JP2003196140A - Exclusive control device and exclusive control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a computer system and exclusive control method allowing a computer to exclusively access a storage area regardless whether a storage device has an exclusive control function or not by preventing the deterioration in network performance by an exclusive control. <P>SOLUTION: In the computer system comprising a plurality of computers connected to an external storage device for storing shared data through a relay device, the exclusive control is executed in a device other than the storage device. Concretely, the relay device having a virtualization processing function executes the exclusive control. The relay device has the information showing whether the storage area on the storage device is an exclusive access area or not, and the relay device judges whether an access request received from the computer is the access request to the exclusive access area or not, and executes the exclusive control when it is the access request to the exclusive access area. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of computers each independently executing arithmetic processing, an external storage device storing shared data accessed from the plurality of computers, and an external storage device from each of the plurality of computers. The present invention relates to a computer system having a relay device that receives an access request for data stored in a storage device and relays the access request to an external storage device.

[0002]

2. Description of the Related Art As the amount of data used in a computer increases, a technique for connecting a plurality of storage devices to the outside of the computer via a network is used. According to this technique, a plurality of computers connected to the network can share and use the data stored in the storage device connected to the network. When sharing the data stored in the storage device among multiple computers, while data is being accessed by one computer, the data can be transferred by a technique such as exclusive control that limits access to the data from other computers. We need to ensure consistency. As one of the technologies that enables exclusive control, there is exclusive control using the Reserve / Release command of the SCSI protocol described in Non-Patent Document 1. This technology allows exclusive control in logical block address units.

[0003]

[Non-Patent Document 1] “Scagy-3 Primary Command (S
CSI-3 Primary Commands) ”, [online], March 28, 1997
Japan-American National Standards Institute, p.7
0-72 p.88-93, [Search date: September 20, 2002], Internet <URL: ftp: //ftp.t10.org/t10/drafts/spc/spc-r11a.p
df>

[0004]

Exclusive control is executed by a storage device. A right to exclusively access a storage area (hereinafter, referred to as a shared area) of a storage device that stores data shared between a plurality of computers (hereinafter, referred to as shared data) (hereinafter, an exclusive access right, Call)
If there is a computer that has acquired the access request, when another computer issues an access request to the shared area (hereinafter referred to as the exclusive access area) that is the target of the exclusive access right, this access request is rejected. To be done. At this time, the storage device sends an access refusal response to the computer.
When the computer that receives the access denial response reissues the access request, the access denial response and the access request frequently occur between the storage device and the computer, and the bandwidth of the network to which the storage device is connected is consumed, resulting in network performance. Is reduced. As a result, not only the performance of the network between the computer that has acquired the exclusive access right and the storage device is degraded, but also the performance of the network between the other computer that accesses the area other than the exclusive access area and the storage device is degraded.

The exclusive control described in Non-Patent Document 1 is not designated as an essential function of the SCSI protocol. Therefore, there is a storage device that does not have the exclusive control function, and the computer system may not be able to perform the exclusive control.

Further, in a computer system in which a plurality of storage devices are connected to a network, a storage device having an exclusive control function and a storage device not having the exclusive control function may coexist in the computer system. In this case, in order to execute the exclusive control in the computer system, it is necessary to select the storage device having the exclusive control function, but the selection is difficult.

In a computer system having a virtualization function of providing a virtual storage area (hereinafter referred to as virtual volume) to a computer, the storage area of the storage device is virtualized, so The features that it has are hidden.
Therefore, it is difficult to configure the virtual volume only from the storage area of the storage device having the exclusive control function and provide it to the computer.

An object of the present invention is to prevent a decrease in network performance due to exclusive control and to allow a computer to access a storage area exclusively regardless of whether or not the storage device has an exclusive control function. It is to provide a system and an exclusive control method.

[0009]

According to the present invention, the exclusive control function is realized by a device other than a storage device. Specifically, the relay device connected to the plurality of computers and the storage device via the communication path is caused to execute the exclusive control. For this reason, the relay device has information indicating whether the storage area on the storage device is an exclusive access area, and based on this information, the relay device requests access to the storage area received from the computer. Is a request to access the exclusive access area. Then, in the case of an access request to the exclusive access area, an access refusal response is transmitted to the computer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this. FIG. 1 shows an example of a computer system according to the present invention. The computer system includes a plurality of computers 100.
0, one or a plurality of storage devices 1800, a plurality of computers 10
00 and one or a plurality of storage devices 1800, a relay device 1100 connected to each of them via a communication path 1110 and a communication path 1130, and a terminal device 1900 for remote operation connected to the relay device 1100 via a communication path. Have.

The relay device 1100 is a port 1110 for connecting to a computer and a port 1 for connecting to a storage device.
130, I / O processing device 12 connected to port 1110
00, I / O processor 14 connected to port 1130
00, a control device 1600 for controlling the relay device 1100,
Switching device 1700 for switching paths between I / O processing devices
Have.

The I / O processing devices 1200 and 1400 are
A port buffer 1210 connected to the port 1110 or the port 1130 for temporarily storing data received from the port or data transmitted from the port, the I / O processing device 1
An I / O processor 1220 that controls the 200, an exclusive control unit 1230 that determines whether the request received by the I / O processing device is a request related to exclusive control, and a virtual information table 1247 and an exclusive information table 1245 described below are stored. A memory I / O information storage unit 1240, a data temporary storage memory 1270 for temporarily storing data received by the I / O processing device, a communication I / F unit 1250 for communicating with the control device 1600, and a path. Switching device 17
00, and a distribution unit that divides the access request received from the computer into an access request to a storage area that requires virtualization processing and an access request to a storage area that does not require virtualization processing. 1280, which are connected to each other by a communication path such as an internal bus (not shown). Although the distribution unit 1280 and the exclusion determination unit 1230 are implemented by hardware in this embodiment, the I / O processor 1220 executes the program stored in the I / O information storage unit 1240. Sorting section 128
0 and the determination unit 1230 may be realized.

The control device 1600 is a memory for storing detailed exclusive information 1612, an access history table 1614, and a virtual configuration information table 1616, which will be described later, and a control processor 1620 for controlling the control device 1600. I / O processing devices 1200 and 14
00 and a communication I / F unit 1630 for connecting to
These are connected to each other via an internal communication path such as an internal bus (not shown).

The path switching device 1700 is composed of switches and the like.

The computer 1000 has a processor (not shown), a main memory (not shown), and a cache memory 1005 for temporarily storing data transmitted and received via the communication path 1115. Are connected to each other via an internal communication path such as an internal bus (not shown).

