 1200, the third storage device 1300, And the fourth storage device 1400 is connected. A management computer 600 is connected to the first to fourth storage apparatuses 1100, 1200, 1300, 1400 via the LAN 500.
[0069]
=== Application Examples ===
The control method such as data write processing and data write back processing of the storage system of the present invention can be performed by, for example, storage areas of other storage apparatuses when data cannot be written to the storage areas allocated to each company. It can be applied to a service for renting and temporarily storing data. The storage area rental service will be described in detail below with reference to FIGS. 1 and 12 to 15.
[0070]
FIG. 12 shows an example of a table 2100 that manages the free capacity of the logical volume 160 of the storage apparatus 100. As shown in FIG. 12, each LU 160 of the first storage device 100 is assigned to each user (company). In the present embodiment, “unusable” is recorded in the usage status of LU5 (160) of company D because there is no free space in LU5 (160). In addition, in the usage status of LU6 (160) of company E, “unusable” is recorded because the disk controller 140 cannot be accessed due to some failure.
[0071]
When a data write request for company A is transmitted from the information processing apparatus 400, the first storage apparatus 100 determines that data can be written with reference to the free capacity management table 2500 of the logical volume. Then, the first storage device 100 writes the data of the company A into LU1 (LU160). On the other hand, when a data write request for company D or company E is transmitted from the information processing apparatus 400, the first storage apparatus 100 refers to the free capacity management table 2500 of the logical volume and cannot write data. to decide. Then, the first storage device 100 requests information for determining whether a storage area for storing data in the second storage device 200 can be secured.
[0072]
Upon receiving this request for information, the second storage device 200 receives information such as the logical volume management table 2600 shown in FIG. 13 and the rentable logical volume management table 2700 shown in FIG. Send to. The first storage device 100 that has received this information selects the logical volume to be borrowed by referring to this information. Note that the LU 260 to be borrowed is selected based on, for example, conditions specified in advance by the user or the like (for example, a usable area or a usage status).
[0073]
The first storage device 100 transmits a data write request to the second storage device 200 by designating the selected LU 260 and logical address. Receiving this data write request, the second storage device 200 writes the write data to the LU 260 specified by the data write command, and notifies the first storage device 100 of a data write completion report.
[0074]
Upon receiving the data write completion report notification, the first storage device 100 records the data management address and data real address in the data management table 2100 and notifies the information processing device 400 of the data write completion report. Further, the first storage device 100 notifies the management computer 600 that the free space is insufficient in the LU 5 (160), and the company D allocates the storage area of the LU 3 (260) of the second storage device 200. Notify that 300MB is borrowed. Receiving these notifications, the management computer 600 displays these on the display. Further, it is recorded in the storage area borrowing information 2800 shown in FIG. 15 that the company D has borrowed 300 MB of the storage area of the LU 3 (260) of the second storage device 200. In this storage area borrowing information, information on the borrower of the storage area, borrowing destination information (storage device, LUN, etc.), used area, rental fee, and the like are recorded. The rental fee is calculated based on, for example, the usage area, the number of days used, the performance of the storage device, the line speed, and the like.
[0075]
As described above, the control method of the storage system 800 of the present invention can be applied to a service that rents a storage area of another storage apparatus and temporarily stores data.
[0076]
In the above description, the storage area lending / borrowing between the plurality of storage apparatuses 100 and 200 has been described. However, the storage area lending / borrowing may be performed within the same storage apparatus. A specific description will be given below.
[0077]
When a data write request to the LU2 (160) of company B is transmitted from the information processing apparatus 400, the first storage apparatus 100 cannot write data by referring to the free capacity management table 2500 of the logical volume. to decide. Before the first storage apparatus 100 requests information for determining whether or not a storage area for storing data in another storage apparatus can be secured, the first storage apparatus 100 It is determined whether a storage area for storing data in the storage apparatus 100 can be secured.
[0078]
This determination is made by referring to the logical volume management table 2300 and the rentable logical volume management table 2400 of the first storage device 100, or whether there is an unused LU 160, or the first storage device 100. Whether or not there is a rentable storage area is checked, and the LU 160 to be borrowed by the company B is selected. The selection of the LU 160 to be borrowed may be performed based on, for example, a condition (for example, an area that can be used or a usage situation) designated in advance by a user or the like.
[0079]
When the first storage apparatus 100 determines that a storage area for storing data can be secured, the first storage apparatus 100 writes the data in the storage area (for example, LU4 (160)). Then, the management address of data and the actual address of data in the data management table 2100 are recorded, and a data write completion report is notified to the information processing apparatus 400. In addition, the first storage device 100 notifies the management computer 600 that LU2 (160) has insufficient free space, and company B allocates the storage area of LU4 (160) of the first storage device 100. Notify that 49000MB is borrowed. Receiving these notifications, the management computer 600 displays these on the display. Further, it is recorded in the storage area borrowing information 2800 shown in FIG. 15 that the company B has borrowed 49000 MB of the storage area of the LU 4 (160) of the first storage device 100.
[0080]
On the other hand, if it is determined that a storage area for storing data cannot be secured, the first storage apparatus 100 secures a storage area for storing data in the second storage apparatus 200 as described above. Information for determining whether or not it is possible is requested, and the same processing is performed.
[0081]
Although the present embodiment has been described above, the above examples are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.
[0082]
【The invention's effect】
According to the present invention, the present invention can provide a storage system control method, a storage system, and a storage apparatus that can effectively use storage resources held by a plurality of storage apparatuses.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a hardware configuration of a storage system according to the present embodiment.
FIG. 2 is a diagram showing an example of a command format of a data input / output request according to the present embodiment.
FIG. 3 is a flowchart for explaining an example of data write processing of the storage system according to the embodiment;
FIG. 4 is a diagram showing an example of a data management table according to the present embodiment.
FIG. 5 is a diagram showing an example of a free capacity management table of a logical volume of the first storage device according to the embodiment.
FIG. 6 is a diagram showing an example of a logical volume management table of the second storage device according to the embodiment.
FIG. 7 is a diagram showing an example of a lendable logical volume management table according to the present embodiment.
FIG. 8 is a flowchart for explaining an example of data read processing of the storage system according to the embodiment;
FIG. 9 is a flowchart for explaining an example of data write-back processing in the storage system according to the embodiment;
FIG. 10 is a block diagram showing an example of the overall configuration of a storage system according to the present embodiment.
FIG. 11 is a block diagram showing an example of the overall configuration of a storage system according to the present embodiment.
FIG. 12 is a diagram showing an example of the free capacity management table of the logical volume of the first storage device according to the embodiment.
FIG. 13 is a diagram showing an example of a logical volume management table of the second storage device according to the embodiment.
FIG. 14 is a diagram showing an example of a rentable logical volume management table according to the present embodiment.
FIG. 15 is a diagram showing an example of storage area borrowing information according to the present embodiment.
[Explanation of symbols]
100, 1100 First storage device
200, 1200 Second storage device
110, 210 channel control unit
120,220 shared memory
130,230 cache memory
140,240 disk controller
150,250 connections
160, 260 Logical volume (LU)
170,270 LAN adapter
300, 700, 710, 720 SAN
400 Information processing device
500 LAN
600 Management computer
800 storage system
1300 Third storage device
1400 Fourth storage device

