JPH0536197A - Double write magnetic disk sub system - Google Patents

Abstract

PURPOSE:To improve the processing of a magnetic disk sub system in a fixed time by always accessing a magnetic disk ending faster seeking operation by a magnetic disk control device. CONSTITUTION:By the magnetic disk control device 100, the commands of seek operation and orientation operation to a target cylinder are outputted. By a control circuit 210, the seek operation to the same cylinder and the orientation operation to the same record are instructed simultaneously to the magnetic disks 230 and 240. The circuit 210, upon receiving an ending report, e.g. from the disk 230, informs the device 100 of it. By the device 100, a write command to a signal line 101 and a write data to the signal line 102 are sent. The outputted write data is written by the disk 230. Simultaneously, the write data is written by a write buffer 220. Then, when the seek operation, etc., is ended, the data of the buffer 220 is written by the disk 240.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual-write magnetic disk subsystem, and more particularly to a DMA transfer system with a dual-write magnetic disk.

[0002]

2. Description of the Related Art As a conventional dual-write magnetic disk subsystem, there is a dual-write magnetic disk subsystem in which the same information is sequentially written into two magnetic disk devices by software.

[0003]

In this conventional dual-write magnetic disk subsystem, the software sequentially writes the same information to two magnetic disk devices.
There is a problem that the processing time from the software to the magnetic disk device becomes long and the efficiency of the information processing device is lowered.

An object of the present invention is to provide a dual-write magnetic disk subsystem that solves the above problems.

[0005]

In order to achieve the above object, a dual-write magnetic disk subsystem according to the present invention is an information processing system including a magnetic disk control device and a magnetic disk device. First and second magnetic disks in the magnetic disk device; a write buffer for storing write data transferred from the magnetic disk control device; and write data transferred from the magnetic disk control device, or A first selector for selecting any one of write data stored in the write buffer and outputting the selected write data to the first magnetic disk; write data transferred from the magnetic disk control device; or the write buffer Second selector for selecting whether the write data is stored in the second magnetic disk and outputting it to the second magnetic disk A third selector for selecting either the read data from the first magnetic disk or the read data from the second magnetic disk and transferring the selected read data to the magnetic disk controller; and the magnetic disk controller. Command of the seek operation to the first and second magnetic disks and the positioning operation to the target record, and which one of the magnetic disks reports the end of the seek operation and the positioning operation to the target record first. A control circuit that determines whether or not the selector controls and the seek operation to the magnetic disk control device, the end report of the positioning operation to the target record, and the output instruction of the write data stored in the write buffer, Read / write to the first magnetic disk according to an instruction from the control circuit.
It has a read / write control circuit for instructing a write operation, and a read / write control circuit for instructing a read / write operation to the second magnetic disk in response to an instruction from the control circuit.

[0006]

According to the present invention, the magnetic disk control device always accesses the magnetic disk whose seek operation is completed earlier, without the software or magnetic disk control device being aware of double writing.

[0007]

The present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a dual write magnetic disk subsystem according to Embodiment 1 of the present invention.

In FIG. 1, 100 is a magnetic disk controller (hereinafter referred to as DKC), 101 is a signal line for transferring an instruction, 102 is a signal line for transferring write data, and 200 is a magnetic disk device.

Reference numeral 210 denotes a command for receiving a command from the DKC 100, a command for a seek operation and a positioning operation (hereinafter referred to as orientation) to a target record, a seek operation and management of an end report of the orientation, and the DKC 10.
This is a control circuit for controlling switching of 0 and the magnetic disk to be accessed.

Reference numeral 211 is a selector switching instruction signal line, 212 is a signal line for instructing seek operation and orientation, 213 is a write buffer control signal line, and 214 is a signal line for reporting the end of seek operation and orientation to the DKC 100.

220 is a write buffer for storing write data from the DKC 100, and 221 is a write buffer 2.
20 is a signal line for outputting the data stored therein, 230 is a magnetic disk (hereinafter referred to as DKU-A), and 231 is DK
It is a signal line for transferring the read data output from the U-A 230.

Reference numeral 232 is a signal line for reporting the state of the DKU-A 230, and 240 is a magnetic disk (hereinafter DKU-B).
, 241 is a signal line for transferring the read data output from the DKU-B240, and 242 is a DKU-B.
Signal line for reporting 240 status, 250 for DKC1
00 or write data from the write buffer 220.

