JPH11265320A - External storage control device having remote transfer function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to continue real time transfer by suppressing I/O time monitor at the time of remote transfer of a general file or the like to transmit/receive data in an external storage control device having a remote transfer function to be used for a backup system for mutually transmitting/ receiving data between a master center and a sub-center by remote transfer. SOLUTION: In the case of remote transfer for a general file, an I/O time monitor suppressing mode is set up in a DX command parameter in a channel command word(CCW) issued from a master center side host 2. When a time monitor suppressing mode recognition part 13 recognizes the I/O time monitor suppressing mode set up in the DX command parameter, a resource management part 12 in a master center side remote FCU (external storage control device having a transfer function) 1 suppresses the time monitor of an I/O time monitoring part 14 and executes the writing of the requested general file in a volume 3 and remote transfer to a sub-center side remote FCU 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a backup system (hereinafter referred to as a sub-center) separately from an original business system (hereinafter referred to as a main center), and mutually transmits and receives data via a communication line. The function to perform
The present invention relates to an external storage control device (hereinafter, referred to as a remote FCU) having a remote transfer function capable of constructing an equivalent volume in a sub center system.

[0002]

2. Description of the Related Art FIG. 8 is a diagram showing a configuration example of a backup system including a main center and a sub center.

[0003] The main center has a business database (D
B) Host 9 composed of 90, CPU, memory, etc.
1, a remote FCU 92 and a volume 93, and the sub-center is a host 91 ', a remote FCU 9
2 'and volume 93'. Here, the volumes 93 and 93 'are so-called remote shadow volumes, and mutually equivalent data are stored by remote transfer of data.

The remote FCU 92 on the main center side and the remote FCU 92 'on the sub center side are connected by a communication line 94 such as a high-speed digital line. Host 9
1 and the remote FCU 92, and the host 91 'and the remote FCU 92' are connected by a channel interface, and the remote FCUs 92 and 92 'and the volumes 93 and 93' are connected by a SCSI interface. I have.

When the main center updates the database 90, an update log is stored in an update log buffer in the host 91. The host 91 executes the remote FC for the write processing with the backup of the update log.
When an I / O command is issued to the U92 requesting that the update log stored in the update log buffer be written to the volume 93, the remote FCU 92 writes the update log to the volume 93 and further via the communication line 94 The same data is transferred to the remote FCU 92 'on the sub center side. The remote FCU 92 'writes the received update log to the volume 93'. This makes volume 93 equivalent to 'volume 93,
The sub center backs up the main center.

[0006] Remote FCUs 92, 9 of primary / sub-centers
Data transmission and reception between 2 'are performed as follows. FIG.
11 are diagrams for explaining the operation of the remote FCU of the main / sub center in the conventional processing.

In the figure, (1) to (8), (11) to (1)
3) is an operation example of the remote FCU 92 on the primary center side, and (9) and (10) are remote FCUs on the secondary center side.
It is an operation example of 92 '. Here, the main center side host 9
1, a channel command word (CCW: Channel Command) issued to the main center side remote FCU 92.
d Word) command chain is DX (Define Exten
t) command, LR (Locate Record) command, WCK
It is assumed that the command is a D (Write Count, Key, Data) command.

(1) The activation of the difference log write instruction accompanying the update of the database (DB) 90 with the backup from the main center host 91 to the main center remote FCU 92 is performed by the DX of the channel command word (CCW).
Performed from command. The DX command is a command for designating an allowable range of execution of an access command subsequent to the DX command in advance.

(2) With this activation, the channel adapter (CA) notifies the resource manager (RM) that the activation has come from the channel. The RM checks the device status, and if there is no abnormality, allocates an area of the control table and starts time monitoring in one input / output (I / O) to prevent the difference log buffer from being exhausted.

In this time monitoring, a current time at the time of starting from the CA is recorded in a time stamp area of the control table, and a default 1I set in advance is recorded in the time stamp area.
Default I / O monitoring time obtained by adding the I / O monitoring time,
A method of monitoring by periodically comparing the actual timer value held inside the RM with the actual timer value is used.

