JPS605329A - Managing system of duplex disk - Google Patents

Abstract

PURPOSE:To obtain a duplex disk controlling device which can make message communication with no interruption of operation even when no information is written in one side disk device due to a trouble of a channel. CONSTITUTION:If a trouble occurs in a channel device CH0 after the device CH0 has written information (d) in a disk device DK0 and writing of the information (d) in the area (a) of another disk device DK1 becomes impossible, a central controller CC judges that the information (d) has not been written in the areas (a) of the DK0 and DK1 regardless of the information (d) written in the area (a) of the DK0. The central controller CC then connects the normal disk devices DK0 and DK1 with a normal channel CH1. When this connection is made, the disk devices DK0 and DK1 are treated in the same manner as in a case where the storing contents of the disk devices DK0 and DK1 coincide with each other and the central controller CC can continue normally its process even though either one of the disk devices DK0 and DK1 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION (al) Technical Field of the Invention The present invention relates to a message communication system equipped with a duplicated disk device, and particularly to a message communication system that prevents discrepancies in the storage contents of the duplicated disk device and improves the message communication system. This invention relates to a redundant disk management method that prevents interruption of operation as much as possible.

(bl Background of the Technology) A message communication system is equipped with a disk device for storing control information regarding a plurality of accommodated subscribers as well as messages sent by each subscriber. In order to improve the performance, it is necessary that the information be duplicated and that the same information be written in both disk devices.

fcl Prior Art and Problems Figure 1 is a diagram showing an example of a conventional duplex disk management method in this type of message communication system.
The figure shows another example of a conventional dual disk management system. In FIG. 1, duplicated disk units DKO and DKI can be connected to a central control unit CC via channel units CHO and CHI, respectively. When both channel devices CHO and CHI are normal, disk devices DKO and DKl are connected to channel device CHO, and central controller CC sends information d to area a of disk device DKO via channel device CHO. Then, an attempt is made to write the same information d to the same area @a of the disk device DKI via the channel device CHO. In such a case, if a failure occurs after the channel device CHO finishes writing the information d to the disk device DKO, and the information d cannot be written to the area a of the disk device DKI, the channel device CHO will write the information d to the disk device DKO.
The central controller CC receives the report of the failure and reconnects the normal disk units DKO and DKI to the channel unit CHI, disconnects the affected channel unit CHO, and thereafter connects the disk units DKO and DKI via the channel unit CHI. Use DKI. However, although information d is written in area a of disk device DKO, information d is written in area a of disk device DKO.
Since information d is not written in area a of , there is a possibility that central control unit CC may produce an undesirable processing result when disk device DKI is used.

In addition, in FIG. 2, if the disk device DKI is disabled for a certain period of time due to a failure and the central control unit CC writes information only to the disk device DKO, the storage contents of the disk device DKI will be changed to the disk device DKO. The contents of the memory will be different. To start using the disk device DKI again in such a state, the central controller CC
For example, the storage contents of disk devices DKO and DKI can be copied by reading the storage contents of disk device DKO via the channel device CHO and writing them to the same area of the disk device DKI via the channel device CHO. try to match.

Now the central control unit CC is the storage area R of the disk device DKI.
If a request to write information d to area a occurs after copying up to 1, the central control unit CC writes information d to area a of disk device DKO that is available and prohibits its use. Since no writing is performed to the disk device DKI in the state, even if copying to the remaining storage area R2 of the disk device DKI is completed, the storage contents of the disk device DKI are the same as the storage contents of the disk device DKO and information d. I won't be able to do it. In order to prevent such discrepancies, the central control unit CC prohibited writing of information to either disk device DKO or DKI during copying, so the message communication system had no choice but to suspend operation during that time. It disappears.

As is clear from the above explanation, in the conventional duplex disk management system, one channel device (for example, CH
Even if information is not written to the disk device (for example, DKI) due to a failure in disk device DKO, the central controller CC regards the disk device DKI whose storage contents no longer match that of the disk device DKO as normal, and writes the other disk device DKI to the other disk device DKO. There is a disadvantage that it is continuously used via a channel device (for example, CHl), and writing of information to either disk device DKO or DKI is prohibited while the storage contents are being copied between disk devices DKO and DKI. As a result, the message communication system had the disadvantage of interrupting its operation.

(dl Purpose of the Invention The purpose of the present invention is to eliminate the drawbacks of the conventional duplex disk management method as described above, and to operate the duplex disk device without error even when information is not written to one of the disk devices. It is another object of the present invention to realize a means for enabling the message communication system to continue operating even while the storage contents are being copied between duplicated disk devices. be.