251 is an output signal line of the selector 250, 260 is either the DKC 100 or the write buffer 220.
, 261 is an output signal line of the selector 260, and 270 is a selector for selecting read data from the DKU-A or DKU-B.

271 is an output signal line from the selector 270, 280 is a read / write control circuit for controlling access to the DKU-A, 281 is a signal line for sending read / write command information, and 290 is a DKU-B. A read / write control circuit for controlling access, and 291 is a signal line for transmitting read / write command information.

Next, the operation will be described.

First, the write operation will be described.

The DKC 100 outputs a command for a seek operation to a target cylinder and an orientation operation command to the signal line 101.

The control circuit 210 includes DKU-A230 and DK.
The U-B 240 is instructed from the signal line 212 to simultaneously perform a seek operation to the same cylinder and an orientation operation to the same record.

The DKU-A 230 and the DKU-B 240 respectively perform seek and orientation operations, and when the orientation to the target record is completed, the signal lines 232 and 242 report the end of seek and orientation to the control circuit 210.

In this example, it is assumed that the DKU-A230 reported earlier seek and orientation.

When the control circuit 210 receives the completion report of the signal line 232, it sends a completion report of the seek and orientation to the DKC 100 from the signal line 214.

When the DKC 100 recognizes the end of seek and orientation, it sends a write command to the signal line 101 and a write data to the signal line 102.

The control circuit 210 instructs the signal line 211 to the selector 250 to select the write data to be output to the signal line 102, and the selector 260 to instruct the selector 260 to select the write data to be output to the signal line 221. Then, the write operation is instructed to the read / write control circuit 280.

The read / write control circuit 280 outputs a write command from the signal line 281 to the DKU-A230, and the DKU-A230 writes the write data output to the signal line 251.

At the same time, the write buffer 220 stores the write data output to the signal line 102. DK
When the U-B 240 reports the end of seek and orientation to the control circuit 210 from the signal line 242, the control circuit 210 sends the write buffer 22 from the signal line 213.
0 is instructed to output the stored write data to the signal line 221.

The control circuit 210 also instructs the read / write control circuit 290 to perform a write operation. DKU-B2
Reference numeral 40 writes the write data output to the signal line 261.

In this way, the DKC 100 seeks,
Writing is performed only to the DKU-A230 whose orientation is completed early, and double writing is performed without recognizing the DKU-B240.

Next, the read operation will be described. Similar to the write operation, the DKC 100 directs seek and orientation from the signal line 101 to the target cylinder.

The control circuit 210 controls the signal lines 212 to D
Seek and orientation are simultaneously instructed to the KU-A230 and DKU-B240.

The control circuit 210 switches the selector 260 from the signal line 211 so as to select the read data of the disk which has reported the end before the DKU-A230 or DKU-B240.

Further, the read operation is instructed from the read / write control circuit of the magnetic disk selected by the selector 260, and the read data is output to the signal line 271.

In this way, the same data written in the same cylinder and track can be read by the DKC 100 from the magnetic disk whose seek and orientation are completed earlier.

(Second Embodiment) FIG. 2 is a block diagram showing a second embodiment of the present invention.

In FIG. 2, in addition to the configuration of the first embodiment, in the present embodiment, a write operation end report from the magnetic disks 230 and 240 to the control circuit 110 and a failure report during the write operation are monitored, and a single operation is performed when a failure occurs. A state monitoring circuit 2300 for controlling the read / write control circuits 280 and 290 to perform a write operation, and a write operation completion report detected by the state monitoring circuit 2300 and a double write degraded state due to a failure occurring during the write operation are controlled by a magnetic disk. And a notification circuit 2310 for notifying the device 100. Also, 23
A notification signal line 11 is output from the notification circuit 2310 to the DKC 100.

In the write operation of the first embodiment, the control circuit 210 of the state monitoring circuit 2300 causes the DKU-B24.
It is monitored whether or not a failure report of writing from 0 is detected.

In the notification circuit 2310, the control circuit 210 has the DK
It is monitored whether a write end report is received from the U-A230 or DKU-B240 or a failure during writing is detected.

When the control circuit 210 first receives the write end report (in this example, the DKU-A 230 side), the notification circuit 2310 sends the signal line 2311 to the DKC 100.
The write operation end is reported to the DKC100, and the end report of the DKU-B240 is not reported to the DKC100.

