JPH01248257A - Load distribution control system for input output to auxiliary storage device - Google Patents

Abstract

PURPOSE:To efficiently execute a load distribution processing by reporting dynamically a buffer use rate in an auxiliary storage controller to a central processor at the time of determining an input/output path to a device to which a data transfer is executed asynchronously. CONSTITUTION:The title system is provided with an input means 1 for fetching an input/output path which has executed an input/output operation to an auxiliary storage from an input/output path drawback table 2, an output means 3 for executing an input/output request to the auxiliary storage 7, and a discriminating means 5 which is provided on an auxiliary storage controller 6 and executes an execution propriety check by the input/output path which has been requested by a buffer use state of the auxiliary storage controller 6 and a load state decision processing of the auxiliary storage controller 6. Also, said system is provided with an input/output path redetermining means 8 for executing a selection of an alternative path at the time when the execution has been decided to be unsuitable, and an input/output path selection result storage means 9 for storing the input/output path which has executed an input/output request to the auxiliary storage device 7, in the drawback table 2. In such a way, a high speed transfer processing of data can be executed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an input/output load distribution control method for an auxiliary storage device of a computer system, and particularly to an auxiliary storage device having a buffer for high-speed data transfer processing. to the auxiliary storage device via the control device. This invention relates to a method for determining a route for making an input/output request.

[Conventional technology]

Conventionally, to determine the input/output path for an auxiliary storage device, for each auxiliary storage control device that is a higher-level device, the number of input/output requests to multiple auxiliary storage devices that are lower-level devices of the auxiliary storage control device is accumulated, and the value is calculated. The input/output path was set from the auxiliary storage controller that had the lowest value.

[Problem to be solved by the invention]

The conventional method for determining the input/output path for the auxiliary storage device described above is when input/output operations are performed synchronously between the auxiliary storage control device and the auxiliary storage device.

This was effective as a means of determining which auxiliary storage control device should be used for input/output. however,
If the auxiliary storage controller has a buffer to enable high-speed data transfer processing, and two individual buffers exist for each auxiliary storage controller, input/output operations will be performed between the auxiliary storage controller and the auxiliary storage controller. Because it is performed asynchronously between storage devices,
If the auxiliary storage control device to be used is determined based on the cumulative value of the auxiliary storage control devices used for input/output, there is a drawback that high-speed data transfer processing cannot be performed.

An object of the present invention is to eliminate the above-mentioned drawbacks and to distribute the load of input/output devices, which enables high-speed data transfer processing when input/output operations are performed asynchronously between the auxiliary storage control device and the auxiliary storage device. The objective is to provide a control method.

[Failure to solve the problem]

According to the present invention, to the auxiliary storage device via the auxiliary storage control device having a buffering function.

When performing input/output, an input means for extracting from a save table an input/output route that has performed an input/output operation to the auxiliary storage device immediately before the input/output operation, and an output means for making an input/output request to the auxiliary storage device; provided in the auxiliary storage control device,
A determining means for checking whether execution is possible on a requested input/output route based on buffer usage status of the auxiliary storage control device and load state judgment processing of the auxiliary storage control device, and an alternative route when execution is determined to be inappropriate. The present invention is characterized by comprising input/output route re-determining means for making a selection, and means for storing in the save table the input/output route that has made an input/output request to the auxiliary storage device. A load distribution control method for input/output to the auxiliary storage device is obtained.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the input/output load distribution control method for the auxiliary storage device according to an embodiment of the present invention is to control input/output to the auxiliary storage device 7 via the auxiliary storage control device 6 having a buffering function. When performing an operation, an input means 1 retrieves from the input/output route saving table 2 an input/output route that has performed an input/output operation to the auxiliary storage device 7 immediately before, and makes an input/output request to the auxiliary storage device 7. The output means 3 is provided in the auxiliary storage control device 6, and the output means 3 is provided in the auxiliary storage control device 6 to check whether or not the requested input/output route can be executed, and to determine the buffer usage status of the auxiliary storage control device 6 and the load state of the auxiliary storage control device 6. an input/output route re-determining unit 8 that selects an alternative route when execution is determined to be inappropriate; It is characterized by comprising an input/output route selection result storage means 9 which is stored in the save table 2.

Input means 1. Output means 3. Input/output route re-determination means 8. and input/output route selection result storage means 9, central processing unit 10
It is set in. The input/output route saving table 2 is provided in the main storage device 11.

In addition, in FIG. 1, 4 is a buffer control means.

Referring to FIG. 2, the auxiliary storage control device 6 (FIG. 1) consists of a pair of auxiliary storage control devices 12 and 13. The auxiliary storage control device 12 has a buffer 12a to enable a buffering function to speed up input/output operations, and controls reading and writing to the auxiliary storage device 7. The auxiliary storage control device 13 similarly controls the buffer 13
a, and controls reading and writing to the auxiliary storage device 7.

FIG. 3 is a flowchart showing an example of a process for determining an input/output path to the auxiliary storage device 7 under the auxiliary storage control device 12, 13 having a buffering function. Next, the operation of this embodiment will be explained with reference to FIG.