1. Virtualization Setting Method in Relay Device First, referring to FIGS. 1 and 11, the relay device 1100
The setting method of virtualization in the above will be described. The virtualization setting in the relay device means the setting of the configuration of the virtual volume performed in advance for performing the virtualization process. The virtualization process means a process for providing a computer with a specified number of virtual volumes having a specified capacity and function.

The virtualization setting consists of two processing steps. The administrator of the storage device sends the terminal device 190 to the relay device.
It is a step of registering the setting content via 0 and a step of validating the setting content.

In the step of registering the setting contents, first, in accordance with an instruction input from the administrator to the terminal device 1900, the capacity of the virtual volume, the virtual volume and the actual storage area in the storage device (hereinafter called real volume) 11 and the function of the virtual volume are registered in the all virtual configuration information table 1616 shown in FIG. Next, a virtual input / output port (hereinafter referred to as a virtual port) is assigned to the virtual volume according to an instruction input to the terminal device 1900, and the identification information of the assigned input / output port is stored in the all virtual configuration information table 1616. Be registered with. Here, the all virtual configuration information table 1616 is composed of three information parts. The virtual port unit 231 shown in FIG.
0, virtual LUN unit 2320, and real storage device information unit 23
Thirty. The virtual port unit holds the port address of the virtual port and the address to the virtual LUN unit. Virtual L
The UN unit holds the capacity of the virtual LUN, header information such as function information and virtual table information, and an address to the real storage device information unit 2330 for each specific logical block address (LBA). The virtual LUN is included in the virtual table information.
The I / O processing device having the copy locally is held as bitmap information. The real storage device information section holds an access destination descriptor (constituted by a real port address and a LUN number) of the real storage device, a function, and characteristic information.

Next, the relay device investigates the function and characteristics of the storage device in which the real volume forming the virtual volume exists, and registers the investigation result in the all virtual configuration information table 1616 as the attribute of the storage device. The functions and characteristics of the storage device may be registered in the all virtual configuration information table 1616 based on the information input to the terminal device by the administrator. Here, the function of the storage device includes, for example, the presence or absence of the exclusive control function of the storage device, and the characteristic of the storage device includes the capacity of the real volume in the storage device. Next, the relay device allocates a virtual address to the virtual port to enable the computer to access the virtual port, and also enables the computer to access the virtual volume allocated to the virtual port. A virtual logical unit number (hereinafter referred to as a virtual LUN) is assigned to the virtual volume, and the virtual address and virtual LUN of the virtual port are registered in the all virtual configuration information table 1616.

The administrator of the computer system uses the terminal device 19
When it is instructed to validate the registered contents for each arbitrary virtual port registered in the all virtual configuration information table 1616 via 00, the computer can confirm the existence of the virtual volume.

2. Operation of Relay Device Next, with reference to FIG. 1, an outline of a process executed by the relay device 1100 when the relay device receives an access request to the storage area in the storage device from the computer 1000 will be described.

The computer 1000 issues an access request frame to the relay device 1100 in order to access the shared data stored in the storage device 1800. Relay device 110
0 receives the access request frame transmitted from the computer via the port 1110, and stores the access request frame in the port buffer 1210 in the I / O processing device 1200.

The distribution unit 1280 is the port buffer 12
It is detected that the access request frame is stored in 10, and the header in the access request frame is extracted. The header includes an access request frame issuing source ID, an access destination ID (virtual port address), information indicating a frame type, a sequential number, and the like. Here, as the type of frame, there are a frame having an operation description block of the storage device, a response frame from the storage device, a write permission response frame from the storage device, and the like. The distribution unit 1280 analyzes the frame by examining the information indicating the frame type of the extracted header. As a result of the analysis, when it is detected that the access request frame has the operation description block, the distribution unit 1280 extracts the operation description block and the virtual LUN. Here, the operation description block is a command for operating the storage device, and refers to a read command for reading data from the storage device, a write command for writing data to the storage device, and the configuration of the storage device. There is a state configuration reference system command for executing exclusive control and an exclusive control system command for requesting exclusive control. The exclusive control system commands include an exclusive access area setting request and an exclusive access area release request. The distribution unit 1280 takes out the operation description block and the virtual LUN, and then creates an internal message including the header information, the operation description block, the virtual LUN, and the information inside the relay device.

Next, the distribution unit 1280 investigates the necessity of virtualization processing. The necessity of virtualization processing is the access destination ID and virtual L included in the header of the access request frame.
It is determined by the distribution unit comparing UN (hereinafter, a combination of the access destination ID and the virtual LUN is referred to as an access destination descriptor) with the access destination descriptor registered in the virtual configuration information table 1247. Here, the virtual configuration information table 1247 is stored in the I / O information storage unit 1240 of the I / O processing device. The virtual configuration information table 1247 stores a subset of the configuration information preset according to the information input by the administrator of the computer system via the terminal device 1900. It is stored in the all virtual configuration information table 1616 in the control device shown.

When the access destination descriptor matches the virtual port address and virtual LUN registered in the virtual configuration information table, the distribution unit 1280 is associated with this virtual port address and virtual LUN from the virtualization configuration information table. The access destination descriptor (hereinafter referred to as the real access destination descriptor) of the real volume of the existing storage device is acquired, and this real access destination descriptor is inserted into the above-mentioned internal message. Then, the distribution unit 1280 transmits this internal message to the I / O processor 1220 and the exclusion determination unit 1230.

On the other hand, the virtual port address and virtual LU whose access destination descriptor is registered in the virtual configuration information table
If it does not match N, the distribution unit 1280 specifies in the internal message that the access destination descriptor does not match, inserts the access destination descriptor in the internal message, and
Send this internal message to the I / O processor.

The I / O processor which has received the internal message specifying that the access destination descriptors do not match is
An inquiry request as to whether the access destination descriptor matches the virtual port address and virtual LUN registered in the all virtual configuration information table 1616 is transmitted to the control device 1600 as an internal message. In the control device, control processor 1
620 searches the all virtual configuration information table 1616, and checks whether the virtual port address and virtual LUN that match the access destination descriptor stored in the received internal message are registered.

When the virtual port address and the virtual LUN that match the access destination descriptor are registered in the all virtual configuration information table, the virtual processor information in the all virtual configuration information table 1616 related to this access descriptor is stored in the control processor 1620. Read out and send it to the I / O processing device that made the inquiry. Further, the control processor adds the ID of the I / O processing device as the inquiry source to the virtual configuration information in the all virtual configuration information table 1616 relating to the virtual port address and the virtual LUN as related information. The I / O processing device that receives the virtual configuration information from the control processor 1620
The received virtual configuration information is registered in the virtual configuration information table 1247 under the control of the I / O processor 1220.
After that, the distribution unit 1280 determines that the access destination descriptor included in the above access request is the virtual configuration information table 12
Virtual port address and virtual LUN registered in 47
The same process as the process in the case of matching with is executed.