Therefore, if the processing time exceeds the II / O monitoring time, the I / O monitoring time-out I / O
An O error is notified to the host 91 on the main center side, and the host 9
1 shifts the processing to accumulation operation. The accumulation operation is a method of storing data to be transferred in a storage area of the host 91 on the main center side and transferring the data at a time when the communication line 4 becomes available.

(3) Subsequently, the CA receives the LR command and its parameters. The LR command is information for a write process, and specifies an address of a target track, a search start address, and the like. The CA writes the DX command parameters and the LR command parameters in the control table, and has the cache function engine (CFE) allocate a cache area based on the information. At this time, an operation of reading the track onto the cache (hereinafter, referred to as staging) is performed.

The primary center CA uses the assigned cache area to receive the subsequent CCW WCKD command, execute a write process, and form a track on the cache.

(4) The CA records information necessary for starting data transfer in the control table, and requests the RM to start transfer. (5) When the above processing is completed, the CA temporarily disconnects from the host 91 in order to wait for the data transfer completion notification to the sub-center side.

(6) The RM activates the start of data transfer processing to the remote adapter (RA) in response to a transfer start request from the CA. (7) The RA reads the control table and starts transfer data information by starting the data transfer process from the RM. Based on the information, data is read from the cache area allocated from the CFE, and transmission processing is performed.

The transfer data to be transmitted to the communication line is in track units, and the RA divides the data in the target track into packets consisting of communication control data and actual data.
An operation number is added to each packet. Finally, a flag indicating the end is added to the packet, and the packet is transmitted to the sub center.

(8) When all data has been transmitted, the RA waits until a response packet indicating the end of processing is returned from the RA on the sub-center, which is the destination, within the set response monitoring time.

The data stored in the cache area on the main center side is appropriately written into the volume 93 on the main center side by a device adapter (DA). (9) The sub-center RA receives the first packet via the communication line 94. The secondary center RA further recognizes that it is a write process based on the communication control data of the packet while receiving the subsequently transmitted packet,
Based on this data, the data is written into the control table on the sub-center side, and a cache area is allocated from the CFE based on the information.

When a packet to which a flag indicating the last packet is added is recognized, it is determined that all the packets to be received from the main center RA have been received, and a process of writing the actual data of the received packet is started. To form tracks.

(10) The sub-center R that has completed the writing process
A sends back a response packet indicating the end of processing to the main center. After that, information such as the end position is written in the control table, and the RM is notified of the end of the writing process in the sub center.

The data stored in the cache area on the secondary center side is written to the secondary center volume by the secondary center DA as appropriate. (11) The primary center RA receives the response packet from the secondary center.

The validity of the response packet is determined by the operation number described in the response packet. After judging that the transfer control of the packet has been correctly performed to the sub-center, the end processing is performed according to the contents of the packet, and the RM is notified of the processing end.

When the sub center is notified of the occurrence of the error, the sub center reports the end of the processing to the RM by reflecting the content of the error. When a timeout of the response monitoring time is detected or when a transfer error is detected, data retransmission is performed based on the set number of retries.

(12) The RM rejoins with the CA and notifies the main center side of the host that the data transfer to the sub center has been completed. (13) The CA reports the processing end to the main center side host and notifies the RM of the processing end.

[0025]

The above-mentioned conventional method has the following problems. In the remote transfer according to the related art, the data to be remotely transferred is mainly a difference log accompanying a database update. Therefore, in consideration of the capacity of the update (difference) log buffer in the host, time monitoring in 1 I / O is performed to prevent update log buffer exhaustion, and 1 I / O issued from the host is performed.
If the time exceeds the I / O monitoring time, the host
Notify I / O error (I / O monitoring time-out)
In response, the host switched the processing to the storage operation.

However, when performing remote transfer for general files such as sequential files, it is not necessary to consider the capacity of the update log buffer. That is, in the case of a general file or the like, it is not necessary to monitor the I / O time.

Also, if the I / O time monitoring function operates in the remote transfer of general files as in the conventional method, one I / O issued from the host requires some time for I / O processing due to some circumstances. If the I / O monitoring time exceeds the required I / O monitoring time, the I / O that should normally end normally
, An I / O error (I / O monitoring time-out) is notified, and a problem may occur that the real-time transfer process is switched to the storage operation process.

An object of the present invention is to provide an I / O system for applying the function of a remote shadow volume to a general file or the like.
An object of the present invention is to provide a means for eliminating a problem caused by monitoring the O time.