When determining the input/output path to the auxiliary storage device 7, the path on which the input/output operation was performed to the same device immediately before is fetched from the main storage device 11 (Sl).

An input/output request is made to the auxiliary storage device 7 using the fetched route (S2). An input/output request issued to the auxiliary storage device 7 is sent to the auxiliary storage device 7 via the auxiliary storage control device 12.
Served on.

The auxiliary storage control device 12 stores the auxiliary storage device 7 in the sofa 12a for the auxiliary storage device 7 for which input/output is requested.
Is there valid data remaining as unwritten data, or is there already /? A check is made to see if there is valid data that has been preloaded into the buffer 12a (S3). If there is valid data in the buffer 12a, the auxiliary storage control device 12 causes the auxiliary storage device 7 to perform an input/output operation according to the requested input/output path (SIO). Execution of input/output.

The process is completed by data transfer between the buffer area 111L in the main storage device 11 and the /J buffer 12a in the auxiliary storage control device 12.

When valid data does not exist in the buffer 12a of the auxiliary storage control device 12, valid data for the auxiliary storage device 7 exists in the buffer 13a of another auxiliary storage control device 13, which is a host device of the auxiliary storage device 7. A check is made as to whether or not (S4).

When valid data for the auxiliary storage device 7 exists in the buffer 13a of another auxiliary storage control device 13.

A request is made to the central processing unit 10 to set an alternative input/output route (S6).

When valid data regarding the auxiliary storage device 7 does not exist in the buffers in all the auxiliary storage control devices 12 and 13, which are higher-level devices, the auxiliary storage control device 12 prevents the use of the buffer by other subordinate auxiliary storage devices. It is determined whether or not it is in a high load state by considering the rate (S5).

When the central processing unit 10 determines that it is in a high load state, it requests the central processing unit 10 to set two alternative input/output paths (S
6).

When determining that it is not in a high load state, the auxiliary storage control device 12 requests the auxiliary storage device 7 to perform an input/output operation via the requested input/output path (S13).

In response to the request for setting an alternative input/output route, all routes leading to the auxiliary storage device 7 are checked to determine whether there are two alternative routes (S7).

When the auxiliary storage control device 13 that reaches the auxiliary storage device 7 exists, the input/output path is reset and re-execution is attempted (S2
).

In response to a request to set an alternative input/output route, all routes leading to the auxiliary storage device 7 are checked, and when there is no alternative route, an input/output request is forcibly made to the auxiliary storage device 7 (S9).
.

Note that under the 2 forced mode, the auxiliary storage control device 12 does not check the load state and causes the auxiliary storage device 7 to perform input/output operations (SIO).

When an input/output operation request is made to the auxiliary storage device 7, the set route is stored in the main storage device 11.

This stored path is used as a path when performing input/output operations to the secondary auxiliary storage device 7.

This process dynamically reports to the central processing unit the buffer usage rate (the load status of the auxiliary storage control unit) in the auxiliary storage control unit, which cannot be monitored from the conventional central processing unit, thereby improving load efficiency. Distributed processing is possible.

〔Effect of the invention〕

As explained above, the present invention is directed to an apparatus in which data transfer is performed asynchronously with a central processing unit, such as an auxiliary storage control apparatus having a auxiliary storage function. When determining input/output routes, the buffer usage rate in the auxiliary storage control unit (load status of the auxiliary storage control unit) is dynamically reported to the central processing unit, enabling efficient load distribution processing. .

Furthermore, by storing the immediately preceding input/output path on the main memory and reusing this path, the buffer can be used continuously, and efficient buffer use can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the functions of one embodiment of the present invention, FIG. 2 is a block diagram of the embodiment of the present invention, and FIG. 3 is a flowchart of processing according to the above embodiment. In fig. 1... Input means for obtaining input/output routes from the evacuation table;
2. A save table for input/output paths, 3. An output means for requesting an input/output operation to the auxiliary storage control device, 4.
・Buffer control means of the auxiliary storage control device (transfers data to and from the auxiliary storage device asynchronously with the central processing unit),
5... Discrimination means for checking the usage status of the buffer, etc. 6... Auxiliary storage control device. 7... Auxiliary storage device, 8... Input/output route re-determining means. 9... Input/output route selection result storage means, 10... Central processing unit, 11... Main storage device, 11a... Input/output buffer area in main storage device, 12... Auxiliary storage control Device, 12a...Buffer buffer in auxiliary storage control device 12, 13...Auxiliary storage control device, 13a...Buffer buffer in auxiliary storage control device 13.

Claims (1)

[Claims] 1. When performing an input/output operation to an auxiliary storage device via an auxiliary storage control device with a buffering function, a save table stores the input/output path that was used for the input/output operation to the auxiliary storage device immediately before. an input means for making an input/output request to the auxiliary storage device; and an output means for making an input/output request to the auxiliary storage device; A determination means for determining the buffer usage status and the load state of the auxiliary storage control device; an input/output route re-determination means for selecting an alternative route when execution is determined to be inappropriate; and for the auxiliary storage device. 1. A load distribution control method for input/output to an auxiliary storage device, comprising means for storing an input/output route that has made an input/output request in the save table.