On the other hand, the virtual port address and virtual LU that match the access destination descriptor in all virtual configuration information tables
If N is not registered, the control processor 1620 notifies the inquiry source I / O processing device that this access destination descriptor is not registered. In the I / O processing device that has received this notification, the distribution unit 1280 transmits this internal message to the route selection unit 1260 without changing the internal message having the operation description block described above.

After transmitting the internal message, the distribution unit 12
Reference numeral 80 stores the access request frame received from the computer in the data temporary storage memory 1270.

The I / O processor 1220 which has received the internal message starts the virtualization process. I / O processor 1
The reference numeral 220 manages the correspondence between the virtual volume provided to the computer 1000 and the actual storage device 1800 using the virtual configuration information table 1247. I / O processor 12
20 converts the access destination descriptor in the access request frame received from the computer into the actual access destination descriptor stored in the received internal message. Further, when the virtual volume indicated by the access destination descriptor in the access request frame received from the computer is composed of two or more real volumes in the storage device, these two or more are requested based on the access request frame. Create an access request frame for the storage device. I / O processor 12
20 also reflects the results of these processes in the internal message received from the distribution unit 1280. That is, when the access destination descriptor is converted, the converted access destination descriptor is written in the internal message, and when the access request frame is created, the internal messages are created by the number of created access request frames. After reflecting the processing result on the internal message, the I / O processor 1220 does not continue the virtualization processing until it receives a specific signal from the exclusion determination unit 1230. Upon receiving the signal, the I / O processor 1220 determines whether the computer 1 is to receive the signal according to the type of the received signal.
000, a response based on the operation description block stored in the internal message is returned to the computer 1000.
Or the process of sending an internal message to the storage device. When transmitting an internal message to the storage device, the I / O processor 1220 transmits the internal message to the route selection unit 1260.

The exclusion determination unit 1230 is assigned to the distribution unit 1280.
Based on the internal message received from, the exclusive determination described later is performed. As a result of the determination, when the access request received from the computer does not require exclusive control, the exclusion determining unit 1230 outputs a signal indicating that exclusive control is not required to the I / O processor 1220.
Send to. When the access request requires exclusive control, a more detailed exclusive decision is made. Therefore, the exclusive decision unit adds information indicating that exclusive control is required to the internal message received from the distribution unit 1280, and adds this information to the communication I / F. To the control device 1600 via the unit. The control device 1600 makes a detailed exclusion decision in consideration of a deadlock, which will be described later, and associates the real access destination descriptor stored in the internal message with the I / O processing device registered in the all virtual configuration information table 1612. The determination result is transmitted to the device.

In the route selection unit 1260, the received internal message and the access request frame stored in the temporary data storage memory 1270 are transferred to the route switching device 1700.
Via the internal message to the I / O processor 1400 of the storage device based on the description of the real access destination descriptor of the internal message. I / that received internal message and access request
The O processing device removes the internal message, changes the access request frame issuer ID stored in the access request frame to the ID of the relay device, and transmits the access request frame from the port to the storage device.

3. Outline of Exclusive Access Control Next, an outline of exclusive access control will be described with reference to FIGS. 6, 7, and 8.

FIG. 8 shows an exclusive access area setting request 50.
FIG. 5 is a diagram showing how 0, a storage area access request 510 issued for reading and writing data, and an exclusive access area release request 520 are processed in time series. When an exclusive access area setting request 500 is issued from a computer, the storage area indicated by the exclusive access area setting request 500 is set as the exclusive access area 530, and that effect is also registered in the relay device. Therefore, when another computer issues an access request 510 to the storage area including the exclusive access area 530, the access request 510
Are suppressed by the relay device 1100. An event in which another computer issues an access request to the storage area set as the exclusive access area in response to a request from a certain computer is called an exclusive hit. The once-inhibited access request 510 is reissued from the computer. If the exclusive access area release request 520 has been issued by the computer that has already issued the exclusive access area setting request 500 when the access request 510 is reissued, and the exclusive control of the exclusive access area 530 has been released, the access request 510 is processed without being suppressed. By such exclusive access control, the computer issuing the exclusive access area setting request 500 can exclusively access the exclusive access area until the exclusive access area release request 520 is issued. In the above example, the access request 510 and the exclusive access area setting request 500 have the same start address and access width.

FIG. 7 shows an exclusive access area setting request 410.
An example in which the access request 420 has a larger access width is shown. When the first computer issues the exclusive access area setting request 410, the storage area indicated by the exclusive access area setting request 410 is set as the exclusive access area 411, and that effect is also registered in the relay device. Next, when the second computer issues an access request 420 to the storage area including the exclusive access area 411, this access request 420 becomes an exclusive hit to the exclusive access area 441 and is therefore suppressed by the relay device. Next, the third computer issues an exclusive access area setting request 440 to another storage area 441 that does not include the exclusive access area 411.
To issue. Then, the storage area 411 is set as the exclusive access area 441 for the third computer,
The fact is registered in the relay device. After that, when the second computer reissues the access request 420, even if the first computer has already issued the exclusive access area release request 430 for the exclusive access area 411, the reissued access request 420 will now be issued. Is an exclusive hit to the exclusive access area 441 of the third computer, and is again suppressed by the relay device. In this way, when the access width specified by the access request is larger than the width of the exclusive access area, the access request may be repeatedly generated. This phenomenon is called deadlock.

In order to avoid the occurrence of deadlock, the present invention executes the exclusive access control shown in FIG. After the first computer issues the exclusive access area setting request 300, the second computer issues the exclusive access area setting request 300.
Access request 3 for a storage area including the exclusive access area set by
When 10 is issued, the access request 310 is an exclusive hit to the exclusive access area of the first computer.
It is suppressed by the relay device. In this case, the relay device 110
0 indicates the exclusive access area at the time of exclusive hit,
The access width of the access request 310 received from the second computer is expanded. When the exclusive access area setting request 340 for the storage area included in the expanded exclusive access area is issued from the third computer due to the expansion of the exclusive access area, the exclusive access area setting request 340 is expanded. Since the request is an exclusive access area setting request to the exclusive access area, it is suppressed by the relay device. The first computer requests exclusive access area release 3
When 20 is issued, the exclusive control for the expanded exclusive access area is released. Therefore, if the second computer subsequently reissues the access request 310, this access request is processed without being suppressed by the relay device.
The access request 310 is reissued after the relay device cancels the exclusive control for the expanded exclusive access area.
It may be executed by the relay device itself.