[0029]

According to the present invention, in order to achieve the above object, a bit in a define extent (DX) command of a channel command word (CCW), which is a start command of a write process issued by a host, is used. /
Enable to set the mode to suppress O time monitoring,
The main feature of the remote FCU is to determine whether to monitor or inhibit the I / O time by judging this bit.

FIG. 1 is a block diagram showing the principle of the present invention.
The main center includes a main center-side remote FCU 1, a main center-side host 2, and a volume 3, and is connected to the sub-center by a communication line 4 such as a high-speed digital line. The sub-center includes a sub-center-side remote FCU 5, a sub-center-side host 6, and a volume 7. The volume 3 and the volume 7 are remote shadow volumes and hold mutually equivalent data.

The main center host 2 transmits the DX of the CCW to
A time monitoring suppression mode setting unit 21 for setting suppression information of the time monitoring function of the main center remote FCU 1 is provided. The main center side remote FCU1 is the interface control unit 1
1, a resource management unit 12, a transmission / reception control unit 15, and the like.

The interface control unit 11 is a means for controlling the interface between the main center side host 2 and the main center side remote FCU 1 and between the main center side remote FCU 1 and the volume 3. These are connected by, for example, a channel interface and a SCSI interface.

The resource management unit 12 manages resources in the subsystem relating to the basic operation.
/ O) input / output time monitoring unit 14 for monitoring time in
And a time monitoring suppression mode recognition unit 13 that recognizes the time monitoring suppression mode defined in the DX of the CCW and notifies the time monitoring suppression mode.

The transmission / reception control unit 15 is means for transmitting / receiving data to / from the sub-center side remote FCU 5 via the communication line 4. Although the case where there is one sub-center is shown, a backup system having two or more sub-centers may be used.

The present invention operates as follows. The time monitoring suppression mode setting unit 21 of the main center host 2 writes the remote transfer when writing data with backup to a general file that may cause a problem when monitoring the input / output time. The time monitoring suppression mode information is set in the DX bit of the CCW command.

When the main center-side remote FCU 1 receives a write command of remote transfer for a general file or the like with backup, the time monitoring suppression mode recognition unit 13 obtains the time monitoring suppression mode information of the CCW DX, and Without performing time monitoring by the input / output time monitoring unit 14,
The transmission / reception control unit 15 performs remote transfer processing of the general file. At the same time, the resource management unit 12 stores the general file in the volume 3 via the interface control unit 11.

The secondary center remote FCU 5 having received the general file via the communication line 4 writes the file to the volume 7 and notifies the main center remote FCU 1 of the transfer completion.

[0038]

Embodiments of the present invention will be described below. FIG. 2 is a diagram showing a configuration example of a remote FCU to which the present invention is applied. The hardware configuration is the same as the conventional one.

The channel adapter (CA) 101 is a module for controlling an interface with the channel 21 of the host 2 which is a host device. The resource manager (RM) 102 is a module that manages resources in a subsystem related to basic operations.

The table storage (TS) 103 is a memory used as a resource management table in the subsystem. The remote adapter (RA) 104 is a module that transmits and receives data to and from another remote FCU using a line controller.

The cache function engine (CFE) 105 is a module for managing a cache memory. Shared memories such as caches are collectively called a shared storage (SS) 106.

Control bus (C-BUS) 107
Is a route for each functional module to communicate with each other, and is used for transmitting and receiving control information between modules.

The device adapter (DA) 108 is a module for controlling an interface with a lower-level device.
In relation to the principle block diagram shown in FIG. 1, the channel adapter (CA) 101 and the device adapter (DA) 1
08 implements the interface control unit 11, the resource manager (RM) 102 implements the resource management unit 12, and the remote adapter (RA) 104 implements the transmission / reception control unit 15.

FIG. 3 is a diagram showing a configuration example of a DX command. From the main center host 2 to the main center remote FC
The DX command of CCW issued to U1 is a command for designating an allowable range of execution of an access command following this command in advance.

The DX command parameters are file mask information, global attribute, block length, Out
It consists of the number of Extent Check, asynchronous transfer attribute, conversion cylinder address, start track address, and end track address.

