JPS58219656A - Double writing magnetic disk controller - Google Patents

Abstract

PURPOSE:To perform double writing processing successively even if a fault occurs to a data bus, by providing a couple of directors which enable the double writing to data buses extending from a CPU to a main and a subordinate magnetic disk files. CONSTITUTION:A request to update data is supplied from the CPU14 to one director 22A (or 22B). Then, updated data is recorded on the main magnetic disk file 10A through one data bus system and a magnetic disk driving device 18-1. At the same time, the request to update data is written in both buffers of both directors 22A and 22B at the same time and also written in both queue buffers. Then, the other free director 22B (or 22A) searches a queue buffer to write the updated data in the subordinate magnetic disk file 20B through a driving device 18-2. Consequently, even if a fault occurs to the director 22A or 22B, the updated data is obtained from the other buffer and the data update of the subordinate disk file 20B is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention provides a magnetic disk control device that injects updated data into a magnetic disk file in response to a data update request, in particular, injects the same updated data into primary and secondary magnetic disk files in response to a data update request. This invention relates to a dual-write magnetic disk control device that writes separately.

BACKGROUND OF THE INVENTION In recent years, magnetic disk devices have become more and more fixed media and more popular, and are therefore widely used as online files.

When a magnetic disk is used as a large-capacity online file like this, conventionally data was written on the magnetic disk in one go.

In the event of a failure in a magnetic disk device, create a backup file in advance in units of -1 day, week, etc., save it, and load this backup file to another magnetic disk device when a failure occurs in the online magnetic disk device. It was necessary to catch up with the journal file from the day before and execute that process to recover from the failure. Therefore, in the past, there has been a problem in that when a failure occurs in an online magnetic disk device, an enormous amount of time and effort is required to recover from the failure.

Therefore, conventionally, a dual writing method has been considered in which the magnetic disks used as online files are duplicated and the busy and updated data are written separately on the magnetic disks.

The above methods include those using software and those using hardware. Among these, the method using software executes the above-mentioned double writing in the central processing unit, which increases the software overhead and reduces the performance of the entire system. However, in this respect, dual writing processing by hardware is effective.In particular, methods in which dual writing processing is performed on the magnetic disk controller side are difficult to solve by combining the primary and secondary magnetic disk files. It is suitable in that it can be placed under the control device at will.

However, in conventional systems in which the above-mentioned double write processing is performed on the magnetic disk control unit side, the magnetic disk file is simply duplicated and the double write processing is performed, and the central processing unit writes the magnetic disk file. The data bus system leading to the system is a single system, and when the data bus fails, the above-mentioned double write processing is not performed and the double write data cannot be stored on the magnetic disk. There was a problem.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems.
The purpose is to provide a dual-write magnetic disk control device that can continue to perform the dual-write processing even if a failure occurs in the data bus from the central processing unit to the magnetic disk device. In order to achieve this, the present invention has a pair of directors connected to two data bus systems extending from the central processing unit to the magnetic disk file, and one of the directors is connected to two data bus systems extending from the central processing unit to the magnetic disk file. The director transfers the updated data from the central processing unit to the positive magnetic disk file via either data bus system, stores the updated data, and causes the other director to store the updated data, and any director stores the updated data. The system is characterized in that the update data that has been updated is sent to the sub-magnetic disk file via either data bus system, and the update data can be written twice by any of the directors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a dual write magnetic disk control device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a dual write magnetic disk control device according to the present invention. FIG. 2 shows the internal block configuration of the dual-write magnetic disk controller in the system shown in FIG. 1.

In FIG. 1, the central processing unit 14 is connected to the upper side of the dual-write magnetic disk controller 10 via a channel device 12412B. A large number of magnetic disk drive devices 1B-1, 1B-2, . . . are connected via a large number of magnetic disk connection devices 16A% 16B.

The magnetic disk drive device 1B-1 can write updated data to the primary magnetic disk file 2CL4, and the magnetic disk drive device 18-2 can write the same updated data to the secondary magnetic disk file 20BK. .

As described above, from 1 central processing unit 14 to channel device 12
, 4, 12B dual-write magnetic disk controller 1a% In the present invention, there are two data bus systems that reach the primary and secondary magnetic disk files 20AzoBK via the disk drive device xaj4S16B.

Further, in the present invention+, the dual-write magnetic disk control device 10 has a pair of directors 22422B, and the directors 22,
4.22B is connected to the above two data path systems and configured as follows.

In this embodiment, the directors 22422B are connected to the central processing unit 1 through channel switches 24A and 2J, respectively.
Connected to 4. In addition, this channel switch 2
4, 4.24B can switch the director 22A% 22B to the central processing unit of another channel.

Further, in the present invention, the directors 22A and 22B can independently perform the dual writing, and therefore the dual writing magnetic disk control device IO of this embodiment is configured as follows.

In FIG. 2, the dual-write magnetic disk control device 10 includes a channel switch 24A% 24B1, a disk connection device 164, and data buses 26, 4 connected to
．． 26B is provided to ensure two systems of data bus systems from the central processing unit 14 to the primary and secondary magnetic disk files 2OA and 20E IfC.