(fl) Structure of the Invention This object comprises a central control unit and a duplicated disk device, and the central control device writes information to the duplicated disk device and reads information from any of the disk devices. This is achieved by determining that the information has not been written to any of the duplex disk devices when an abnormality is detected in the writing of information to either of the duplex disk devices in the message communication system. and the other purpose is that in the message communication system, when the storage contents of one of the disk devices are being copied to the other disk device whose use is prohibited, information written to the one disk device is copied to the other disk device. This is achieved by also writing to the disk device.

g) Examples of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram showing a duplex disk management system according to one embodiment of the present invention, and FIG. 4 is a diagram showing a duplex disk management system according to another embodiment of the invention. Note that the same reference numerals indicate the same objects throughout the figures. In Figure 3,
Disk units DKO and DKI are channel units CHO
and the central controller CC is connected to the channel device CH.
The information d is written to the area a of the disk device DKO via the channel device DKO, and then an attempt is made to write the same information d to the same area a of the disk device DKI via the channel device CHO. In such a case, the channel device CHO is the disk device DK.
If a failure occurs after writing information d to O, and information d cannot be written to area @a of disk device DKI,
The central control unit CC receives a report of a fault in the channel device CHO from the channel device CHO, and even though information d has been written to the area a of the disk device DKO, the central control unit CC If so, it is determined that the information d has not been written. From now on, the central controller C
C reconnects the normal disk units DKO and DKI to the channel unit CF (1), disconnects the affected channel unit CHO, and uses the disk units DKO and DKI via the channel unit CHI.As a result, the disk The storage contents of devices DKO and DKI are treated as if they match, and the central controller CC
Normal processing results when either KO or I) Kl is used.

In addition, in FIG. 4, when the central controller CC starts using the disk device DKI again, which has been prohibited for a certain period of time, the central controller CC uses the disk device tD.
Starts copying the stored contents of KO to disk device DK. If a request to write information W1d to area a occurs while the central controller CC has copied up to the storage area R1 of the disk device DKI, the central controller CC will copy the disk device DKO that is available for use. At the same time, the same information d is also written to the same area a of the disabled disk device DKI. As a result, when copying to the remaining storage area @R2 of the disk device DKI is completed, the storage contents of the disk device DKI are transferred to the disk device DKI.
The stored contents of KO match exactly, and the disk device DKI becomes usable immediately.

Also, there is no need to interrupt the operation of the message communication system during copying.

As is clear from the above description, according to this embodiment, when information is not written to the disk device (for example, DKI) due to a failure in one channel device (for example, CHO), the central control device CC Since it is determined that no information has been written to the disk device DKO, the disk device DK
The stored contents of O and DKl are used in the same way as if they matched, and while the stored contents are being copied between disk devices DKO and DKl, information can also be written to disk devices DKO and DKI, and the message communication system is There is no need to interrupt operation.

Note that FIGS. 3 and 4 are only one embodiment of the present invention, and for example, failures are not limited to those occurring in the channel device CHO, and may also occur in the channel device CHI. However, even in such a case, the effects of the present invention do not change. Also, copying of memory contents is done using the disk device DKO.
It is not limited to what is done from the disk device DKI to the disk device DKI, and from the disk device DKI to the disk device DKO.
Although it is also considered that the method is carried out separately, the effects of the present invention do not change even in such a case. Furthermore, it goes without saying that the configuration of the message communication system is not limited to that shown in the drawings.

(gl) Effects of the Invention According to the present invention, in the message communication system, even if information is not written to one of the disk devices, it is possible to use a duplicated disk device without error. Furthermore, the message communication system can continue to operate even while the stored contents are being copied between the duplicated disk devices, and the reliability and availability of the message communication system are improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional duplex disk management method, FIG. 2 is a diagram showing another example of a conventional duplex disk management method, and FIG. 3 is a diagram showing a duplex disk management method according to an embodiment of the present invention. FIG. 4 is a diagram showing a duplex disk management system according to another embodiment of the present invention. In the figure, a, R1 and R2 are areas, cc is a central control unit, CHO and CHI are channel devices, d is information, and DKO and DKI are disk devices. 1 Rod (Figure 4 and /) Rod 2 Concave

Claims (1)

[Scope of Claims] (]) comprising a central controller and a duplicated disk device, the central controller writes information to the duplicated disk device and reads information from either disk device; In the communication system, when an abnormality is detected in the writing of information to one of the duplicated disk devices, it is determined that the information has not been written to any of the duplicated disk devices. Duplex disk management method. (2) A message communication system comprising a central controller and a duplicated disk device, wherein the central controller writes information to the duplicated disk device and writes information to one of the disk devices without reading information from either disk device. 1. Duplex disk management characterized in that when the storage contents of the disk device are being copied to the other disk device whose use is prohibited, the information written to the one disk device is also written to the other disk device. method.