When the control circuit 210 detects a failure report during writing of the DKU-B240, the status monitoring circuit 2300
From the signal line 211 to the selector 250 and the selector 26 so that only the DKU-A230 can read and write thereafter.
0, an instruction is given to the selector 270, and an instruction is given only to the read / write control circuit.

The notification circuit 2310 reports to the DKC 100 from the signal line 2311 that it is in the double-write degraded state and that the single write operation will be executed thereafter.

In this way, the write operation time of the DKU 100 can be shortened, and even if a failure occurs in one of the magnetic disks, it can be operated in single writing.

According to the present embodiment, the write operation end report is sent to the magnetic disk subsystem of the first embodiment only by the end of the write operation. Therefore, the write operation to the software or the DKC is performed. Processing time can be shortened.

Further, even if a failure occurs in one of the magnetic disks, the processing can be continued by single writing, so that the reliability of the magnetic disk subsystem can be improved.

(Third Embodiment) FIG. 3 is a block diagram showing a third embodiment of the present invention.

In the present embodiment shown in FIG. 3, in addition to the configuration of the first embodiment, a selector 27 is provided in the magnetic disk device 200.
The read data output from 0 is output to the magnetic disk control device 100, and the control circuit 21 determines whether the read data is enabled.
Driver 3340 controlled by 0 and selector 2
It has a selector 3320 which selects either the read data output from 70 or the write data transferred from the magnetic disk control device 100 according to an instruction from the control circuit 210 and outputs the selected data to the write buffer 220. An output signal line of the 3221 selector 3320, and a driver 3 3215
Enable signal line to 340.

In the write operation of the first embodiment, DKU-
A case where the write operation cannot be executed normally by either A230 or DKU-B240 will be described.

In this example, it is assumed that the DKU-B240 could not write normally.

The control circuit 210 causes the DKU-B240 to write normally, seek to a record,
Orientation is DKU-A230, DKU-B2
Execute for 40.

When the end of seek and orientation is reported from the signal line 232, the control circuit 210 enables the driver 3340 from the signal line 3215, selects the signal line 221 from the signal line 211 to the selector 260, and the selector 270. Signal line 231
Read data, the selector 3320 selects read data on the signal line 271, and the read / write control circuit 280 is instructed to perform read operation.
The write command is issued to the write buffer 220 from 3.

Therefore, the read data from the DKU-A 230 is stored in the write buffer 220.

Next, when the DKU-B 240 reports the end of seek and orientation, the control circuit 210 stores a write operation instruction in the read / write control circuit 290 and stores it in the write buffer 220 from the signal line 213. It is instructed to output the data to the signal line 221. The DKU-B240 can write the data stored in the write buffer via the selector 260.

In this way, copying can be performed only within the magnetic disk subsystem.

In the magnetic subsystem according to the present embodiment, copying can be performed in the magnetic disk subsystem, so reliability is improved as double writing without the need for software or DKC processing, and there is no problem with a magnetic disk failure during writing. The recovery function of double writing can be improved.

(Fourth Embodiment) FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

In the present embodiment shown in FIG. 4, in addition to the configuration of the first embodiment, the control circuit 210 has a magnetic disk 230 or 2
It is monitored whether or not the 40 has started the read operation, and further, the control circuit 210 and the read / write control circuit 2 for the interruption of the operation to the magnetic disk 230 or 240.
It has an operation suspending unit 4300 for instructing 80 or 290.

During the read operation of the first embodiment, the DKU
A case where the A230 reports the end of seek and orientation and starts the read operation will be described.
When the control circuit 210 receives a seek / orientation end report from the signal line 232 and instructs the read / write control circuit 280 to perform a read operation, the operation suspending unit 4300 causes the control circuit 210 and the read / write control circuit 2 to operate.
90 is instructed to stop all seek, orientation and read operations.

Since the DKU-B240 has not been accessed by the DKC100, suspending the operation has no effect, and the DK-B240 has no effect.
It is possible to wait for the next process from C100 early.

According to the present embodiment, the processing of the magnetic disk whose read operation has started later can be interrupted, so that it is possible to wait for the next processing (command) earlier.

Therefore, a series of processes for the subsystem can be speeded up.

(Fifth Embodiment) FIG. 5 is a block diagram showing a fifth embodiment of the present invention.

