JPS5916066A - Data transfer system - Google Patents

Abstract

PURPOSE:To transfer recording data efficiently, by providing a block buffer which has capacity containing at least two data blocks between a magnetic disk device and a magnetic tape device, and transferring the data, block by block. CONSTITUTION:The block buffer 1 having capacity containing at least two data blocks is provided between the magnetic disk device 4 and a magnetic tape device 6. Then, a data block with the discrimination number of a track of the device 4 is transferred to the device 6 through an area A of the buffer 1 at block intervals (k) and data blocks on the track of the device 4 are transferred to the device 6 through an area B of the buffer 1 at intervals (k). In this case, the transfer is carried out alternately from the areas A and B and data blocks while shifted are repeated by k/2 times to transfer all pieces of information on the track to the device 6. Similarly, data are also transferred from the device 6 to the device 4.

Description

Detailed Description of the Invention (Technical Field) The present invention reduces the time required to copy and store data recorded in a magnetic disk device onto a magnetic tape, or to restore data recorded on a magnetic tape to a magnetic disk device. It is related to.

(Background technology) Conventionally, data recorded in magnetic disk devices was recorded and stored on magnetic tapes via the computer's main memory, but since the recorded data has a large capacity, due to the capacity limitations of the main memory, magnetic disks It was difficult to operate the device and the magnetic tape device continuously. Therefore, the operation of the magnetic disk device and the magnetic tape device had to be temporarily stopped for many times, resulting in wasted time. Further, it is necessary to issue startup commands to the magnetic disk device and the magnetic tape device many times depending on the main storage capacity using computer software, resulting in a problem of processing time.

(Problem to be solved by the invention) In order to eliminate these wasted times, the present invention efficiently records data in a magnetic disk device without stopping the operation of the magnetic tape device and without intermediating the main storage device of the computer. The purpose is to provide a method for recording data on magnetic tape and, conversely, a method for restoring data recorded in a magnetic tape device to a magnetic disk device. In the transfer method, a small block buffer with a capacity of 2 data blocks is provided between both devices, and data blocks with track identification numbers on the disk are transferred at predetermined block intervals (each IO to the first data block buffer). At the same time, another data block on the track is transferred to the magnetic tape via a second data block buffer at each block interval (lO), and the first and second data block buffers are transferred to the magnetic tape via a second data block buffer. The transfer from the buffer is performed alternately, and the same operation is repeated seven times while shifting data blocks to transfer all the information on the tracks on the disk to the magnetic tape. For a data transfer method such as transferring onto a disk (Structure and operation of the invention) FIG. 1 shows a first embodiment of the present invention, in which 1 is a block buffer, 2 is a block buffer control unit, and 3 is a magnetic disk control unit. 4 is a magnetic disk; 5 is a magnetic tape controller; 6 is a magnetic tape; 7 is a magnetic disk data bus;
8 is a magnetic disk block buffer control line, 9 is a magnetic tape data bus, and 10 is a magnetic tape block buffer control line.The operation according to this system is as follows.

When writing from a magnetic disk to a magnetic tape,
The trunk data on the magnetic disk is divided into blocks as shown in Figure 3 (A) and an identification number is assigned to each block.The identification number is the disk cylinder number, head number,
It has a sector number, and has, for example, 4 bytes. Figure 3 (
B) is the trunk rewritten in chronological order. Fourth
The figure shows the operation in chronological order. First, the block 1 with an identification number is read from the magnetic disk 4 by the control unit 3, and stored in A of the block buffer l (the block buffer is divided into one block 1 (, and the AM buffer is logically divided into A and A respectively).

In addition, when the data block on the magnetic disk 4 reaches block 5, block 5 is read in the same way as reading block 1, and block buffer 1 is named po.
Store in 0B. To write to the magnetic tape, when the completion of reading block 1 is notified to the control unit 2 via the control line 8,
The process starts when the control unit 2 instructs the control unit 5 to write via the control line 10, the control unit 5 reads data from the block buffer 1, and the control unit 5 writes data onto the magnetic tape 6.

