JP2006236387A - Storage control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress degradation of performance to a minimum, in executing dual writing between remotely located controllers, by restricting the number of data transfers to a minimum even if the distance between the controllers is expanded; to provide a function of leaving no intermediate result of a transaction; and to enhance the performance without requiring execution of an I/O process of control information to and from disks. <P>SOLUTION: A master controller reports back completion of receipt of write data, and then directly sends the write data to a sub controller. The secondary controller stores the received write data into a nonvolatile memory to thereby guarantee the data. Further, by setting a certain reference time point, the secondary controller can guarantee all write data up to the time point, and can discard all write data after the time point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a function of writing data twice between different control devices. The present invention is particularly effective when the distance between the control devices is long and a delay occurs in data transfer between the control devices.

  The following techniques are disclosed as known examples relating to the present invention.

  Patent Document 1 discloses a technique for performing double writing of a disk between control devices at remote locations. In the present invention, even if one control device is destroyed due to a natural disaster such as an earthquake, the data can be guaranteed with the disk of the other control device. In Patent Document 1, a primary control device that directly receives write data from a host computer transfers the received write data to a remote control device at a remote location, and then receives the write data. Report completion to the host computer. In this method, the data on the primary side and the secondary side completely coincide with each other, and this is a very good method from the viewpoint of data guarantee. However, since the data transfer time between the control devices becomes very large due to the expansion of the distance between the control devices, there is a problem in performance at a long distance.

  Patent Document 2 also discloses a technique for performing double writing of a disk between control devices at remote locations. In Patent Document 2, a primary control device that directly receives write data from a primary host computer reports the completion of reception of the write data to the primary host computer immediately after receiving the write data. . In Patent Document 2, a copy of the write data received by the primary control device is once read out by the primary host computer. In the present invention, time is given to the write data that is initially received from the primary host computer. The time means the time when the write request for writing the write data is issued. When a copy of the write data is read out to the primary host computer, the write time is also passed to the primary host computer. Thereafter, the primary host computer sends a copy of the write data and the write time to the secondary host computer.

  The secondary host computer that has received the write data and write time writes information such as the write time to the control disk. Further, referring to the time given to each write data, the write data is written to the secondary disk in the order of the write time.

  The purpose of the above-described processing by the secondary host computer in Patent Document 2 is to avoid leaving an intermediate result of a transaction normally used in an online system or the like. For example, when executing a transaction for transferring a deposit from an account A to an account B, it is possible to avoid leaving a state where no deposit is accumulated in the account B even though the deposit is deducted from the account A. Means not to leave. Normally, in an online system, the unit of recovery is a transaction, so leaving an intermediate result of a transaction is a very important obstacle.

  Next, it will be briefly described that when the above-described processing is executed, it is possible not to leave an intermediate result of the transaction. There are two types of discs in which dual writing is performed: a disc storing a database such as account information, and a disc storing a journal storing a transaction update history. When the host computer goes down, the recovery processing program analyzes the journal, and the update result of the transaction that has not been completed is returned to the state before the start of execution. Can not be. The write data written to the disk of the secondary control device is valid when the primary control device storing the latest write data has been destroyed. Although the latest write data is not stored in the control device on the secondary side, the write data up to a certain time is guaranteed. Therefore, apparently, the host computer creates a state equivalent to being down at the time when the write data is guaranteed. Therefore, by executing a process similar to the recovery process executed when the host computer goes down, using the disk storing the journal on the secondary control unit and the disk storing the database, It is possible not to leave a result in the middle of a transaction.

  Patent Document 3 discloses a technique in which a disk controller has a nonvolatile cache memory and performs write-after, that is, a write data received from a host computer is written to the nonvolatile cache memory and a completion report is made. Yes. This is because the non-volatile cache memory has high reliability, so that it can be determined that if the write data is stored here, the data can be sufficiently guaranteed.

European Patent Application 0671686 European Patent Application No. 0672985 JP-A-4-245342

  In Patent Document 2, even if the distance between the control devices is increased, some data is lost, but the degradation of performance is small. Moreover, it does not leave a result during the transaction.