4. Exclusive access control processing operation FIG. 2 shows an exclusive information table 12 stored in the I / O processing device.
It is a figure which shows an example of 45. The exclusive information table exists for each virtual volume shown to the computer connected to the I / O processing device, and the entry contains the address 20 for each computer.
00, area length 2010, and I / O attribute 2020 are stored. The address is the start address of the exclusive access area, the area length means the number of logical blocks in the exclusive access area, and the I / O attribute is the type of exclusive control (read sharing, exclusive write, exclusive read, This means the read / write exclusive) and exclusive control identification number (reservation ID).

FIG. 3 is a diagram showing an example of the detailed exclusive information table 1612 stored in the control device 1600. The detailed exclusive information table 1612 exists for each virtual volume shown to the computer connected to each I / O processing device in the relay device, and the entry has the same information as the information managed by the exclusive information table for each computer (address 2110, In addition to the area length 2120 and I / O attribute 2150), the start address of the expanded exclusive access area (expansion address 21) when the exclusive access area is expanded and exclusive control is executed
30) and the number of logical blocks in the expanded exclusive access area (expansion area length 2140) are stored.

Next, with reference to FIG. 4, a processing procedure of exclusive control executed in the relay device 1100 in consideration of avoiding occurrence of deadlock will be described. The exclusive control processing is performed when the relay apparatus 1100 performs all the exclusive control processing (hereinafter, referred to as all processing cases), and the storage apparatus that does not have the exclusive control function is provided with the exclusive control function by the relay apparatus. When the device has the exclusive control function, a part of the processing procedure is different when the storage device executes the exclusive control (hereinafter, referred to as a selection processing case). Therefore, the processing procedure will be described below for each case.

4-1. All processing cases First, all processing cases will be described. Exclusive control is
It is composed of two types of processing or control: (1) setting and cancellation of the exclusive access area, and (2) expansion and suppression determination control of the exclusive access area when receiving an access request.

(1) Setting and Release of Exclusive Access Area When the exclusion judgment unit 1230 in the I / O processing device 1200 receives an internal message from the distribution unit 1280, it refers to the operation description block included in the internal message and the The type of received access request frame is determined.

When the type of the access request frame is the exclusive access area cancellation request (YES in step 105), the exclusive control cancellation processing is performed for the exclusive access area indicated by the access request frame (step 15).
5). In this case, the exclusive access area release request is sent from the I / O processing device 1200 to the control device 1600 by an internal message. In the control device 1600, the control processor 1620 uses the detailed exclusion information table 1612 stored in the control information storage unit 1610 to determine the issuer ID included in the exclusive access area cancellation request frame for the requesting computer in the detailed exclusion information table. When a table that matches the registered request source ID) is searched and the identification number stored in the attribute portion 2150 of the table obtained by the search matches the identification number of the exclusive access area cancellation request frame, , The entry (ie the address part,
Area length, attribute, expanded address, expanded area length) are reset to 0. After the detailed exclusive information table 1612 is updated, or when the table for the requesting computer cannot be extracted from the detailed exclusive information table 1612, the identification number described in the attribute section and the identification number of the exclusive access area release frame are If they do not match, the control device 1600 extracts the I / O processing device associated with the access destination descriptor included in the exclusive access area cancellation request frame from the all virtual configuration information table 1616,
A request for changing the exclusive information table 1245 is sent to the I / O processing device by an internal message. In the I / O processing device that has received the internal message, the I / O processor 1220 outputs the issuer ID included in the exclusive access area cancellation request frame from the exclusive information table 1245 to the exclusive information table 1
A table matching the request source ID registered in 245 is searched, and if the identification number registered in the attribute section 2020 of the corresponding table matches the identification number included in the exclusive access area cancellation request frame, the entry concerned. (Namely, address part, area length, attribute) is set to 0. The I / O that received the exclusive access area release request frame
The I / O processor of the processing device creates a response message indicating the completion of the exclusive access area release processing and sends it to the transmission source computer of the exclusive access area release request frame. Through the above processing, the exclusive access area releasing processing is completed.

If the access request frame is a frame that is not subject to exclusive access control requesting processing that does not involve reading and writing to the storage device, such as acquisition of configuration information and sense information (NO in step 110), the exclusion determining unit 1230 determines exclusive access. The processing relating to the control is ended, and a signal indicating that exclusive control is not required is transmitted to the I / O processor 1220.

When the access request frame is the frame subject to exclusive control and the access request frame requesting the setting of the exclusive access area (exclusive access area setting request frame) (step 120YES), the exclusion judging unit 1230 controls The determination request is transmitted to the device 1600 by an internal message.

In the control device 1600, the control processor 1620 causes the exclusive access area setting request frame relating to the determination request received from the exclusion determination unit 1230 to have the exclusive access area already set (including the expanded exclusive access area). ) Is determined based on the detailed exclusive information table 1612. When the exclusive access area setting request frame does not accompany the address or expanded address registered in the detailed exclusive information table 1612 and the exclusive access area setting request to the storage area indicated by the area length or the expanded area length (NO in step 145) The control processor registers the information included in the exclusive access area setting request frame in the detailed exclusive information table 1612. Also, the exclusive access area setting request frame is the detailed exclusive information table 1612.
2110 and area length 212 registered in
0, or expanded address 2130 and expanded area length 21
Even if the request for setting the exclusive access area to the storage area indicated by 40 is made, the attribute of the exclusive access area requesting the setting and the attribute portion 2150 of the detailed exclusive information table
Attributes registered in (read sharing, exclusive writing,
Exclusive read, read / write exclusive) and control processor 16
As a result of the comparison made by 20, when the control processor determines that exclusive access can be granted to the computer that issued the exclusive access area setting request frame (step 145N
O), information included in the exclusive access area setting request frame is registered in the detailed exclusive information table 1612 (step 150).

Here, if the attribute information of the exclusive access area setting request frame and the attribute registered in the attribute section 2150 of the detailed exclusive information table are in any combination, the exclusive access area setting request frame is transmitted. Figure 5 shows whether exclusive access is allowed to the original computer.
Shown in. For example, if the attribute information included in the exclusive access area setting request frame is exclusive reading, and if the attribute information registered in the attribute portion 2150 of the detailed exclusive information table 1612 is exclusive writing, the issuer of the exclusive access area setting request frame Exclusive access to the computer is permitted, but the attribute part 2 of the detailed information table 1612
If the attribute information registered in 150 is exclusive read, exclusive access cannot be granted to the issuing source computer of the exclusive access area setting request frame.