In the bit 1 of the asynchronous transfer attribute, an I / O time monitoring suppression instruction flag newly provided in the present invention is defined. When bit 1 of the asynchronous transfer attribute is “0”, I
I / O time monitoring is performed as usual, and when bit 1 of the asynchronous transfer attribute is “1”, I / O time monitoring is suppressed. In addition, the asynchronous transfer attribute () is bit2
, Remote order designation, bit 3 order guarantee mode, bit 4 I / O priority control mode designation, bit 5 batch transfer mode designation, bit 6 dynamic cache mode designation, and bit 7 DVCF cylinder conversion mode.

FIGS. 4 and 5 are diagrams for explaining the flow of processing for data transmission and reception between the primary and secondary centers when the time monitoring suppression mode is designated by the DX of the CCW. The sub-center remote FCU 5 is the main center remote FCU.
It is assumed that each module has a function similar to that of the module 1.

(1) to (8) are the main center side remote F
This is the operation of the CU. (1) From the main center host 2 to the main center remote F
A remote transfer write command for a general file or the like with a backup to the CU1 is activated from the DX of the CCW.

With this activation, the channel adapter (C
A) 101 receives the DX command parameter of CCW from the channel 21 and recognizes from the contents that the remote command is designated. At this time, by checking bit1 of the asynchronous transfer attribute () shown in FIG.
"O time monitoring suppression mode" is set in the control table.

(2) Subsequently, the CA 101 transmits the L of the CCW.
Receives R command and its parameters. LR is information for a write process, and specifies an address of a target track, a search start record address, and the like.

(3) The CA 101 calculates the DX parameter and L
The R parameter is written in the control table of the table storage (TS) 103, and a cache area is allocated from the cache function engine (CFE) 105 based on the information. At this time, if the track does not exist in the cache, it is once disconnected and
Staging is performed by the device adapter (DA) 108.

The CA 101 uses the allocated cache area to write the WCKD (Write Count, Ke
(y, Data) command, execute write processing, and form a track on the cache.

(4) The CA 101 records information necessary for starting data transfer in the control table, and requests the resource manager (RM) 102 to start transfer. (5) When the above processing is completed, the CA 101 temporarily waits for the notification of the end of the data transfer to the sub center,
And cut off.

(6) The RM 102 responds to the transfer start request from the CA 101 by the remote adapter (RA) 104.
At the same time, the start of the data transfer process is started, and at the same time, it is recognized from the control table that the transfer is the remote transfer and that the I / O time monitoring suppression mode is set. As a result, time monitoring is suppressed and transfer control is performed.

(7) The RA 104 starts the data transfer process from the RM 102 and reads the control table of the TS 103 to obtain information on the transfer data. Based on the information, data is read from the cache area allocated by the CFE 105 and transmission processing is performed.

The transfer data to be transmitted to the communication line 4 is in track units, and the RA 104 divides the data in the target track into packets composed of communication control data and actual data, and adds an operation number to each packet. Finally, a flag indicating the end is added to the packet, and the packet is transmitted to the sub center.

(8) When all data has been transmitted, the RA 104 waits until a response packet indicating the end of processing is returned from the RA 504 on the sub-center side that is the destination within the set response monitoring time.

The data stored in the cache area on the main center side is appropriately written to the main center volume 3 by the DA 108. Hereafter, the sub-center side R
A receives the packet. The following (9) and (10) operations of the remote FCU 5 on the sub-center side, and (11) to
The operation of the remote FCU 1 on the main center side (13) is the same as that of the prior art described with reference to FIG.

FIG. 6 and FIG. 7 are flowcharts of a program for I / O time monitoring control by the resource manager. In the main program shown in FIG. 6, when an interrupt occurs every 100 ms, a flag indicating that 100 ms has elapsed (hereinafter, referred to as a time monitoring flag) which is turned on by the interrupt destination program shown in FIG. 7 is checked. Perform time monitoring processing.

As shown in the flowchart of FIG.
When the resource manager (RM) 102 starts up from the channel (S1), it records the current time in the time stamp area of the control table (S2), and starts remote transfer processing (S3).

Next, the I / O time monitoring suppression instruction flag set in the control table is checked, and the current I / O is
It is determined whether the mode is the time monitoring suppression mode (S4). I /
If the O time monitoring suppression mode has been specified, step S
Proceed to 6.