  However, when the primary side host computer reads the data and transfers the data to the secondary side host computer, as in Patent Document 1, when the write data is directly transferred between the control devices. In comparison, an extra data transfer is performed once. Furthermore, it is also necessary to execute input / output processing for a storage medium such as MT.

  The object of the present invention is to transfer write data directly between control devices as in Patent Document 2, and even if the distance between the control devices is increased, the degradation of performance is suppressed to a minimum, and transaction It is to provide a function that does not leave a result on the way. Furthermore, it is not necessary to execute input / output processing of control information and the like to the disk, so that high performance is achieved.

  The following describes how the present invention achieves the objects described above.

  In the present invention, the host computer gives a write time to the write data when issuing a write request to the primary controller. When the primary controller receives the write data from the host computer, it reports completion. Thereafter, the primary control device sends write data and write time to the secondary control device. At this time, the positive control device sends the write data to the sub control device in the order of the write time. As described above, even when the distance between the control devices is increased, the performance deterioration can be suppressed to a small extent.

  The secondary control device stores the write data received from the primary control device in the non-volatile cache memory. As a result, it is possible to guarantee write data without input / output processing of the control information to the disk.

  The control device on the secondary side refers to the received write time and guarantees write data up to a certain time. As a result, it is possible not to leave an intermediate result of the transaction.

  It is an object of the present invention to minimize the number of data transfers by transferring write data directly between control devices when performing double writing between remote control devices, and to control the data. Even if the distance between the devices is increased, it is possible to provide a function of minimizing performance degradation and not leaving a result in the middle of a transaction. In addition, there is no need to execute disk input / output processing of control information, thereby achieving high performance.

  Examples of the present invention will be described below.

  First, the first embodiment will be described.

FIG. 1 shows an overview of the first embodiment. The configuration in the first embodiment includes one or more processing devices 100, one primary control device 104, one or more disk devices 105 connected to the primary control device 104, one secondary control device 109, and a secondary control device 104. It is composed of one or more disk devices 105 connected to the control device 109. The processing apparatus 100 may include a CPU 101, a main memory 102, and a channel 103. The primary control device 104 includes a control memory 107 and a cache memory 108. It is assumed that the control memory 107 and the cache memory 108 are nonvolatile. In addition, each may be duplicated for higher reliability. The cache memory 108 and the control memory 107 are constituted by semiconductor memories, and can be accessed by one to two digits faster than the disk device 105. The primary control device 104 performs data transfer between the processing device 100 and the disk device 105. Further, in the present invention, the primary control device 104 has a function of transferring data between the secondary control devices 109. Alternatively, the primary control device 104 may include one or more directors 106, and each director 106 may perform transfer between the processing device 200 and the disk device 205 and data transfer between the sub-control device 109. The internal configuration of the sub control device 109 is the same as that of the primary control device 104.

  Write data management information 113 corresponding to the write data 112 is created in the control memory 107.

  When the processing device 100 issues a write request 110 to the primary control device 104, the processing device 100 gives the write data 112 at the write time 111. The write time 111 represents the time when the write request 110 is issued, and the order of the write requests 110 issued by the processing apparatus 100 can be recognized from the write time 111. When there are a plurality of processing devices 100, the write time 111 can recognize the order of write requests 110 issued by different processing devices 100 using a common clock among the processing devices 100. Shall.

  FIG. 2 shows the configuration of the write data management information 113. Here, in particular, information directly related to the present invention will be described. In the present invention, when the processing apparatus 100 issues the write request 110, the designated disk is called a logical disk. The logical disk ID 120 is a logical disk number instructed by the processing apparatus 100 to write the corresponding write data, and is information included in the write request 110. In the present invention, the logical disk recognized by the processing apparatus 100 and the disk device 105 (physical disk) do not need to correspond one-to-one. As shown in FIG. 3, a logical disk may be defined on a plurality of disk devices 105. Further, redundant data may be included in a logical disk, and a RAID (Redundant Array of Inexpensive Disks) configuration may be adopted. The write address 121 is information included in the write request 110 and is information (for example, information such as an area of 1 MByte from the beginning of the logical disk) indicating an address in the logical disk to which the corresponding write data is written. The write data length 122 is information indicating the length of the corresponding write data, and is information included in the write request 110. All of the above information is information included in the normal write request 110. The write data pointer 123 is a pointer to the corresponding write data 112. The write time 111 has already been described. It is one of the features of the present invention that the write time 111 is given to the write request 110. The sub control device transfer necessity bit 124 is information indicating that the transfer of the write data 112 corresponding to the sub control device 109 is necessary.

