JPH0738246B2 - Magnetic tape unit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape device, and more particularly, to failure handling of the magnetic tape device.

2. Description of the Related Art Conventionally, a magnetic tape device of this type has only detected a defect of a magnetic tape medium by reading it with a read head immediately after writing a block, and only reports the failure to a host device.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Since the above-described conventional magnetic tape device detects a defect of the magnetic tape medium during the data writing process of a certain block, a writing defect (wrong information is recorded or read) on the uneven portion. (Recording as impossible data) occurs, which causes a serious obstacle such as missing or loss of a data block when reading data.

The present invention has been made in view of the above-mentioned conventional circumstances,
Therefore, it is an object of the present invention to provide a novel magnetic tape device capable of solving the above-mentioned drawbacks inherent in the conventional technique.

Means for Solving the Problems In order to achieve the above object, a magnetic tape device according to the present invention has a control section for controlling the entire magnetic tape device and a capacity corresponding to one practical block, and one block's worth of capacity. Storage means for storing write data; unevenness detection means for detecting unevenness of the magnetic tape medium before a practical one block length; means for interrupting the writing process after the unevenness detection by the unevenness detection means; Means for creating a dummy block of a fixed length after interruption, means for automatically returning to the head of the block after creating the dummy block, and means for performing erasing processing beyond the distance from the head of the defective block to the unevenness And means for recording the stored data on a magnetic tape medium.

Embodiment Next, the present invention will be described in detail with reference to the drawings for a preferred embodiment thereof.

FIG. 1 is a block diagram showing an embodiment of the present invention.

Referring to FIG. 1, the magnetic tape device 1 includes a controller 2,
Dummy data storage unit 3, drive unit 4, write / erase control unit 5 for controlling write data 23 to the magnetic tape medium 9, unevenness detection unit 6 for the magnetic tape medium 9, and reading for reading data on the magnetic tape medium 9. It is composed of a head 7 and a writing head 8.

FIG. 2 is a diagram showing the relationship between the state of each block recorded on the magnetic surface of the magnetic tape medium 9 and the flaw 100 on the magnetic tape according to the present invention.

Next, the case of recording the block n-1 will be described.

When the control unit 2 receives a write command from a higher-level device (not shown) via the control line 10, the control unit 2 sends a forward travel instruction signal 15 to the drive unit 4, and after a certain time elapses, the write control line 11 is turned on. The write / erase control unit 5 is instructed to write the data via the data line 20, and the data of the block number n-1 sent from the host device is received via the data line 20 and sent out via the data line 21. At the same time, the data on the data line 20 is stored in the storage unit 19 via the data line 22.

When the writing of the data is completed, immediately after receiving the report via the control line 12, the control unit 2 sends an erasing signal 13 to write the creation of the gap c having a certain length in the magnetic tape medium 9. -Instruct the erase control unit 5. The writing / erasing control unit 5 that has received the erasing instruction creates the gap c via the write head 8 and the write data 23, and reports the end to the control unit 2 via the control line 12. Upon receiving the end report 12, the control unit 2 reports the end of the write command to the host device via the control line 10 and completes the write operation. During this period, the magnetic tape medium 9 is being sent at a constant speed.

Next, the operation relating to the present invention will be described with reference to FIG. 1 and FIG.

After the creation of the block n-1 and the gap c is completed as described above, the writing process of the next block n is started after the block n write command is received from the host device. Immediately after the start, at a distance a, the flaw 100 (unevenness) on the medium 9 is detected by the unevenness detecting unit 6. The distance a has a practical length of one block or more. That is, the unevenness detection unit 6 uses the write head 8
The magnetic tape medium is installed over a distance a and constantly monitors the state of the magnetic tape medium one block or more before. Unevenness detection unit 6
The control unit 2 receiving the detection signal 14 from the data line 20 stops transmitting the write data from the data line 20 via the data line 21, and simultaneously sends the dummy data from the dummy data storage unit 3 via the data line 24. And continues to send it to the read data line 21. As a result, the block n ′ is recorded on the magnetic tape medium 9.

The control unit 2 that has finished reading the dummy data creates the gap c ′ in the same manner as the above-described operation. Next, the control unit 2 instructs the drive unit 4 to issue the backward running instruction signal 16, and rewinds to the point α on the magnetic tape medium 9. The rewinding operation is performed as follows. The controller 2, which has continuously monitored the output 17 from the reading head 7, detects the dummy block and continues to detect the gap c, and clears the backward running instruction signal 16 to run the magnetic tape medium 9. Stop.

Next, in order to erase the magnetic tape medium 9 located at the distance b from the middle point α of the gap c, the control unit 2 controls the write / erase control unit 5
The erase signal 13 is continuously transmitted to the. After the erasing is completed, the control unit 2 sends a forward running instruction signal 15 to the drive unit 4, and after a certain time has elapsed, the write data of the block n is read from the storage unit 19 via the data line 22, and the data line 21 is read. By starting the data transfer to and writing to the write / erase control unit 5 via the control signal 11, the block n is correctly recorded.

Thereafter, the magnetic tape medium 9 is recorded in the same manner as when recording the block n-1.
The writing of the data 20 to is continued.

As described above, the defective writing due to the flaw 100 is prevented.

As described above, according to the present invention, a defect (unevenness) of a magnetic tape medium is detected before data writing, and a defective portion is erased, thereby preventing a data writing defect due to the uneven portion, It is possible to prevent data loss, improve system reliability, and effectively use resources.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
The figure shows the state of the magnetic tape medium. DESCRIPTION OF SYMBOLS 1 ... Magnetic tape device, 2 ... Control part, 3 ... Dummy data storage part, 4 ... Drive part, 5 ... Write / erase control part, 6 ... Unevenness detection part, 7 ... Read head, 8 ... Write head, 9 ... magnetic tape medium, 10, 11, 12, 13, 14, 15, 15, 16, 17 ... control signal, 19 ... storage section, 20, 21, 22, 23, 24 ... data line, 100 ... flaw on magnetic tape, n, n ′… block number, a, b, c, c ′… distance, α…
Midpoint of gap c

Claims (1)

[Claims] 1. A magnetic tape device, comprising: a control unit for controlling the entire magnetic tape device; and a write-only unit having a capacity corresponding to one practical block.
Storage means for storing write data for blocks, unevenness detection means for constantly detecting unevenness (defectiveness) on the surface of the magnetic tape medium before a practical one block length, and writing processing after unevenness detection by the unevenness detection means Means for interrupting, means for creating a dummy block of a certain length after the interrupting of the writing process, and head of a defective block automatically after the creation of the dummy block (head of a block including the dummy block in which processing is interrupted) ), Means for erasing a fixed length exceeding the distance from the head of the defective block to the unevenness, and means for recording the stored data on the magnetic tape medium after erasing by the erasing means. Magnetic tape device featuring.