Each director 22A of the dual-write magnetic disk controller IO
K is 2 data buffers 2BA-input 287 nippet 5ae
B-'L, 28B-2 is provided, and the director 2
The data buffers 28A-2 of No. 24 and the data buffers 28B-2 of the director 22B are connected to the data bus 26B via a data bus 26C-1, respectively. These data buffers 28A-2 and 28B-2 can store updated data from the data bus zeA,
The stored update data can be respectively sent onto the data bus 26A2eE. See you again 1' hi
7 y 2BA-1, 28B-2 Mochi-fi Lotus 2f
A data buffer 28A-28B is connected to the data bus 26AaeB via C-4 and is capable of storing updated data from the IFi data bus 26B;
The updated data can be sent to each data bus z6A2eBK.

The directors 22A and 22B have a control memory 3o4 soB storing access control data for the data buffers 2B and 4.28B, and a control memory 3A.
The data is imported from SsoB via the data bus 32 for double write control, and the write order of updated data is controlled by the imported data.
Four reductions 34B are provided respectively.

A preferred embodiment of the present invention has the above configuration, and its operation will be explained below.

When a data update request is given from the central processing unit 14 to one of the directors 22 via the channel device 12,
The director 22 via its magnetic disk connection device 16, that is, via any data bus system,
Update data to magnetic disk drive g! , 1B-1, and causes the update data to be recorded in the active magnetic disk file 20A. At the same time, the director 22 writes the same update data to the data buffers of both directors 2g2SJ for 2 days, 4.28BK, and when the writing is completed, the data update request is sent to the data buffers 34A% of both directors 2g2SJ.
Queue to rs4B.

After that, the director-free director 22, which is not performing the '10 operation, searches for a data update request stored in its key buffer 34, and controls the magnetic disk drive unit 18-2 in accordance with the update request. , writes the updated data given from the central processing unit 14 to the secondary magnetic disk file 2oB.

Here, if a fault occurs that makes the director 22422B (in the dual-write magnetic disk control device lo) inoperable, and the other operable director 22 becomes director-free, the data of the director 22 will be (Update data is taken out from the software 28 onto the data bus 26, and the update data is transferred to the magnetic disk drive 18-2.
is applied to update the data in the sub magnetic disk file 20B.

An example of a processing operation for more than one busy day will be explained with reference to FIG.

In FIG. S, from the central processing unit 14 to the director 22
When a data update request is issued for the positive magnetic disk file 20A to j4, the direc- tor 22A performs positioning of the positive magnetic disk file 20A (D),
While writing data, the data buffer 28A
-2% Write the transfer data to 28B-2.

After writing of the magnetic disk file 1aoA is completed, the director 22A positions the auxiliary magnetic disk file aoB when it is free, and writes data in the data buffer 28B-2.

If a failure occurs in the director 22B while the above-mentioned data is being written, the function of the director 22B stops and data writing cannot be continued. However, in the case of Jin, the director 22A starts operating. The records and codes of the auxiliary magnetic disk file 20B are positioned, data is taken out from the data buffer 28A-2, and the data is written. In this way, even if a failure occurs in one of the directors 22, the same data will be written to the primary and secondary magnetic disk files 20, 4%, 20BK, and this dual writing process will not be interrupted. Data buffers 5.1 and 34 are separately provided in both directors 22 and 22B, and both directors 22A and 22B can use them independently.
Even if there is a deviation in the 0 order, the updated data can be transferred from the data buffer 28 to the sub magnetic disk file 20B by one of the directors in the director free order. Therefore, the system throughput time is reduced. is shortened.

According to the present invention, the central processing unit or
Since a pair of directors capable of performing the above-mentioned dual writing are provided in the two data bus systems extending from the main and secondary magnetic disk files independently, the dual writing operation is possible even if a failure occurs in one of the directors. On the other hand, the updated data can be written to the secondary magnetic disk file processing to continue double writing of the updated data, thus improving the reliability of the system.

Further, according to the present invention, since the double write operation can be performed without changing the software, the overhead of the software does not increase.
There is no reduction in system performance.In addition, data is transferred from the data buffer or channel device of each director to the central processing unit, or from the magnetic disk drive side to the data path sofa of each director. Therefore, the device of the present invention can also be used as a disk cache control device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a system using a dual-write magnetic disk controller to which the present invention is applied, FIG. 2 is an internal block diagram of the dual-write magnetic disk controller shown in FIG. 1, and FIG. FIG. 3 is an explanatory diagram of overwrite processing operation. 10... Dual write magnetic disk control device 14 ・
...Central processing unit 20.4...Main magnetic disk file 20B...Sub magnetic disk file 22422B...Director 26...Data buffer 34...Keeper 7a 1 Figure 72

Claims (1)

[Scope of Claims] <11 It has a pair of directors connected to two data bus systems extending from the central processing unit to primary and secondary magnetic disk files, and one of the directors is activated by a data update request from the central processing unit. The update data from the central processing unit is transferred to the positive magnetic disk file via the data bus system of What is claimed is: 1. A dual-write magnetic disk control device, characterized in that the dual-write magnetic disk controller sends the data to a sub-magnetic disk file via any data bus system. (2) The apparatus according to claim (1), wherein each director includes a data buffer for storing update data and a keypad software for controlling the write order of the update data. Heavy-duty magnetic disk device.