  Another information included in the control memory 108 is the secondary logical disk number 114. This information is information that exists in correspondence with the logical disk of the primary control device 104, and is the number of the secondary logical disk that is a double-written pair of the corresponding logical disk, that is, the secondary control device that stores the secondary logical disk. 109 and a logical disk number in the secondary control device 109 of the secondary logical disk. Of course, it is assumed that a null value is entered in a logical disk having no double writing pair.

  The write data management information 113 is also included in the control memory 109 of the sub control device 109.

  The format may be the same as the write data management information 113 in the primary control device 104. However, it is assumed that the sub controller transfer required bit 124 is always off. Furthermore, it is the primary logical disk number 131. This information is information that exists for the logical disk of the secondary control device 104, and is the number of the primary logical disk that is a double-written pair of the corresponding logical disk, that is, the primary control device that stores the primary logical disk. 104 and the logical disk number in the primary controller 104 of the primary logical disk. Of course, it is assumed that a null value is entered in a logical disk having no double writing pair.

  When the primary write data receiving unit 130 of the primary control device 104 receives the write request 110 from the processing device 100, it starts its operation. First, the received write data 112 is stored in the cache memory 108. (Step 131) Next, the primary write data receiving unit 140 secures the write data management information 113 in the control memory 108 in response to the write request. (Step 132) Further, information such as the write time 111 included in the write request is stored in the secured write data management information 113, and the write data pointer 123 and the sub controller transfer necessary bit 124 are set. (Step 133) Finally, a completion report of the write request 110 is sent to the processing apparatus 100. (Step 134) Since there is no access to the disk device 105 in the above processing, a high-speed response is possible. The process of writing the write data 112 to the disk device 105 is executed later by the primary control device 104. Since this operation is an ordinary operation of the control device, it will not be described in detail.

  The primary write data transmission unit 140 of the primary control device 104 has a function of sending the write data 112 to the secondary control device 109. First, in the write data management information 113 in which the sub-controller transfer required bit 124 is set, the write data 113 with the earliest write time is referred to the corresponding secondary logical disk number 130 as 2 The data is sent to the sub-control device 109 where the overwritten pair exists. The length of the write data 112 and the address in the secondary logical disk to be written are specified with reference to the information in the write data management information 113. (Step 141) Next, a completion report from the sub-control device 109 is waited for. (Step 142) When the completion report is returned, the sub-controller transfer required bit 124 is turned off. (Step 143) Thereafter, the process returns to Step 140 to find the write data to be transmitted next.

  The secondary write data receiving unit 160 of the secondary control device 109 operates when the write data 112 is received from the primary control device 104. The processing content of the secondary write data receiving unit 160 is the same as that of the primary write data receiving unit 140 except that the secondary control device transfer necessary bit 124 is not set in the setting of the write data management information 113 (step 161). This is the same as the processing content.

  The secondary write data stage 140 of the secondary control device 109 has a function of writing the write data 112 to the disk device 105. First, in the write data management information 113, it is decided to write some write data 113 to the disk device 105 in the order of the earliest write time, perform appropriate calculations, and write the disk device. 105 and a write address are determined. Since this calculation method is a method used in normal RAID or the like, it will not be described in detail. (Step 171) Next, a plurality of requests for writing the write data 112 to the disk device 105 are issued in parallel to the disk device 105. (Step 172) Next, a completion report from the disk device 105 is waited for. (Step 173) After receiving the completion report of all the requests, the process returns to Step 170 to find the write data 113 to be next stored in the disk device 105.