If the I / O time monitoring suppression mode is not specified, it is determined whether the time monitoring flag is ON to perform the same time monitoring as in the conventional case (S5). This flag is set when a timer interrupt occurs every 100 ms.
The interrupt destination program executes the processing shown in FIG. 7 (S20, S2
This is a flag that is turned on to measure the elapsed time according to 1).

If the time monitoring flag is not on or if the I / O time monitoring suppression mode is specified, it is determined whether the remote transfer process has been completed (S
6) If not completed, S4 to S6 are repeated periodically until the remote transfer processing is completed. When the remote transfer process is completed, a completion report is sent to the channel (S
9) Return to START.

If the flag for monitoring the time is ON in the determination in step S5, the time-out time is further determined based on whether or not the actual timer value exceeds the time stamp record plus the default I / O monitoring time. Is determined (S7). The actual timer value is
The timer value is held inside the resource manager (RM) 102 and incremented by the interrupt destination program when an interrupt occurs. The default I / O monitoring time is calculated by the I / O calculated inside the resource manager (RM) 102. This is a timer value of the O monitoring time.

If the time-out time has not elapsed, the time monitoring flag is turned off (S8), and the process proceeds to step S6, where it is determined whether the remote transfer process has been completed. If the actual timer value has passed the time-out time, the I / O error of the I / O monitoring time-out is notified to the channel side (S10).

The interrupt destination program shown in FIG.
The following step S2 is performed when an interrupt occurs every 0 ms.
0 and S21 are executed, and after the process is completed, the process returns to the previous process. That is, the actual timer value inside the resource manager (RM) 102 is incremented (S20), and 1
A time monitoring flag indicating that 00 ms has elapsed is turned on (S21), and the process returns to the interrupt source (RETUR).
N).

[0067]

As described above, according to the present invention,
When remote transfer is performed between the main / sub center, information on the I / O time monitoring suppression mode is transmitted to the DX of the CCW so that I / O time monitoring can be suppressed for general files.
Provided in command parameters. As a result, the transfer process can be performed while a usable remote adapter exists, and the efficiency of the remote transfer process for general files can be improved without switching to the storage operation due to a timeout. .

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a diagram showing a configuration example of a remote FCU to which the present invention is applied.

FIG. 3 is a diagram illustrating a configuration example of a DX command according to the present embodiment.

FIG. 4 is a diagram illustrating a flow of data transmission / reception processing between a primary / sub center.

FIG. 5 is a diagram illustrating a flow of data transmission / reception processing between a primary / sub center.

FIG. 6 is a processing flowchart of I / O time monitoring control.

FIG. 7 is a processing flowchart of an interrupt destination program for time monitoring.

FIG. 8 is a diagram illustrating a configuration example of a backup system using a primary / secondary center.

FIG. 9 is a diagram illustrating a flow of a process of transmitting and receiving data between the primary and secondary centers according to a conventional method.

FIG. 10 is a diagram illustrating a flow of a process of transmitting and receiving data between the primary and secondary centers according to a conventional method.

FIG. 11 is a diagram for explaining a flow of data transmission / reception processing between a primary / sub center according to a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary center side remote FCU 11 Interface control part 12 Resource management part 13 Time monitoring suppression mode recognition part 14 Input / output time monitoring part 15 Transmission / reception control part 2 Primary center side host 21 Time monitoring suppression mode setting part 3 Volume 4 Communication line 5 Secondary Center remote FCU 6 Secondary center host 7 Volume

Claims (2)

[Claims] 1. A function of transmitting and receiving data between a first computer system and a second computer system via a communication line, whereby equivalent data is stored in the first and second computer systems. Means for recognizing a time monitoring suppression mode for monitoring whether or not to monitor an input / output time set in a data write request in the first computer system; Means for suppressing input / output time monitoring when the mode is a mode in which input / output time monitoring is not performed when data is remotely transferred to the second computer system in response to a data write request in the computer system. An external storage control device having a remote transfer function, comprising: 2. The external storage control device having a remote transfer function according to claim 1, wherein the recognition of the time monitoring suppression mode is performed based on information defined in a start command of a data write process in a channel command word. An external storage control device having a feature of remote transfer.