In the present embodiment shown in FIG. 5, in addition to the configuration of the first embodiment, the control circuit 210 is instructed to write data output from the magnetic disk control device 100 or read data output from the selector 270. Selector 5320 for selecting and outputting to write buffer 220
And a comparison circuit 5350 that compares the read data output from the selector 270 with the data output from the write buffer 220 and reports to the magnetic disk control device 100 whether or not they match. Reference numeral 5351 is a signal line output from the comparison circuit 5350.

During the read operation of the first embodiment, the DKU
The case of transferring the read data from the A230 to the DKC 100 will be described.

Since the control circuit 210 detects the seek / orientation end report from the signal line 232 first, the signal line 211 sends the selector 270 a DK signal.
The U-A 230 is instructed to select the read data, and the selector 5320 is instructed to select the read data output from the selector 270.

Further, the control circuit 210 gives a read / write control circuit 280 an instruction for a read operation and a signal line 213.
To the write buffer 22 to store the data output to the signal line 3321.

By these operations, the read data is transferred from the DKU-A 230 to the DKC 100 and the read data is stored in the write buffer 220.

Next, when the DKU-B 240 reports the end of seek and orientation, the control circuit 210 gives a read operation instruction to the read / write control circuit 290 and stores it in the write buffer 220 from the signal line 213. The output of the selected data to the signal line 221 and the selector 270 to select the read data from the DKU-B240.

The comparison circuit 5350 compares the data on the signal line 271 with the data on the signal line 221, and if the data do not match, an DKC10 error occurs.
Report to 0.

As described above, the data read first from a different disc is stored in the buffer, and the read data can be guaranteed by comparing it with the data of the disc read after the other disc.

Note that these functions can also be realized in the DKC 100.

According to this embodiment, since the data of two magnetic disks can be compared during the read operation, the function of ensuring the data during the read can be improved.

[0071]

As described above, according to the double-write magnetic disk subsystem of the present invention, the magnetic disk controller or software is a magnetic disk whose seek operation is always completed early without paying attention to double-writing. Only by accessing the magnetic disk controller, double writing can be performed at the time of writing, so the reliability of information as double writing is not impaired and the load on software and magnetic disk controller is not increased. Thus, the seek operation time can be further shortened, so that the processing of the magnetic disk subsystem can be improved within a fixed time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a fifth embodiment of the present invention.

[Explanation of symbols]

100 magnetic disk control device 101 signal line 102 write data signal line 200 magnetic disk device 210 control circuit 211 selector control signal line 212 signal line 213 signal line for instructing write buffer write data output 214 signal line for reporting the end of seek operation orientation 220 write buffer 221 write data output signal line 230, 240 magnetic disk 231 signal line for outputting read data 241 signal line for outputting read data 250, 260, 270 selector 251 signal line 261 signal line 271 signal line 280, 290 read / Write control circuit 281 Signal line for sending a command 291 Signal line for sending a command 2300 Status monitoring circuit 2310 Notification times 2311 notification signal line 3320,5320 selector 3321,5321 selector output signal line 3340 driver 3215 a signal line for outputting a signal line 4300 operating interruptions 5350 comparing circuit 5351 compares the results of the driver enable

Claims (1)

What is claimed is: 1. An information processing system comprising a magnetic disk control device and a magnetic disk device, wherein the magnetic disk device includes a first magnetic disk, a second magnetic disk, and a magnetic disk. The write buffer for storing the write data transferred from the disk control device, the write data transferred from the magnetic disk control device, or the write data stored in the write buffer is selected to select the write buffer. A first selector for outputting to one magnetic disk, and either the write data transferred from the magnetic disk control device or the write data stored in the write buffer, and selected to the second magnetic disk. Second selector for outputting, read data from the first magnetic disk, or the second magnetic disk A third selector for selecting any one of the read data from the above and transferring it to the magnetic disk controller, and receiving a command from the magnetic disk controller to seek to the first and second magnetic disks and the purpose Control of the selector and seek operation to the magnetic disk controller by judging which of the magnetic disk first has reported the end of the seek operation and the positioning operation to the target record. And a control circuit for reporting the end of the positioning operation to the target record and for instructing the output of the write data stored in the write buffer, and a read / write operation for the first magnetic disk according to the instruction from the control circuit. And a read / write control circuit for instructing read / write to the second magnetic disk according to an instruction from the control circuit. A dual-write magnetic disk subsystem having a read / write control circuit for instructing a write operation.