  Since the transmission order of the write data 113 from the primary control device 104 to the secondary control device 109 is the order of the write time 111, the secondary control device 109 uses all the previous write data 113 as a reference based on a certain time. It is possible to create a state in which the data can be held and the write data 113 thereafter is not held at all. As a result, even if the primary control device 104 is destroyed, the secondary control device 109 can perform a recovery process that does not leave an intermediate result of the transaction. On the side of the sub-control device 109, control information such as the write data 113 and the write time 112 is held in a non-volatile semiconductor memory such as the cache memory 107 and the control memory 113. Is small.

  The contents described above may not provide sufficient performance because the transfer of the write data 112 from the primary control device 104 to the secondary control device 109 is serialized. FIG. 4 shows the operation when the transfer of the write data 112 from the primary controller 104 to the secondary controller 109 is executed in parallel. Each processing unit is different from the case where the transfer is serialized in that the primary write data transmission unit a300, the primary reference time transmission unit 170, the secondary reference time reception unit 180, and the secondary write data data stage a310. This is the data discarding unit 190 at the time of normal failure. Hereinafter, the processing flow of the primary write data transmission unit a300 will be described. First, in the write data management information 113 in which the sub-controller transfer required bit 124 is set, several write data 113 are referred to in order of the earliest write time, and the corresponding secondary logical disk number 130 is referred to. Then, the data is transferred in parallel to the sub-control device 109 in which the double writing pair exists. (Step 301) Next, wait for each completion report to be sent from the sub-control device 109. (Step 302) When all completion reports are returned, the sub controller transfer necessity bit 124 in the corresponding write data management information 113 is turned off. (Step 303) Thereafter, the process returns to Step 150 to find the write data 112 to be transmitted next.

  If the transfer of the write data 112 is executed in parallel, the order of the write times 111 of the write data 112 held on the sub-control device 109 side may come. Therefore, it is necessary to recognize the write time 111 that is a determination criterion for determining the write data 112 that the sub-control device 109 may destage. In this case, the write data 112 that may be destaged is the earliest write time 111 in the write data management information 113 in which the sub-controller transfer required bit 124 is turned on in the primary controller 104. Is the write data 112 having the write time 111 earlier than the reference time. This is because all the write data 112 having the write time 111 earlier than the reference time is held on the sub-control device 109 side. On the other hand, the write data 112 having the write time 111 after the reference time is still bad write data 112, and when the primary control device 104 is destroyed, these write data 112 Must not be destroyed and destroyed.

  The main reference time transmission unit 170 has a function of transmitting the above-described reference time that may be destroyed to the sub-control device 109. As described above, the reference time is the earliest write time 111 in the write data management information 113 in which the sub-controller transfer required bit 124 is turned on.

  The sub reference time receiving unit 180 stores the reference time received from the primary control device 104 in the control memory 108 as the de-stage permission time 185.

  FIG. 4 is a processing flow of the secondary write data stage unit a310 when the transfer of the write data 112 from the primary controller 104 to the secondary controller 109 is executed in parallel. The only difference from the processing flow shown in FIG. 1 is that the condition for selecting the write data 113 to be staged is that the write time 111 is earlier than the stage permission time 185. (Step 311).

  The normal failure data discarding unit 197 has a function of discarding the write data 112 having the write time 111 after the destination permission time 185 when the primary control device 104 is destroyed (step 191).

  Next, a second embodiment will be described.

  FIG. 5 shows an overview of the second embodiment. The difference between the second embodiment and the first embodiment is the number of primary control devices 104 and secondary control devices 109. In the first embodiment, the number of primary control devices 104 is one and the number of sub-control devices 109 is one. On the other hand, in the second embodiment, the number of primary control devices 104 is two or more and the number of sub-control devices 209 is one.

