JPH05224780A - Method for resetting input/output subsystem - Google Patents

Abstract

PURPOSE:To provide the subject method by which a system reset is executed by subsystem unit and a subsystem is reset by easily introducing even to a test program without affecting another input/output subsystem, in the input/ output subsystem, in which an input/output device of a magnetic disk device, etc., is controlled by an input/output controller. CONSTITUTION:In the input/output subsystem provided with an input/output device 4 to execute input/output operations and an input/output controller 3 to control the execution of an instruction by selecting the input/output device 4 corresponding to the instruction from a channel device 2 of a host device 1, a system reset command at a channel command level is prepared and, the input/output controller 3 executes system reset by the subsystem unit according to the system reset command.

Description

Detailed Description of the Invention

(Table of Contents) Industrial Application Field of the Prior Art (FIG. 5) Problem to be Solved by the Invention Means for Solving the Problem (FIG. 1) Action Example (a) Description of the First Example ( 2 to 3) (b) Description of the second embodiment (FIG. 4) (c) Description of another embodiment

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system reset method for performing system reset in subsystem units in an input / output subsystem in which an input / output controller controls an input / output device such as a magnetic disk device.

With the increase in data processed by computers (hosts), a large number of input / output subsystems such as magnetic disk subsystems are installed. In such a subsystem, a command from the host causes the I / O controller to
Select an I / O device and execute a command,
It is necessary to reset the subsystem when an error occurs or at the time of testing, and it is required to reset each subsystem.

[0004]

2. Description of the Related Art FIG. 5 is an explanatory diagram of a conventional technique. In the figure, 1 is a host device, which is composed of a computer, a workstation, etc., 2 is a channel device, which operates as a channel of the host device 1, 3 is an input / output control device, and magnetic disk control Configured by a device or the like, for connecting and controlling a plurality of input / output devices 4,
Reference numeral 4 denotes an input / output device, which is composed of a magnetic disk device or the like and operates for input / output.

The input / output subsystem is the input / output control unit 3.
In this example, two input / output subsystems are connected under one channel device 2.

In such a system, it is necessary to perform reset processing in error recovery processing when an abnormality occurs in one input / output subsystem, and it is also necessary to confirm whether reset is normally performed in device testing. There is.

Therefore, the conventional input / output subsystem has two
It had a kind of reset function. One is a CLEAR SUBCHANNEL command provided as an IO command (channel command), and this command is one I / O device 4 connected under the control of the I / O controller 3. This is a selective reset function that resets in units, but when the cause of the abnormality in the I / O subsystem is the I / O controller 3 itself,
Not effective.

[0008] The other is a reset channel pass (RESET CHANNEL PATH) instruction, which is a more powerful reset when an error occurs in the clear sub-channel instruction in the error recovery processing. However, since the reset is performed in units of channels, all the input / output subsystems connected to one channel are reset.

[0009]

However, the prior art has the following problems. To reset the I / O subsystem in the error recovery processing or test program, only the specified I / O device can be reset by the clear subchannel instruction, and the I / O controller and other I / O devices cannot be reset. ..

1 for the reset channel pass instruction
When multiple I / O subsystems are connected to one channel, all I / O subsystems are reset,
Error recovery processing resets other I / O subsystems that you do not need.

Further, in the reset channel path instruction, even if one input / output subsystem is connected to one channel, the reset channel path instruction is a command of an OS (operating system) level. Therefore, it cannot be incorporated into the test program.

Therefore, the present invention provides a system reset method for an input / output subsystem that can be easily installed in a test program without affecting other input / output subsystems to reset the input / output subsystem. The purpose is to provide.

[0013]

FIG. 1 shows the principle of the present invention. According to claim 1 of the present invention, an input / output device 4 for performing an input / output operation, and an input / output control device 3 for selecting the input / output device 4 in response to an instruction from the channel device 2 of the host device 1 and controlling execution of the instruction. In an input / output subsystem having and
A channel reset command system reset command is prepared, and the input / output control device 3 resets the system in subsystem units in response to the system reset command.

According to claim 2 of the present invention, in claim 1,
The input / output control device 3 is characterized in that, in response to the system reset command, it reports the normal end of the command to the host device 1 and then performs a system reset in subsystem units.

According to a third aspect of the present invention, in the first or second aspect, a plurality of the input / output control devices 3 are connected to the channel device 2 and the input / output control devices 3 are connected according to the system reset command. Is characterized by performing a system reset in subsystem units.