After writing of A in block buffer 1 is completed, writing of 13 in block buffer l is performed in the same manner. When the data block on the magnetic disk 4 reaches block 9 during the write operation of B of block buffer l, it is similarly stored in block 8 of data block buffer l, which has already been written. In this way, the blocks of the magnetic disk 4 are read intermittently and stored alternately in the two buffers A and T3 of the block buffer l, and the blocks A and B of the block buffer 1 are
By sequentially writing the contents of
The magnetic tape never stops working. In this example,
Four revolutions of the disk copy the contents of one track onto the tape.

On the other hand, the fifth @ time series shows the case where data is written from a magnetic tape to a magnetic disk. First, magnetic tape 6
The control unit 5 reads out the block with the identification number l from
Store in A of block buffer 1. Then identification number 5
Similarly, the block of
Store in. One write to the magnetic disk is block 1.
Controls the end of reading #i! ] 0, the control unit 2 starts by instructing the control unit 3 to write through the control line 8, the control unit 3 reads the data from the block buffer 1, and the control unit 3 writes the block No.
1. Write to the position on the magnetic disk corresponding to 9. After writing of A to block buffer 1 is completed, writing to block buffer 10B is performed in the same manner. Further, data of block 9, which is the next block on the magnetic tape, is similarly stored in the block buffer IQ)A where writing has been completed. In this way, data blocks on the magnetic tape are read out sequentially, stored alternately in two buffers A and H of block buffer 1, and data blocks A and H of block buffer 1 are stored alternately.
By alternately writing the contents of 13 to the corresponding block positions on the magnetic disk, the magnetic tape operation does not stop.

In the example shown in Fig. 4, the contents of one track can be written to the magnetic tape in four rotations of the magnetic disk, and in the example shown in Fig. 5, the data on the magnetic tape can be written in one track in four rotations of the magnetic disk. Can be written to the cylinder.

Figure 2 shows an example of the internal structure of a block buffer, with 1
1 and 16 are driver receivers, 12 is RAM memory IJ-
113 is a switching gate, 14 is an address counter A, 1
5 is an address counter B.

The data on the magnetic disk 4 is transferred to the data busk, data bus 1.
1 and stored in I%AM]2. H, A at that time
The M address is already set in the address counter A14 by the control unit 2 for data block A, and the address of the address counter A14 is set to a by the switching gate 13.
It is shown in AM12. Data in l byte units R, A,
Each time the data is stored in M, the address counter 14 counts. When data is stored in data block B, address counter B similarly operates.

A similar process occurs when storing data from magnetic tape. Further, reading from the RAM is also the same except that the direction of data is different.

(Effects of the Invention) As explained above, in the first embodiment, the contents on the magnetic disk can be written without stopping the magnetic tape, or the contents of the magnetic tape can be written on the magnetic disk. There is an advantage that data can be replicated within the device running time.

In the embodiment shown in FIG. 1, the RAM is logically divided into A and 13 blocks as a block buffer, but the RAM is divided into n pieces or shifted according to the speed of the magnetic disk and magnetic tape. A similar effect occurs with registers.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing an example of a block buffer, Fig. 3 is an expanded view of information on a magnetic disk, and Figs. 4 and 5. FIG. 2 is an explanatory diagram showing that information is exchanged between a magnetic disk and a magnetic tape. 1...Meeting...Block Buffer 2...Br1 Block Buffer Control Unit Patent Applicant Oki Electric Industry Co., Ltd. Patent Application Agent Patent Attorney Megumi Yamamoto -

Claims (1)

[Claims] In a data transfer method between a magnetic disk device and a magnetic tape device, a block node with a capacity of at least two data blocks is provided between the two devices, and data blocks having trunk identification numbers on the disk are distributed at predetermined block intervals. (transfers every 10 data blocks to the magnetic tape via a first data block buffer, and transfers another data block on the track to the magnetic tape via a second data block buffer every 10 blocks). transfer, alternately transfer from the first and second data block buffers, and repeat the same operation seven times without shifting the data blocks to transfer all information on the tracks on the disk to the magnetic tape; A data transfer method characterized by transferring data on a magnetic tape to a magnetic disk using a similar operation;