  When there are a plurality of primary control devices 104, a shift occurs in the write time 111 of the write data 112 received from each primary control device 104 on the sub-control device 109 side. The most recent write time 111 received from one primary control device 104 (eg, primary control device a), this time is time a, and the most recent write time 111 received from the other primary control device 104 (eg, primary control device b) Write time 111, and this time is time b. In this case, if the time b is earlier than the time a, there is a possibility that the primary control device a side holds the write data 113 that is more recent than the time a and earlier than the time b. There is. As described above, in order not to leave a result in the middle of a transaction, all write data 113 having a write time 112 before a certain reference time is guaranteed, and write data having a write time 112 after the reference time is guaranteed. All 113 need to be discarded. Therefore, the write data 112 having the write time 111 before the time a is the write data 112 that can be staged by the sub-control device 109.

  Correspondingly, the control memory 108 of the sub-control device 109 has a primary control device write permission time 500. The primary controller write permission time 500 is information existing for each primary controller 104 and stores the latest write time 111 received from the corresponding primary controller 104. Therefore, as described above, the write data 112 having the write time 111 before the reference time, with the earliest time among the primary controller write permission times 500 as the reference time, is sub-control device 109. This means that the write data 112 can be stored at the same time.

  Hereinafter, also in the present embodiment, the contents of each processing unit when the transfer of the write data 112 from one primary control device 104 to the sub control device 109 is executed in parallel will be described. Of course, the present embodiment is also effective in the case where the transfer of the write data 112 from one primary control device 104 to the sub control device 109 is serialized and executed.

  The processing flow of each processing unit of the primary control device 104 is the same as the processing flow in the first embodiment when the transfer of the write data 112 is executed in parallel (the processing of FIG. 3).

  Next, the processing flow of each processing unit of the sub control device 109 will be described.

  The processing flow of the secondary write data stage b510 in the second embodiment will be described. Here, the processing flow of the secondary write data stage 520 in the second embodiment will be described as different from the processing flow of the secondary write data stage 170 in the first embodiment. The processing content of the secondary write data receiving unit 510 in the second embodiment is that when the write data 112 to be staged is selected, the corresponding write time 111 is before all the primary controller write permission times 500. It is a point to check whether or not the write data 112 satisfying the condition is selected. (Step 511) Other than this, the processing flow of the secondary write data stage b510 in the second embodiment is the same as the processing flow of the secondary write data stage 170 in the first embodiment. .

  The sub reference time reception unit b520 sets the reference time received from the primary control device 104 to the primary control device write permission time 500 corresponding to the primary control device 104 that has transmitted the reference time.

  In the present embodiment, the write data 112 discarded by the correct failure data discard unit b530 does not satisfy the condition that the corresponding write time 111 is earlier than all the main controller write permission times 500. Write data 112. (Step 531)

  Next, a third embodiment will be described.

  FIG. 6 shows an overview of the first embodiment. The difference between the third embodiment and the second embodiment is also the number of primary control devices 104 and secondary control devices 109. In the third embodiment, the number of primary control devices 104 is two or more, and the number of sub-control devices 109 is one or more. In this case, it is not necessary that all pairs of the primary control device 104 and the secondary control device 109 are connected to each other.

  If there are a plurality of sub control devices 109, in order not to leave the middle result of the transaction, the reference time used when selecting the write data 112 to be staged is made common among the sub control devices 109. There is a need. This is because the database and journal may be distributed among the plurality of sub-control devices 109.

  In this embodiment, the master sub-control device 700 has a function of determining a reference time used when selecting the write data 112 to be destroyed. Therefore, the master control device 700 and the other sub-control devices 109 are connected by a data transfer path. If the data transfer path fails, the reference time used when selecting the write data 112 to be staged cannot be shared among the sub-control devices 109, so that the data transfer path is multiplexed. It is desirable to make it. In this embodiment, the master sub-control device 700 has the function of determining the reference time used when selecting the write data 112 to be stored. However, the function of determining the reference time is controlled by a specific sub-control. The present invention is effective even if a method of distributing to each sub-control device 109 without being provided in the device 109 (for example, a method in which each sub-control device 109 determines a reference time in turn).

