JPH01213710A - File controller - Google Patents

Abstract

PURPOSE:To improve the reliability of data protection by reading out data at the data transfer speed of the device side while storing data transferred from a host in a memory. CONSTITUTION:An online system consists of a host 1, a file controller 2 connected to the host in online, a magnetic disk device 3, and a magnetic tape device 4. The file controller 2 consists of an interface circuit 21 to the host 1, a command analyzing circuit 22, a magnetic disk control circuit 23, a magnetic tape control circuit 24, a memory 25, and an error detecting circuit 26. At the time of data write to the magnetic disk device 3, data is stored in the memory 25 by the control of the magnetic tape control circuit 24 and data is read out from the memory 25 at the data transfer speed of the magnetic tape device 4 and is written through the controller 24. Thus, data is written simultaneously though respective devices are different in data transfer speed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a file control device, and particularly to a file control device suitable for backing up file data using a plurality of external storage devices that are controlled differently. It is something.

[Conventional technology]

Conventionally, a system has been constructed by connecting a magnetic disk device to a host computer (hereinafter referred to as host) via a control device, and a magnetic tape device connected to the control device for data backup. It is known that the controller stores and reads data on a magnetic disk, and at the end of daily work, the control device automatically transfers the data in the magnetic disk device to a magnetic tape device to back up the data. (Refer to 1982-144270).

[Problem to be solved by the invention]

The conventional technology described above does not take into consideration data backup in the event of trouble during operation, and when an error occurs, it is necessary to request the host to resend the data again, resulting in the problem that recovery processing takes time. was there.

The purpose of the present invention is to solve such conventional problems, to simultaneously store data from a host in different external storage devices, to enable data backup during operation, and to perform recovery processing in the event of an error by requesting data retransmission. The object of the present invention is to provide a file control device that can perform file control without outputting data.

[Means to solve the problem]

In order to solve the above problems, a file control device of the present invention controls data transfer from a host device, controls data writing to a magnetic disk device or data reading to the host device, and controls a data backup device for data backup. A file control device that controls data writing and reading from a magnetic tape device includes a memory for absorbing the difference in data transfer speed between the magnetic disk device and the magnetic tape device, and a method for detecting data errors corresponding to these devices. An error detection circuit is provided, the data from the host device is stored in the magnetic disk device and at the same time stored in the memory, and the data stored in the memory is backed up at the transfer speed of the magnetic tape device, so that a data error occurs. In this case, the data is read from the device that normally stored the data and data recovery processing is performed.

[Effect]

In the present invention, the memory operates to store data transferred from the host device and read it at the data transfer speed of the device at the same time, so there is no malfunction such as data loss due to differences in data transfer speeds. . Further, since the error detection circuit operates in accordance with the device and also detects the location where an error occurs, erroneous data will not be stored during recovery processing.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a configuration diagram of an online system to which the present invention is applied.

In FIG. 2, 1 is a host, 2 is a file control device connected online to host 1, 3 is a magnetic disk device that stores and reads data under the control of file control device 2, and 4 is a magnetic tape for data backup. It is a device. In this embodiment, data backup is acquired during system operation under the control of the file control device 2, so recovery processing when an error occurs can be performed without issuing a data transfer request to the host 1. can.

FIG. 1 is a configuration diagram of a file control device showing an embodiment of the present invention. This shows a detailed configuration example of the file control device 2 in FIG. 2.

In FIG. 1, 21 is an interface circuit for interfacing with the host 1, 22 is a command analysis circuit for analyzing various commands, 23 is a magnetic disk control circuit for controlling the magnetic disk device 3, and 24 is a magnetic tape. A magnetic tape control circuit controls the device 24, 25 is a memory for absorbing differences in data transfer speeds, and 26 is an error detection circuit that detects errors depending on the device. below,
The operation of this embodiment will be explained.

When a data write command is issued from the host 1 to the magnetic disk device 3, it is analyzed by the command analysis circuit 22 via the interface circuit 21, and the data write is started in the magnetic disk control circuit 23 and the magnetic tape control circuit 24. By this activation, a data transfer request is made from the magnetic disk control circuit 23 to the host 1 via the interface circuit 21, and the data is transferred from the host 1 to the interface circuit 21.
Data is written to the magnetic disk device 3 via the magnetic disk control circuit 23. At this time, data is simultaneously stored in the memory 25 under the control of the magnetic tape control circuit 24, read out from the memory 25 at the data transfer speed of the magnetic tape device 4, and transferred to the magnetic tape device 4 via the magnetic tape control circuit 24. Write data to. This is because the data transfer speed sent from the host 1 is similar to that of the magnetic disk device 3, so it is faster than the data transfer speed of the magnetic tape device 4 and cannot be transferred as is. Therefore,
- Store data in the carrier memory 25, and transfer the memory 25 to the magnetic tape control circuit 24 at the data transfer speed of the magnetic tape device 4.
stores data in the magnetic tape device 4 under control. This allows data to be written at the same time even if there are differences in data transfer speed between devices.

Furthermore, when an error is detected by the error detection circuit 26 via the magnetic disk control circuit 23 during a read check after writing data to the magnetic disk device 3, the error detection circuit 26
instructs the command analysis circuit 22 to generate an error. Next, data stored in the magnetic tape device 4 is read from the command analysis circuit 22 to the magnetic tape control circuit 24 . At this time, since the error detection circuit 26 has detected the location of the error in the magnetic disk device 3, the command analysis circuit 22 analyzes the data write location of the magnetic tape device 4, reads out the same data, and stores it in the memory 25. do. When the data has been stored in the memory 25, the data in the memory 25 is read out from the magnetic disk control circuit 23, and the data is written to the location where the error occurred in the magnetic disk device 3 to perform recovery processing. As a result, the file control device 2 can transfer data without issuing a data transfer request to the host 1.
-Can perform evening recovery.

〔Effect of the invention〕

As described above, according to the present invention, data from a host can be stored simultaneously in two external storage devices with different transfer speeds, so data backup can be performed during operation. Since error recovery processing can be performed without going through the host, reliability of data protection is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a file control device showing an embodiment of the present invention, and FIG. 2 is a block diagram of an online system to which the present invention is applied. 1: host, 2: file control device, 3: magnetic disk device, 4: magnetic tape device, 21: interface circuit, 22: command analysis circuit, 23: magnetic disk control circuit, 24: magnetic tape control circuit, 25: memory , 26:
Error detection circuit. Figure 1

Claims (1)

[Claims] 1. A file that controls data transfer from a host device, controls writing data to a magnetic disk device or reading data to the host device, and controls data writing and reading from a magnetic tape device for data backup. The control device is provided with a memory for absorbing the difference in data transfer speed between the magnetic disk device and the magnetic tape device, and an error detection circuit for detecting data errors corresponding to these devices. is stored in the magnetic disk device and in the memory at the same time, the data stored in the memory is backed up at the transfer speed of the magnetic tape device, and if a data error occurs, the data can be retrieved from the device that normally stored the data. A file control device characterized by performing reading and data recovery processing.