JPH0954743A - Channel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a channel device which can transfer even the data of a large capacity without interrupting transfer processing. SOLUTION: This channel device transfers the transfer data stored in a transfer data storage means of each CPU to a shared disk via a shared disk controller. The channel device is provided with a transfer size information store means 3 which stores the transfer size information on the transfer data, a transfer data reader means 4 which reads the transfer data of a size decided by the information stored in the means 3 out of the transfer data storage means, and a transfer data output means 4 which outputs the transfer data read by the reader means 4 to the shared disk controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel device capable of transferring a large amount of data from a plurality of CPUs to a shared disk.

[0002]

2. Description of the Related Art In a large-scale complex computer system as shown in FIG. 3, when a large amount of data is transferred from the channels of the CPU 1 and the CPU 2 to the shared disks 1 to 4, the data transfer time is long, so the shared disk The bus connecting the controllers 1 to 4 and the shared disk control controller is occupied for a long time, which exceeds the timeout detection time of the shared disk control controller.

FIG. 4 is a diagram for explaining a case where the CPU 1 and the CPU 2 output eight access requests to the shared disk control controller almost at the same time. As shown in the figure, when the transfer size of the transfer request output to the disks 1 to 4 is large, the disk 4
The transfer request issued to is in a waiting state.

When the transfer request for the disks 1 to 3 is completed and the request for the disk 4 is to be processed, the timeout detection time of the shared disk control controller is exceeded. In such a case, the shared disk control controller determines that a failure has occurred, performs error processing, and suspends the data transfer processing.

[0005]

In order to solve such a problem, it is conceivable to lengthen the time-out detection time of the shared disk control controller, but if such a method is adopted, failure detection will be delayed. There was a problem.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a channel device capable of transferring data even if the data has a large capacity without interrupting the transfer process. .

[0007]

Therefore, first, in order to achieve the above-mentioned object, the invention according to claim 1 transfers the transfer data stored in the transfer data storage means of each CPU via the shared disk control controller. In a channel device for transferring to a shared disk, transfer size information storing means for storing transfer size information of transfer data, and transfer data of a size determined by the information stored in the transfer size information storing means, It is characterized by further comprising: transfer data reading means for reading from the storage means; and transfer data outputting means for outputting the transfer data read by the transfer data reading means to the shared disk control controller.

According to a second aspect of the present invention, in the channel device according to the first aspect, the transfer size information stored in the transfer size information storage means is based on a timeout detection time of the shared disk control controller. It is characterized by being decided.

According to the first and second aspects of the present invention, the transfer data reading means reads the transfer data of a size determined by the information stored in the transfer size information storage means from the transfer data storage means and transfers the transfer data. Since the transfer data read by the transfer data reading means is output to the shared disk control controller by the data output means, a large amount of data can be transferred without interrupting the transfer processing.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The channel device of this embodiment is
By dividing a large amount of transfer data finely, transfer is performed to another disk without changing the timeout detection time.

However, if the divided transfer size of the transfer data is made smaller than necessary, this time, when it is used by one CPU, the transfer performance at the time of transferring a large amount of transfer data deteriorates. I will end up. In such a case, the transfer size of the transfer data should be as large as possible.

Therefore, the channel device of this embodiment is
By providing the channel with the function of selecting the division size of the transfer data, the division transfer size according to each system is determined and the transfer processing is performed.

FIG. 1 is a diagram showing the configuration of a channel device according to an embodiment of the present invention. As shown in the figure, C
Disks A to D are connected to PUA and CPUB via a common disk control controller 1.

The CPU A and the CPU B can output one access request to each of the disks A to D. Disk control controller 1
Can simultaneously receive access requests for eight (2 CPU × 4 drives). The timeout detection time until the disk access is completed by the disk control controller 1 is 3 seconds. This timeout detection time cannot be made longer than this in order to shorten the failure detection time.

Further, there is only one interface bus between the internal bus of the disk control controller 1 and the disks A to D. Therefore, while the transfer data is being transferred from the disk control controller 1 to one disk, the other disks are in a waiting state.

The switching control circuit 1a of the shared disk control controller 1 switches the channel of the CPU 1 and the channel of the CPU 2 at a predetermined timing and outputs the transfer data to any of the disks A to D.

The CPU A and the CPU B respectively include a non-volatile memory 2, a main memory 3 and a channel 4. The non-volatile memory 2 stores transfer size information of transfer data to be divided. Here, the transfer size of the transfer data is determined by the timeout detection time of the disk control controller 1 and the transfer speed.

In this case, the nonvolatile memory 2 has a maximum of 8
Even if all the transfer requests are large transfer data, a size that does not cause an error, for example, CPUA and CP
Information is stored that the transfer rate between the UB and each disk is 256 kilobytes, assuming 1 megabyte / second.

With such a transfer size, the connection bus to the inside of the controller and the disk can be released in a little over 2 seconds, and the transfer processing is not interrupted when the time-out detection time is exceeded.

In a system shared by a larger number of CPUs, if the divided transfer size is appropriately reduced, the maximum performance can be achieved without a timeout error in normal operation.

The main memory 3 stores transfer data. The channel 4 reads the transfer data of a size determined by the transfer size information of the transfer data written in the non-volatile memory 2, that is, the divided transfer data from the main memory 3 and outputs it to the shared disk control controller 1. To do.

Next, the operation of the channel device configured as described above will be described. When there is a transfer request from the CPU A to the disk A, the channel 4 reads the transfer data of the size determined by the transfer size information stored in the non-volatile memory 2 from the main memory 3 of the CPU A.

Then, as shown in FIG. 2, the channel 4 of the CPUA outputs the divided transfer data to the switching control circuit 1a of the disk control controller 1, and the switching control circuit 1a outputs from the channel 4 of the CPUA. The divided transfer data is output to the transfer destination disk (here, disk A).

Next, the switching control circuit 1a switches to the channel of the CPUB and outputs the transfer data to the transfer destination disk (here, the disk B) when the transfer data is output from the CPUB.

Thereafter, as shown in FIG. 2, the switching control circuit 1
a repeats the same operation and outputs the transfer data to the shared disk. Therefore, according to the channel device of the present embodiment, an optimum disk system can be constructed in terms of performance and reliability by providing a channel for connecting a shared disk with a function capable of selecting a divided transfer size.

[0026]

As described above in detail, according to the present invention,
Even for a large amount of data, the data can be transferred without stopping the transfer process.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a channel device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the channel device according to the same embodiment.

FIG. 3 is a diagram showing a configuration of a conventional channel device.

FIG. 4 is a diagram for explaining the operation of the conventional channel device.

[Explanation of symbols]

1 ... Shared disk control controller, 1a ... Switching control circuit, 2 ... Non-volatile memory, 3 ... Main memory, 4 ... Channel.

Claims (2)

[Claims] 1. A channel size device for transferring transfer data stored in a transfer data storage means of each CPU to a shared disk via a shared disk control controller. Transfer size information storage for storing transfer size information of transfer data. Means, transfer data reading means for reading transfer data of a size determined by the information stored in the transfer size information storage means from the transfer data storage means, and transfer data read by the transfer data reading means And a transfer data output means for outputting the data to the shared disk control controller. 2. The channel device according to claim 1, wherein the transfer size information stored in the transfer size information storage means is determined based on a timeout detection time of the shared disk control controller.