  Corresponding to the above, the control memory 108 of the master secondary control device 700 has the secondary control device write time 701. The sub controller write time 701 is information corresponding to the sub controller 109 including the master sub controller 700. Each sub-control unit write time 701 is the earliest among all the sub-control unit write permission times 500 in the sub-control unit 109 by the master sub-control unit 700 at an appropriate cycle from each sub-control unit 109. Information (in the second embodiment, the sub-control device 109 uses a reference time when selecting write data).

  The master write time 702 is a time used as a reference when each sub-control device 109 selects the write data in the third embodiment. For the master write time 702, the master secondary control device 700 refers to all the secondary control device write times 701 at an appropriate cycle, selects the earliest time, and sets this time. All the write data 112 having the write time 111 before the selected time is held in the sub-control device 109. Therefore, by guaranteeing the write data 112 that satisfies this condition and discarding all the write data 112 that does not satisfy the condition, it is possible not to leave a result in the middle of the transaction.

  Hereinafter, also in the present embodiment, the contents of each processing unit when the transfer of the write data 112 from one primary control device 104 to the sub control device 109 is executed in parallel will be described. Of course, the present embodiment is also effective in the case where the transfer of the write data 112 from one primary control device 104 to the sub control device 109 is serialized and executed.

  The processing flow of each processing unit of the primary control device 104 is almost the same as in the second embodiment. Of course, the main reference time transmission unit 170 has a function of transmitting the reference time to each sub-control device 109 that transmits the write data 112. However, the reference time for transmission is the earliest among the write data management information 113 in which the sub controller transfer required bits 124 of all the write data 112 corresponding to the sub controller 109 that performs transmission are turned on. Is the write time 111.

  The processing flow of each processing unit of the primary control device 104 differs from that of the second embodiment in that the secondary control device 109 includes a secondary write time transmission unit 710, a secondary write data stage c720, and a normal failure. This is a point including a time data discarding unit c. The master sub control device 700 includes a master sub write time receiving unit 711, a master write time calculating unit 712, and a master sub write time transmitting unit 713730.

  The sub-write time transmission unit 710 sets the earliest time 180 among all the main controller write permission times 500 in the sub-control device 109 at an appropriate cycle, and the master sub-write time of the master sub-control device 700. The data is sent to the receiving unit 711. The sub write time transmission unit 710 of the sub control device 109 other than the master sub control device 700 uses the data transfer path between the sub control devices 109. The sub write time transmission unit 710 of the master sub control device 700 uses the communication means of the master sub control device 700.

  The master sub write time reception unit 711 sets the time received from the sub write time transmission unit 710 to the sub control device write time 701 corresponding to the sub control device 109 that has transmitted the time.

  The master write time calculation unit 712 refers to all the sub-controller write times 701 at an appropriate cycle, selects the earliest time, and sets this time as the master write time 702.

  The master secondary write time transmission unit 713 sets the master write time 702 at an appropriate cycle in accordance with requests from the secondary write data stage 720 and the normal failure data discard unit 730 of each secondary control device 109. Send the time. A data transfer path between the sub-control devices 109 is used for the sub-control devices 109 other than the master sub-control device 700. For a request from the master sub-control device 700, the master sub-write time transmission unit 713 uses the communication unit of the master sub-control device 700.

  The difference between the secondary write data stage 720 and the second embodiment is that when selecting the write data 112 to be staged, the secondary write data stage 720 receives a reference time from the master secondary write time transmitter 713, The point is that the write data 112 having the write time 111 earlier than this time is selected as the target of the destination (step 721).

The normal failure data discard unit c730 is different from the second embodiment in that when the write data 112 to be discarded is selected from the cache memory 107, the reference time is received from the master secondary write time transmission unit 713. However, the write data 112 other than the write data 112 having the write time 111 earlier than this time is selected as a discard target. (Step 731)
In this embodiment, the master control device 700 has received information necessary for calculating the reference time from the sub-control device 109, but may receive it from the primary control device 104 as shown in FIG. Good. In this case, the control memory 108 of the master secondary control device 700 has a master primary control device write time 800. The master primary control device write time 800 is information corresponding to the primary control device 104. The master primary control unit write time 800 includes all the master control units 700 including the sub control unit transfer necessity bits 124 in the on state in the primary control unit 109 from each primary control unit 104 at an appropriate cycle. This is information for receiving and setting the most recent write time 111 in the write data management information 113. At the master write time 702, the master secondary control device 700 refers to all the primary control device write times 701 at an appropriate cycle, selects the earliest time, and sets this time. The same applies in that the time used as the reference time at the time of discarding the data and data is the master write time 702.