The control processor is the detailed exclusive information table 1
The information registered in 612 includes the start address of the exclusive access area in the exclusive access area setting request frame, the area length,
It is an I / O attribute. After updating the table, the control processor searches the all virtual configuration information table 1616 for the I / O processing device associated with the access destination descriptor indicated by the exclusive access area setting request frame, and the exclusive information table is assigned to this I / O processing device. Submit a change request for. I / O in I / O processor
The processor registers the same value (start address, area length, I / O attribute) as the value registered in the detailed exclusion information table in the corresponding entry of the exclusion information table 1245 stored in the I / O information storage unit. To do. Then, the I / O processor of the I / O processing device that received the exclusive access area setting request frame creates a response message indicating the completion of the exclusive access area setting processing, and responds to the transmission source computer of the exclusive access area setting request frame. Send the message and finish the process.

(2) Expansion and exclusion of exclusive access area When the access request frame received from the control computer is the frame subject to exclusive control (step 110 YES) and is not the exclusive access area setting request frame (step 120 NO), exclusive access Based on the information table 1245, the exclusion determination unit 1230 determines whether the access request frame is an access request frame with an access request to the storage area including the exclusive access area (exclusive access area before expansion) set when the exclusive access area setting request frame is received. In addition, when an access request is made to the storage area including the exclusive access area before expansion, it is determined whether the exclusive access area is an exclusive access area to which access permission is possible based on the table shown in FIG. (Step 125).

As a result of the determination, if the access request frame does not include the access request to the exclusive access area before expansion, or if the access request frame includes the access request to the exclusive access area before expansion, the exclusive access When the area is an exclusive access area that can be accessed based on the table of FIG. 5 (step 125 NO)
, The exclusion determining unit 1230 transmits a signal indicating that exclusion control is not required to the I / O processor 1220, and ends the process.

As a result of the determination, the access request frame includes an access request to the exclusive access area before expansion,
If it is determined that the exclusive access area is an inaccessible exclusive access area based on the table of FIG. 5, whether the access area indicated by the access request frame received from the computer crosses the exclusive access area. (Whether to include exclusive access area and other storage area)
The exclusion determination unit 1230 transmits an internal message requesting that the determination be made to the control device 1600. Then, the control processor 1620 of the control device 1600 determines based on the detailed exclusion information table 1612 whether the access area indicated by the access request frame received from the computer crosses the exclusive access area already set at the time of the determination ( Step 130). In step 145, if the exclusive access area setting request frame received from the computer includes the exclusive access area setting request for the already set exclusive access area, and the exclusive access cannot be permitted based on FIG. Even when it is determined that the frame is the exclusive access setting request frame including the exclusive access area setting request for the determined exclusive access area, the process shown in step 130 is executed.

When crossing the exclusive access area (step 1
30)), the control processor 1600 calculates the start address and exclusive area length of the exclusive access area so as to include the access area indicated by the access request frame received from the computer. Then, the control processor 1600 reflects the calculation result in the detailed exclusive information table 1612.
Extended address part 213 of the corresponding entry in the table
0 and the enlarged area length 2140 are updated (step 13).
5).

After updating the detailed exclusive information table, or when it is determined in step 130 that the exclusive access area is not crossed (NO in step 130), the control processor 1
Reference numeral 600 returns the internal message to the I / O processing device that issued the internal message, and the I / O processing device that receives this message performs the process of suppressing the access request received from the computer.
The suppression processing is executed by the I / O processor 1220 in the I / O processing device that creates a response that clearly indicates that the access request has been suppressed due to an exclusive hit, and returns the response to the transmission source computer of the access request frame. (Step 14
0).

4-2. Selection Processing Case Next, the selection processing case will be described with reference to FIG. (1) Setting and Release of Exclusive Access Area When the exclusion judgment unit 1230 in the I / O processing device 1200 receives an internal message from the distribution unit 1280, the access received from the computer by referring to the operation description block included in the internal message Determine the type of request frame.

When the access request frame is the exclusive access area cancellation request frame (YES at step 105), the exclusion control for the corresponding exclusive access area is canceled (step 155). In this case, the exclusive access area release request is issued from the I / O processing device 1200 to the control device 16
00 by internal message. Control device 16
In 00, the control processor 1620 causes the control information storage unit 1
Detailed exclusion information table 1612 stored in 610
From the request source computer (the source ID included in the exclusive access area cancellation request frame matches the request source ID registered in the detailed exclusive information table), and the table obtained by the search is searched. If the identification number stored in the attribute section 2150 matches the identification number of the exclusive access area cancellation request frame, the entry (that is, address section, area length, attribute, expanded address,
Reset extended address length) to 0. Further, the control processor 1620 resets all the entries in the detailed exclusive information table in which the ID of the requesting computer is not registered to 0. After the detailed exclusion information table 1612 is updated, or when the table for the requesting computer cannot be extracted from the detailed exclusion information table 1612, the identification number stored in the attribute section and the identification number of the exclusive access area release frame are If they do not match, the control device 1600 extracts the I / O processing device associated with the access destination descriptor included in the exclusive access area cancellation request frame from the all virtual configuration information table 1616,
A request for changing the exclusive information table 1245 is sent to the I / O processing device by an internal message. In the I / O processing device that has received the internal message, the I / O processor 1220 uses the exclusive information table 1245 to determine the issuer ID included in the exclusive access area cancellation request frame as the request source ID registered in the exclusive information table 1245. When a matching table is searched and the identification number registered in the attribute section 2020 of the corresponding table matches the identification number of the exclusive access area cancellation request frame, the entry (that is, address section, area length, attribute) To 0.

After transmitting the internal message to the I / O processor, the control processor sets the real access destination descriptor registered in association with the access destination descriptor indicated by the exclusive access area release request frame in the entire virtual configuration information table. 161
6, and sends an internal message to the I / O processing device connected to the storage device so that the access area release request is sent to the real storage device indicated by the real access destination descriptor. The I / O processing device that receives this internal message sends an exclusive access area release request to the storage device. At the time when the responses are received from all the destination storage devices of the exclusive access area release request transmitted from the I / O processing device,
The control processor transmits an internal message to the I / O processor 1220 connected to the transmission source computer of the exclusive access area release request frame. The I / O processor that received this internal message creates a response message indicating the completion of exclusive access area release processing, and sends this to the source computer of the exclusive access area release request frame,
The processing of the exclusive access area release request ends.

When the access request frame is a frame which is not subject to exclusive access control in which reading / writing from / to the storage device such as acquisition of configuration information or sense information does not occur (step 110 NO), the exclusion determination unit 1230 executes processing relating to exclusive access control. Upon completion, a signal indicating that exclusive control is not required is transmitted to the I / O processor 1220.