A fourth aspect of the present invention is the array type system according to the first or second aspect, wherein the input / output system is an array type system in which a plurality of the input / output devices 4 are connected in parallel to the input / output control device 3. It is characterized in that the input / output control device 3 performs a system reset in subsystem units in response to a reset command.

[0017]

According to the first aspect of the present invention, the system reset command at the channel command level is prepared as a command, and the I / O controller 3 responds to the system reset command by the subsystem unit system. Since the reset function is provided, the target subsystem can be reset even if a plurality of input / output subsystems are connected to one channel, and the present invention can be applied to a test program.

According to a second aspect of the present invention, the input / output control device 3
Responds to the system reset command by reporting the normal completion of the command to the higher-level device 1 and then performing a system reset in subsystem units, which can be realized without changing the normal IO command sequence with the higher-level device 1. ..

In the third aspect of the present invention, the input / output control device 3
A plurality of I / O subsystems are connected to the channel device 2, and the I / O control device 3 performs a system reset in subsystem units in response to the system reset command. Therefore, a plurality of I / O subsystems are connected to one channel. , You can reset the desired subsystem.

According to a fourth aspect of the present invention, the input / output system is an array type system in which a plurality of the input / output devices 4 are connected in parallel to the input / output control device 3, and the input / output system is input in response to the system reset command. Since the output control device 3 performs system reset in subsystem units, even if one I / O array subsystem is connected to one channel, issue a system reset command from the test program to reset the subsystem. You can

[0021]

【Example】

(a) Description of First Embodiment FIG. 2 is a configuration diagram of a first embodiment of the present invention, showing a magnetic disk subsystem.

In FIG. 2, the same components as those shown in FIG. 5 are designated by the same symbols, 6 is a channel interface control unit for performing interface control with the channel device 2, and 7 is a command. The lower magnetic disk device 4 which is a control unit in response to a command from the host 1.
And a data transfer control unit 8 which will be described later,
It has a processor (MPU) 70 for controlling the channel interface control unit 6, the data transfer control unit 8, and the lower interface control unit 9, a control table, a control storage 71 for storing control programs, and a register 72 for storing control data. It is a thing.

A data transfer control unit 8 controls data transfer between the lower magnetic disk device 4 and the channel 2, and a lower interface control unit 9 is connected to the lower magnetic disk device 4 and is magnetic. The interface control with the disk device 4 is performed.

In this figure, only one subsystem 3, 4 is connected to one channel 2, but in reality,
Two or more subsystems 3 and 4 are connected to one channel 2.

In this system, a pseudo system reset (PSUED) is newly added as a channel command.
O SYSTEM RESET) command is defined, and the function of system reset is added to the input / output control unit 3 by the microprogram in response to the command.

FIG. 3 is a process flow chart of the first embodiment of the present invention. The channel interface control unit 6 uses the channel device 2
Waits for a control command from
/ O or other.

If it is a start I / O, the channel interface control unit 6 receives the next channel command, and the processor 70, upon receiving this, determines whether this command is a pseudo system reset command.

When the processor 70 determines that the command is not the pseudo system reset command, it executes the command such as a read or write command. For example, in the case of a read command, the data transfer control unit 8 is set, a seek command to the target track is issued to the magnetic disk device 4 via the lower interface control unit 9, the seek operation is performed, and when the seek is completed, the magnetic disk device 4 Data is transferred from the data transfer control unit 8 to the channel device 2 from the channel interface control unit 6.

Then, the processor 70 reports the normal end of the command from the channel interface controller 6 to the channel device 2, and returns to the step. When the processor 70 determines that the command is the pseudo system reset command, first, the channel interface control unit 6 reports the normal end of the command to the channel device 2, and proceeds to the step.

In step, the processor 70
If the received control command is a reset channel pass command or system reset of the entire computer system, proceed to step.

The processor 70 sets the magnetic disk control device to the control unit busy state, and the magnetic disk control device 3 and all magnetic disk devices 4 connected under the magnetic disk control device 3 are
Perform a system reset.

In the system reset processing, the control table 71 in the magnetic disk control device 3 is initialized, the register 72 is initialized, the error is reset, and all the magnetic disk devices 4 under the magnetic disk control device 3 are connected. Performs processing such as error reset.

Then, the processor 70 releases the control unit busy state of the magnetic disk controller and returns to the step. In this way, start I /
Since a pseudo system reset command is provided for channel commands below the OS level such as O and reset channel pass commands, and the input / output control device 3 is designated by start I / O, the target input / output subsystem Only the system can be reset without affecting other I / O subsystems under the same channel.