Claims (5)

A first storage device that stores the data in a first storage area in response to a data write request transmitted from an information processing device that is communicably connected;
A second storage device communicably connected to the first storage device;
In a storage system control method comprising:
The first storage device receiving the data write request transmitted from the information processing device;
If the first storage device determines that the data cannot be written to the first storage area, the first storage device stores a second storage area for storing the data in the second storage device. Requesting information to determine whether it can be secured,
The second storage device transmits information for determining whether the second storage area can be secured to the first storage device;
The first storage device determines whether the second storage area can be secured based on the information transmitted from the second storage device; and
When the first storage device determines that the second storage area can be secured, the step of transmitting the data to the second storage device;
The second storage device stores the data transmitted from the first storage device in the second storage area; and
A method for controlling a storage system. The storage system control method according to claim 1,
A method for controlling a storage system, comprising: storing information indicating that the data transmitted from the information processing apparatus exists in the second storage area of the second storage apparatus. The storage system control method according to claim 1,
When the first storage device determines that the data stored in the second storage area of the second storage device can be written to the first storage area, the first storage device stores the data in the second storage device. Sending a data write-back request to request data write-back;
The second storage device, when receiving a data write-back request from the first storage device, sending the data to the first storage device;
The first storage device, when receiving the data from the second storage device, storing the data in the first storage area;
A method for controlling a storage system. A first storage device that stores the data in a first storage area in response to a data write request transmitted from an information processing device that is communicably connected;
A second storage device communicably connected to the first storage device;
In a storage system comprising
Means for the first storage device to receive the data write request transmitted from the information processing device;
If the first storage device determines that the data cannot be written to the first storage area, the first storage device stores a second storage area for storing the data in the second storage device. A means of requesting information to determine whether it can be secured,
The second storage device transmits information for determining whether the second storage area can be secured to the first storage device;
The first storage device determines whether the second storage area can be secured based on the information transmitted from the second storage device;
Means for transmitting the data to the second storage device when the first storage device determines that the second storage area can be secured;
The second storage device stores the data transmitted from the first storage device in the second storage area;
A storage system comprising: Means for storing the data in the first storage area in response to a data write request transmitted from the information processing apparatus connected to be communicable;
A communication means for communicably connecting to the second storage device;
In a storage device comprising:
Means for receiving the data write request transmitted from the information processing apparatus;
When it is determined that the data cannot be written to the first storage area, it is determined whether or not a second storage area for storing the data can be secured in the second storage device. Means for requesting information on,
Means for determining whether the second storage area can be secured based on the information transmitted from the second storage device;
Means for transmitting the data to the second storage device in order to store the data in the second storage region of the second storage device when it is determined that the second storage region can be secured When,
A storage apparatus comprising:

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