When the access request frame is a frame subject to exclusive control and is an exclusive access area setting request (step 120 YES), the exclusion determination unit 1230 sends a determination request to the control device 1600 by an internal message.

In the control device 1600, the control processor 1620 receives the exclusive access area setting request frame relating to the determination request received from the exclusion determination unit 1230, and sets the exclusive access area that has already been set (including the expanded exclusive access area). ) Is determined based on the detailed exclusive information table 1612. It is determined that the exclusive access area setting request frame accompanies an access request to the already set exclusive access area (including the expanded exclusive access area) and that exclusive access cannot be permitted based on FIG. When the frame is the exclusive access area setting request frame including the exclusive access area setting request for the exclusive access area (YES in step 145), the process shown in step 130 is executed. If the exclusive access area setting request frame does not accompany an exclusive access area setting request to the storage area indicated by the address and area length or expanded address and expanded area length registered in the detailed exclusive information table 1612, or exclusive access area setting Address 2 where the request frame is registered in the detailed exclusive information table 1612
110 and the area length or the expanded address 2130 and the request for setting the exclusive access area to the storage area indicated by the expanded area length, the attribute of the exclusive access area requesting the setting and the detailed exclusive information table Attribute part 21
As a result of the control processor 1620 comparing the attribute registered in 50 with the control processor 1620 based on FIG. 5, if the control processor determines that the computer that issued the exclusive access area setting request frame can be granted exclusive access, The control processor executes the following processing.

In the control processor, the real access destination descriptor associated with the access destination descriptor included in the exclusive access area setting request frame and the storage device in which the real volume indicated by the real access descriptor exists are exclusive control functions. The attribute information of the storage device, which indicates whether or not it has, is acquired from the all virtual configuration information table 1630. The control processor refers to the acquired attribute information and, if there is a storage device having the exclusive control function, sends an internal message to the I / O processing device connected to the storage device having the exclusive control function. Then, the exclusive access area setting request frame is duplicated and an instruction is sent to the storage device. In the I / O processing device that has received the internal message, the I / O processor creates a copy of the exclusive access area setting request frame, sends it to the storage device, and waits for a response from the storage device. When the I / O processor receives the response, the response is sent to the controller and the control processor 1620 analyzes the content of the response.

If there is a response indicating that the exclusive access area has already been set by a request from another computer (hereinafter referred to as a device hit), it corresponds to a case where the determination result of step 145 is YES. . In this case, the control processor sends an internal message to the I / O processing device connected to the destination storage device of the exclusive access area setting request frame, and has the same identification number as the exclusive control of the exclusive access area setting request frame. The exclusive access area release request having the identification number of is generated and is instructed to be transmitted to the storage device. I / received internal message
In the O processor, an exclusive access area release request is created based on the internal message, this is sent to the storage device,
Wait for a response from the storage device. After the I / O processing device receives the response from all the destination storage devices of the exclusive access area release request, the processing shown in step 130 is executed.

When all the responses received from the storage device indicate that the setting of the exclusive access area has been completed (not a device hit), or as a result of the control processor referring to the attribute information acquired from the all virtual configuration information table 1616,
When it is determined that the storage device having the exclusive control function does not exist, the control processor registers the information included in the exclusive access area setting request frame received from the computer in the detailed exclusive information table 1612. The registered information is the start address of the exclusive area, the area length, and the I / O attribute. After updating the detailed table, the control processor searches the all virtual configuration information table for the I / O processing device associated with the access destination descriptor included in the exclusive access area setting request frame, and the exclusive information table is assigned to this I / O processing device. Submit a change request. In the I / O processing device that has received the change request, the I / O processor has the same value as the value registered in the detailed exclusive information table in the corresponding entry of the exclusive information table 1245 described in the I / O information storage unit. Register (start address, area length, I / O attribute). Then, the I / O processor creates a response message indicating the completion of the exclusive access area setting processing, transmits this response message to the transmission source computer of the exclusive access area setting request frame, and ends the processing. (2) If the access request frame received from the access area expansion / inhibition control computer for access request is the frame subject to exclusive control (step 110 YES) and is not the exclusive access area setting request frame (step 120 NO), the received access is received. Whether the request frame is an access request frame with an access request to the storage area including the exclusive access area before the expansion of the exclusive access area setting, and an access request to the storage area including the exclusive access area before the expansion In this case, it is determined whether the exclusive access area is an exclusive access area that can be accessed based on the table shown in FIG.
The exclusion determination unit 1230 makes a determination based on 245 (step 125).

As a result of the determination, if the access request frame does not include an access request to the exclusive access area before expansion, or if the access request frame includes an access request to the exclusive access area before expansion, the exclusion When the access area is an exclusive access area accessible based on the table of FIG. 5 (step 125 NO)
, The exclusion determining unit 1230 transmits a signal indicating that exclusion control is not required to the I / O processor 1220, and ends the process.

As a result of the determination, the access request frame includes an access request to the exclusive access area before expansion,
When the exclusive access area is an inaccessible exclusive access area based on the table of FIG. 5, the exclusion determination unit 1230 sends an internal message to the control device 1600 and the access area indicated by the access request frame received from the computer. Command to determine whether or not to cross the exclusive access area. Upon receiving the internal message, the control processor 1620 of the control device receives the detailed exclusive information table 1
Based on 612, it is determined whether the access area indicated by the access request frame straddles the exclusive access area (step 130).

When straddling the exclusive access area (step 1
30YES), the control processor 1600 calculates the start address and exclusive area length of the exclusive access area so as to include the access area indicated by the access request frame received from the computer. Then, the control processor 1600 reflects the calculation result in the detailed exclusive information table 1612, so that the expanded address part 2 of the corresponding entry in the table is reflected.
130 and the enlarged region length 2140 are updated (step 1
35).

It should be noted that, in step 135, even if the exclusive access area is not crossed, if it is determined in step 145 that a device hit has occurred, a special area expansion process is executed. That is, the control processor creates a detailed exclusive information entry in which the request source computer does not exist (the request source ID does not exist), and each of the start address and the area length included in the exclusive access area setting request frame received from the computer for the entry. Is registered in the enlarged address part 2130 and the enlarged area length 2140. Also, the control processor is the I / O of the detailed exclusive information table.
In the attribute 2150, read / write exclusion is registered as the exclusion type, and 0 is registered as the exclusion control identification number.