It can also be issued from a test program to test the system reset process. (b) Description of Second Embodiment FIG. 4 is a block diagram of the second embodiment of the present invention, showing an array disk device.

In FIG. 4, the same components as those shown in FIG. 2 are designated by the same symbols. In the array disk device, the array disk control device 3 controls the upper interface control unit 5 and the magnetic disk devices 40 to 49 (data disks 40 to 47, parity disk 48, spare disk 49) and device control units 90 to 99. Have and.

The upper interface control unit 4 is a channel interface control unit 6 connected to the channel device 2.
And a command control unit 7 that is connected to the channel interface control unit 6 and controls each of the device control units 90 to 99.
And a data transfer control unit 8 that is connected to the channel interface control unit 6 and the command control unit 7 and that transfers data to each of the device control units 90 to 99.

Further, the device control units 90 to 99 transfer data for exchanging data between the command control units 900 to 990 for positioning and transfer control by the command of the command control unit 7 and the data transfer control unit 8. Buffers 901 to 991.

The magnetic disk device comprises eight data disks 40 to 47 and their parity (redundancy) disks 48.
And a block ID included in a logical block of 1 block 4096 bytes, which is composed of a spare disk 49 for failure, is normally driven in parallel by the magnetic disk devices 40 to 48, and is recognized by the host interface control unit 4, and Block ID of the block in the 512-byte physical magnetic disk device (drive) 40-48
Corresponds.

Also in such an array disk device, when the command control section 7 determines that the command is a pseudo system reset command, first, the channel device 2
, The channel interface controller 6 reports the normal end of the command, and executes the system reset,
Further, the system reset is executed in response to the reset channel pass command or the system reset of the entire computer system.

That is, the magnetic disk control device 3 is set in the control unit busy state, and the system reset is performed for the magnetic disk control device 3 and all magnetic disk devices 4 connected under the magnetic disk control device 3. To execute.

In the system reset process, the command control unit 7 in the magnetic disk control device 3 and the control tables in the command control units 900 to 990 in the device control units 90 to 99 are initialized, and the registers are initialized. Processing such as error reset and error reset of all the magnetic disk devices 40 to 49 connected under the magnetic disk control device 3 is executed.

Since one array disk device is connected to one channel device 2 in the array disk device, a system reset command can be issued and a system reset execution state can be tested by a test program.

(C) Description of Other Embodiments In addition to the above embodiments, the present invention can be modified as follows. Although the input / output device has been described as a magnetic disk device, it can be applied to other input / output devices.

Although the example of the magnetic disk device has been described, the present invention can be applied to a magneto-optical disk device, a magnetic tape device, a rewritable optical disk device, a semiconductor disk device and the like. Although the present invention has been described with reference to the embodiments, various modifications are possible within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

[0045]

As described above, according to the present invention,
It has the following effects. A system reset command is prepared as a channel command, and the I / O controller executes a system reset in response to this, so the target I / O subsystem is not affected without affecting other I / O subsystems under the channel. The system can be reset and error recovery processing can be diversified.

A system reset command can be issued from the test program, and the system reset operation can be verified by the test program.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a first embodiment of the present invention.

FIG. 3 is a processing flowchart of the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1 host device (upper device) 2 channel device 3 magnetic disk control device (input / output control device) 4 magnetic disk device (input / output device) 5 upper interface control unit 6 channel interface control unit 7 command control unit 8 data transfer control unit 9 Lower interface controller 90-99 Device controller

Claims (4)

[Claims] 1. An input / output device (4) for performing an input / output operation,
A channel command in an input / output subsystem having an input / output control device (3) for selecting the input / output device (4) and controlling execution of the command by an instruction from the channel device (2) of the host device (1) A system reset method for an input / output subsystem, characterized in that a level system reset command is prepared, and the input / output control device (3) resets the system in subsystem units according to the system reset command. 2. The input / output control device (3), in response to the system reset command, reports a normal end of the command to the host device (1) and then performs a system reset in subsystem units. The system reset method of the input / output subsystem according to claim 1. 3. A plurality of the input / output control devices (3) are connected to the channel device (2), and the input / output control devices (3) are system reset in subsystem units in response to the system reset command. The system reset method of the input / output subsystem according to claim 1, wherein 4. The input / output system is an array type system in which a plurality of the input / output devices (4) are connected in parallel to the input / output control device (3), and the input / output system is operated in response to the system reset command. 3. The system reset method for an input / output subsystem according to claim 1, wherein the controller (3) resets the system in subsystem units.