The schematic diagram of a 1st Example. Write data management information format. FIG. 6 is a processing flowchart of a primary write data transmission unit when write data transfer from the primary control device to the secondary control device is executed in parallel. FIG. 6 is a process flow diagram of the secondary write data stage when the write data transfer from the primary control device to the secondary control device is executed in parallel. The schematic diagram of a 2nd Example. The schematic diagram of a 3rd Example. In 3rd Example, the master sub-control apparatus is a process schematic diagram when the information regarding write time is collected from the primary control apparatus.

Explanation of symbols

104 ... Primary control device 107 ... Control memory 108 ... Cache memory 109 ... Sub control device 111 ... Write time 112 ... Write data 113 ... Write data management information 124 ... Sub control device transfer required bit 130 ... Receipt of primary write data Unit 140 ... primary write data transmission unit 150 ... secondary write data reception unit 160 ... secondary write data stage unit 170 ... primary reference time transmission unit 180 ... secondary reference time reception unit 185 ... destination permission time 190 ... primary Failure data discard unit 300... Correct write data transmission unit a
310 ... Sub write data stage a
500... Primary controller write permission time 510... Secondary write data stage b
520 ... Sub-reference time receiver b
530... Data discard unit b at the time of normal failure
700 ... Master sub controller 701 ... Sub controller write time 702 ... Master write reference time 710 ... Sub write time transmitter 711 ... Master sub write time receiver 712 ... Master sub write time calculator 713 ... Master sub write time transmission Part 710 .. auxiliary write data stage part c
720 ... Data discarding unit c at the time of normal failure
800 ... Positive controller write time

Claims (2)

A first storage device system connected to the processing device and having a first control device, a first cache memory, and a first disk device;
A system connected to the first storage device system and having a second control device, a second cache memory, and a second storage device system having the second disk device,
The first control device receives a plurality of write data from the processing device, the write data received from the processing device, and other write data transmitted from the processing device to the first storage device system. And reference information indicating the relationship of the write order between the write data and the write data to the second control device,
The second control device stores the write data received from the first control device in the second cache memory, and stores the write data in the second cache memory based on reference information of the write data. A computer system, wherein write data that can be stored in the second disk device is selected from the stored write data, and the selected write data is stored in the second disk. A first storage system having a first storage device for storing first data to be processed by the first processing device and a first storage control unit for controlling the first storage device;
A second storage system having a second storage device for storing second data to be processed by the second processing device, a second storage control unit for controlling the second storage device, and
Connected to the first storage controller, receives first data transmitted by the first storage controller, and connected to the second storage controller, and the second storage controller A third storage control unit that receives second data to be transmitted; and a third storage device that stores the first data and the second data received by the third storage control unit. Three storage systems,
here,
The first storage control unit receives the first data received from the first processing device before transmitting the first data to the third storage control unit. A first completion report indicating that the data is stored in the cache memory of the first storage control unit and the first data is stored in the cache memory is returned to the first processing device,
The first storage control unit stores the first data in a first logical storage device provided on the first storage device when the first data is stored in the first storage device. Store data for
The second storage control unit receives the second data received from the second processing device before transmitting the second data received from the second processing device to the third storage control unit. A second completion report indicating that the data is stored in the cache memory of the second storage control unit and the second data is stored in the cache memory is returned to the second processing device,
In addition, when storing the second data in the second storage device, the second storage control unit stores the second data in a second logical storage device provided on the second storage device,
The third storage control unit is paired with the first logical storage device provided on the third storage device when storing the first data in the third storage device. When the first data is stored in a third logical storage device and the second data is stored in the third storage device, the first data is provided on the third storage device. A storage system, wherein the second data is stored in a fourth logical storage device paired with a second logical storage device.

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