JPS6224825B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reading and writing data in a duplex data storage device when accessing the data storage device without being aware that the data storage device is duplexed.

Conventional devices of this type have adopted a processing system having a configuration as shown in FIG. The processing method shown in FIG. 1 will be explained in detail below. 1 is a data transfer control device, 2 is a primary storage device, 3 is a duplication device data transfer request queuing device, 4 is a central data storage control device, 5A, 5B are data storage control devices, 6A, 6
B is a data storage storage device, and 7 is a duplex data storage device.

The data transfer control device 1 includes primary storage devices 2 and 2.
When a data transfer request with the duplex data storage device 7 is detected, the duplex device data transfer request queuing device 3
Submit a transfer request to. Central data storage control device 4
periodically reads the contents of the duplexing device data transfer request queuing device 3, and if there is a data transfer request, the data storage control devices 5A and 5
Send a transfer request to B.

If the request type is a data double write request, the central data storage controller 4 sends a write request to the data storage controllers 5A and 5B in order to write the data in the primary storage device 2 to the data storage devices 6A and 6B. After the transfer of data from the primary storage device 2 to the data storage devices 6A and 6B is completed, the central data storage control device 4 notifies the data transfer control device 1 of the completion of the transfer.

On the other hand, if the request type is a data read request, data is transferred from the data storage device 6A to the primary storage device 2.
In order to read the data, the central data storage control device 4 issues a read request to the data storage control device 5A, and after the data transfer is completed, notifies the data transfer control device 1 of the completion of the transfer.

By adopting such a processing procedure, the data transfer control device 1 does not need to be aware of duplication processing, but in the duplication data storage device 7, the processing of the data storage control device 5B becomes idle in the case of reading. In addition, in the case of writing to both devices, even if the processing of one device ends earlier, that device remains idle until the processing of the other device ends. Therefore, there is a drawback that the processing capacity of the duplex data storage device 7 is kept low.

In order to solve this drawback, the present invention aims to provide a system in which each device in a duplex data storage device can individually process read/write requests when the device becomes free for processing. . below,
The drawings will be explained in detail.

FIG. 2 is a block diagram showing one embodiment of the present invention, in which 1 is a data transfer control device, 2 is a primary storage device, 3 is a duplication device data transfer request queuing device, and 5A and 5B are data storage devices. Control device, 6A, 6
B is a data storage storage device, 7 is a duplex data storage device, 8A and 8B are data transfer request queuing devices compatible with the data storage control device, and 9 is a data transfer bus.

The operation of FIG. 2 is performed as follows.

The data transfer control device 1 includes primary storage devices 2 and 2.
When a data transfer request with the duplex data storage device 7 is detected, the duplex device data transfer request queuing device 3
Submit a transfer request to. The data storage control devices 5A and 5B periodically read the contents of the data storage control device compatible data transfer request queuing device 8A or 8B belonging to themselves, and if there is a data transfer request, perform data transfer processing according to the request type. Let's do it.

When the request type is a write request, the data storage control devices 5A and 5B write the data storage device 2 to the data storage device 6A or 6B that belongs to it.
data is transferred via the data transfer bus 9.
Here, as will be described later, the write request in the data storage control device compatible data transfer request queuing device 8A or 8B is the second double write transfer request. Therefore, the data storage control device 5A,
5B notifies the data transfer control device 1 of the completion of writing after the transfer process is completed.

On the other hand, if the request type is a read request, data is transferred from the data storage device 6A or 6B belonging to itself to the primary storage device 2 via the data transfer bus 9. Here, as will be described later, the read request in the data storage control device compatible data transfer request queuing device 8A or 8B is one for which the transfer process failed the first time in the other data storage control device 5A or 5B. Therefore, after the transfer process is completed, the data storage control devices 5A and 5B notify the data transfer control device 1 of the completion of reading.

Next, the data accumulation control devices 5A and 5B,
When the contents of the data transfer request queuing device 8A or 8B corresponding to the data storage control device belonging to the own device are periodically read, if there is no data transfer request, the contents of the duplexing device data transfer request queuing device 3 are read. , if there is a data transfer request, data transfer processing is performed according to the request type.

If the request type is a write request, the data storage control devices 5A, 5B transfer the data in the primary storage device 2 to the data storage device 6A or 6B belonging to themselves, respectively, via the data transfer bus 9. Since this transfer request is the first double-write transfer request, after the transfer process is completed, the data transfer request queuing device 8A corresponding to the other data storage control device
Alternatively, a second write request is made to 8B.

Further, when the request type is a read request, the data storage control devices 5A, 5B transfer the data from the data storage device 6A or 6B belonging to themselves to the primary storage device 2 via the data transfer bus 9. If this transfer process is normal, the data transfer control device 1 is notified of the end of reading. If this transfer process is abnormal, a second data transfer request queuing device 8A or 8B corresponding to the other data storage control device is sent to request the other data storage control device 5A or 5B to perform the transfer process again.
Make the second read request.

As explained above, according to the present invention, each duplexed data storage control device can perform transfer processing independently and in parallel, so there is an advantage that the processing capacity of the duplexed data storage device can be improved. .

[Brief explanation of the drawing]

FIG. 1 shows an example of the configuration of a conventional duplex data storage device. FIG. 2 shows an embodiment of a duplex data storage device according to the present invention. In the figure, 1 is a data transfer control device, 2 is a primary storage device, 3 is a duplication device data transfer request queuing device, 4 is a central data storage control device, 5A, 5B are data storage control devices, 6A, 6B are data Storage storage device, 7 is a duplex data storage device, 8A, 8B
9 represents a data transfer request queuing device corresponding to a data storage control device, and 9 represents a data transfer bus.

Claims (1)

[Claims] 1. In a duplicated data storage device, a first means for queuing a processing request for each data storage device, and a first means for queuing a processing request for a pair of duplicated data storage devices. each data storage device first processes the processing request that is waiting for each data storage device, and if there is no such request, the processing request is processed for the duplicated pair of data storage devices. 1. A read/write method for a duplex data storage device, comprising a third means for processing a processing request that is waiting for a data storage device.