After updating the detailed exclusive information table, or when it is determined in step 130 that the exclusive access area is not crossed and updating of the detailed exclusive information table is not required (step 130 NO), the control processor 1600 transmits the access request frame. Sends an internal message to the I / O processor connected to the original computer, and instructs it to perform access request suppression processing. The I / O processor 1220 of the I / O processing device that has received the internal message creates a response that clearly indicates the content of the suppressed access request, and sends it to the transmission source computer of the access request frame.

As described above, the relay apparatus 1100 capable of the virtualization processing sets only the access request which is the virtualization processing target as the exclusive control target, and the I / O processing apparatus in the relay apparatus performs the exclusive control. Detect only required access requests,
The control device 1600 makes a detailed exclusive control determination only for the access request selected by the I / O processing device. As a result, the load of exclusive control determination can be dispersed, and exclusive control can be efficiently realized.

Further, of the access requests issued by the computer 1000, for the requests that require access inhibition as a result of the exclusive control determination, the access inhibition processing is executed between the computer 1000 and the relay device 1100. Therefore, the access denial response generated by the exclusive control and the reissued access request are transmitted and received between the relay device and the computer that is the reissue source of the access request, and therefore the communication line 1135 between the relay device and the storage device. Does not affect the performance of. Therefore, when a computer that has the exclusive access right accesses the exclusive access area, or when another computer accesses a storage area other than the exclusive access area, the access denied response or the denied access computer It is not affected by reissued access requests.

Further, even when the storage device does not have the exclusive control function, the relay device allocates to this storage device a virtual volume having the same storage capacity as the storage device, and the exclusive control function is applied to the virtual volume. The exclusive control can be executed by providing When a storage device having an exclusive control function and a storage device not having the exclusive control function coexist in a plurality of storage devices connected to the network, the exclusive control is performed on the storage device having the exclusive control function. The relay device instructs the storage device not to have the exclusive control function, and the relay device executes the exclusive control function for the virtual volume as described above to provide the exclusive control function to the storage device that does not have the exclusive control function. You can Further, the relay device can provide the exclusive control function to all the storage devices regardless of whether or not the storage device has the exclusive control function.

When the relay device has a virtualization function,
1) The relay device uniformly provides the exclusive control function to all virtual volumes, or 2) the storage device that does not have the exclusive control function among the storage devices associated with the virtual volume is previously used as the relay device. The relay device provides the exclusive control function to the virtual volume of the storage device that does not have the exclusive control function, so that the computers have volumes having the exclusive control function uniformly. It is possible to look like.

Next, another embodiment of the present invention will be described. In this embodiment, the data in the storage device and the data in the local cache memory are compared with the local cache memory (write-through format) that the computer has for the purpose of temporarily storing the data in the storage device. A method of instructing the relay device to maintain the consistency with the following will be described. Specifically, the relay device 1100
Has an access history table for storing the history of read access requests received from the computer, and the relay device identifies the data to be invalidated among the data stored in the cache on the computer based on the access history table. , The invalidation request message is transmitted to the computer having this cache upon a predetermined event.

The system configuration is almost the same as the system configuration shown in FIG. 1, but the control information storage unit 1610 of the relay device 1100 has an access history table 1614 for storing the history of access requests. FIG. 9 shows an example of the access history table. The access history table is provided for each volume provided to the computer. The access history table has an entry 2200 for each computer, for each logical block address, or for each group of a certain number of blocks. The numerical value taken by the entry is a binary value of 0 or 1, and when it is 1, it indicates that the computer corresponding to the entry has previously issued a read access request to the corresponding address of the logical block corresponding to the entry.

The control processor of the relay device is the distribution unit 1
Using the internal message generated at 280, it is determined whether the access request frame received from the computer is related to the read access request, and the access history table is updated. Specifically, when the relay device 1100 receives a read access request frame from the computer 1000, the distribution unit 1210 generates an internal message. This internal message is transmitted from the communication I / F unit 1250 to the control device 1600. In the control device 1600, the control processor 1620 analyzes the operation description block and the actual access destination descriptor included in the internal message, and when the access request frame received from the computer is related to the read access request, the access 1 is registered in the entry of the access history table 1614 corresponding to the destination descriptor and the access request frame transmission source computer. The internal message received by the control device may be temporarily buffered in the I / O information storage unit 1610 in the I / O processing device, and the access history table update process may be executed at a specific trigger. In this case, the control device 1600 cannot specify the content of the buffered internal message before a specific trigger comes. Therefore, when a failure occurs in the I / O processing device, it is necessary to execute the invalidation process for the entire local memory of the computer connected to the I / O processing device.

The invalidation request message is sent to the relay device 110.
It is generated when 0 receives a write access request or an exclusive access area setting request. Specifically, when the relay device receives the write access request frame or the exclusive access area setting request frame from the computer, the distribution unit 1280 generates an internal message and transmits it to the control device 1600. Control processor 1
620 analyzes the internal message, and acquires the access history from the entry of the access history table corresponding to the access area indicated by the access destination descriptor included in the internal message. Then, the control device identifies the computer and the storage area to be invalidated (corresponding to the entry in which 1 is registered) from the acquired access history, and the I / O processing for communicating with the computer to be invalidated An internal message in which information indicating a storage area to be invalidated is inserted is transmitted to the device. Control processor 16 after sending internal message
30 resets the entry for which the access history is acquired to 0.

In the I / O processing device, the invalidation request message sent by the I / O processor to the computer is created using the internal message received from the control device. The invalidation request message is transmitted as an event notification that is asynchronously transmitted to the computer. When the computer receives the invalidation request message, the network driver or the OS executes the invalidation processing of the cache 1005 based on the invalidation request message.

As described above, the relay device 1100
Then, the reception of the read access request is detected by the I / O processing device, and the control device 1600 updates the access history table 1614 based on the detection result to retain the access history. In addition, a predetermined type of access request
When the I / O processing device receives it, the control device refers to the access history table and instructs the I / O processing device to create the invalidation request message. The I / O processing device creates an invalidation message based on the instruction from the control device and sends it to the computer. As a result, the cache invalidation process is executed in the computer.

The exclusive control method having the processing for avoiding the occurrence of the deadlock described above can be executed in a memory system having a main storage device to which a plurality of processors are connected. FIG. 10 shows an example of a memory system. The memory system includes a plurality of processors (IP) 10, a main storage device 60, and an intermediate storage device 30 that connects the plurality of processors and the main storage device 60. Intermediate storage device 30
Has a cache memory device 50, an exclusive control device 45, and a suppression request management device 55. Further, the exclusion controller 45 has an exclusion information storage unit 35 and an exclusion determination unit 40. The exclusive control is mainly executed by the exclusive control device 45. In the exclusive control device 45, the information required for exclusive control is stored in the exclusive information storage unit 35, and the exclusive determination unit 40 performs the determination shown in FIG. If it is determined that the memory request needs to be suppressed, the suppression request management device 55 executes the suppression process.

In addition to the memory system shown in FIG. 10, a storage device (NAS: Network
Even in the case of Attached Storage), the exclusive control method having the processing for avoiding the above-mentioned deadlock can be executed.

[0080]

According to the present invention, deterioration of network performance due to exclusive control is prevented, and a computer can access a storage area exclusively regardless of whether or not the storage device has an exclusive control function.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a computer system.

FIG. 2 is a diagram showing an example of an exclusive information table in an I / O processing device.

FIG. 3 is a diagram showing an example of a detailed exclusive information table in the control device.

FIG. 4 is a flowchart illustrating an example of a processing procedure of exclusive access control.

FIG. 5 is a diagram showing whether or not access is possible depending on the type of exclusive access area.

FIG. 6 is a diagram showing an example of an exclusive control method.

FIG. 7 is a diagram illustrating an example of an exclusive control method that does not perform expansion processing of an exclusive access area.

FIG. 8 is a diagram showing another example of the exclusive control method.

FIG. 9 is a diagram showing an example of an access history table.

FIG. 10 is a diagram showing a configuration example of a memory system.

FIG. 11 is a diagram showing an example of an all virtual configuration information table.

[Explanation of symbols]

1000 ... Calculator 1100 ... Relay device 1200 ... I / O processor 1400 ... I / O processing device 1600 ... Control device 1700 ... Route switching device 1800 ... Storage device 1900 ... Terminal device

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G06F 15/177 682 G06F 15/177 682F 682K (72) Inventor Hiroshi Yamada 1099, Ozenji, Aso-ku, Kawasaki-shi, Kanagawa Stock company Hitachi, Ltd. System Development Laboratory (72) Inventor Hiroshi Kurokawa 1 Horiyamashita, Hadano City, Kanagawa Prefecture F-Term (Reference) 5B005 PP05 PP21 5B045 BB29 DD12 EE02 EE11 EE36 5B065 BA01 CA02 CA11 5B082 FA17 GB06 HA02

Claims (16)

[Claims] 1. A computer system comprising a plurality of computers, one or a plurality of storage devices, and a plurality of the computers and a relay device connected to the one or the plurality of storage devices, wherein the first computer is A first access request for requesting exclusive access to a first storage area in the one or more storage devices is transmitted, and the relay device transmits the first storage request based on the first access request. The area is designated as an exclusive access area, and when the relay device receives a second access request for requesting access to the first storage area from a second computer, the relay apparatus sends the area to the second computer. A computer system characterized by transmitting an access denial response. 2. The computer system according to claim 1, wherein the first computer transmits a cancellation request for canceling the designation of the exclusive access area, and the relay device is based on the cancellation request. A computer system which releases the designation of the exclusive access area. 3. The computer system according to claim 1, wherein the relay device accesses a second storage area wider than the first storage area including the first storage area from the second computer. A computer system characterized in that, when a requested second access request is received, the second storage area is designated as an exclusive access area. 4. A relay device connected to a plurality of computers and one or a plurality of storage devices, and a computer-side port for connecting to the plurality of computers, and to connect to the one or a plurality of storage devices. A storage device side port, a processor, and a memory, and a relay device excludes from the first computer to the first storage area in the one or more storage devices via the computer side port. Specific access is requested, when the first access request is received, the processor stores first information indicating that the first storage area is an exclusive access area in the memory, When the relay device receives a second access request for requesting access to the first storage area from the second computer via the computer-side port, the processor is based on the first information. Relay apparatus and controls to transmit an access denied response to the second computer. 5. The relay device according to claim 4, wherein the relay device receives a release request for requesting release of an exclusive access area from the first computer via the computer-side port, The relay device, wherein the processor controls to erase the first information from the memory. 6. The relay device according to claim 5, wherein when the first information is erased, the processor stores the information included in the second access request via the storage device side port. A relay device for transmitting to a storage device having one storage area. 7. The relay device according to claim 4, wherein the relay device, via the port on the computer side, has a second storage area that is wider than the first storage area including the first storage area from a second computer. When the second access request for requesting access to the storage area is received, the processor stores second information indicating that the second storage area is an exclusive access area in the memory. A relay device characterized by the above. 8. The relay device according to claim 7, wherein the relay device receives a third access request for requesting access to the second storage area from a third computer via the computer-side port. In this case, the processor controls to transmit an access refusal response to the third computer based on the second information. 9. The relay device according to claim 4, wherein the relay device requests reading of data from a storage area on the one or more storage devices from the first computer via the computer-side port. When the access request is received, the processor stores the third information indicating that the first computer has accessed the storage area in the memory, and the relay device, via the computer-side port, When receiving an access request requesting writing of data to the storage area from a second computer, the processor is stored in a cache memory included in the first computer based on the third information. A relay device, which sends an invalidation message for notifying that the existing data is not used to the first computer. 10. An access control, wherein a relay device connected to a plurality of computers and one or a plurality of storage devices controls access from each of the plurality of computers to a storage area in the one or a plurality of storage devices. A method, comprising: receiving from the first computer a first access request requesting exclusive access to the first storage area in the one or more storage devices; and from the second computer, And a step of receiving a second access request for requesting access to the first storage area, and a step of transmitting an access refusal response to the second computer as a response to the second access request. An access control method characterized by: 11. The access control method according to claim 10, further comprising the step of designating the first access storage area as an exclusive access area. 12. The access control method according to claim 11, further comprising the step of receiving a release request for requesting release of an exclusive access area designation from the first computer, and based on the release request, And a step of canceling the designation of the exclusive access area. 13. The access control method according to claim 12, further comprising the step of transmitting information included in the second access request to a storage device having the first storage area. Control method. 14. The access control method according to claim 11, wherein the second access request further accesses a second storage area wider than the first storage area including the first storage area. An access control method comprising the step of designating the second storage area as an exclusive access area when the access request is a request. 15. The access control method according to claim 14, further comprising: receiving a third access request for requesting access to a storage area included in the second storage area from a third computer; An access control method comprising a step of transmitting an access refusal response as a response to a third access request to a third computer. 16. A computer system having one or a plurality of storage devices and a relay device connected to the one or a plurality of storage devices and a plurality of computers, wherein the relay device is the one or the plurality of storage devices. The storage area in the device has information indicating whether or not it is an exclusive access area, and requests access to the storage area in the one or more storage devices from any of the plurality of computers. When received,
A computer system which transmits an access refusal response to the computer based on the information.