JPH0258707A - Magnetic tape device - Google Patents

Abstract

PURPOSE:To prevent occurrence of defective data writing and data omission caused by a recessed and projection part by providing a ruggedness detecting means, detecting and erasing a defecting part of a magnetic tape medium before writing data. CONSTITUTION:After receiving a block (n) writing instruction, a scratch (ruggedness) 100 on a medium 9 is detected by means of a ruggedness detecting section 6 at a distance (a). While a block (n') is recorded on the medium 9, a reverse running instructing signal 16 is outputted and the medium 9 is rewound until a point on the medium 9. Then the section of a distance (b) from the middle point alpha of a gap (c) of the medium 9 is erased. After the lapse of fixed time, the writing data of the block (n) are read out from a storing section 19 through a data line 22 and data transfer is started to a data line 21. At the same time, writing is instructed to a write/erase controlling section 5 by means of a control signal 11. As a result, the block (n) is properly recorded. Therefore, such a serious fault as omission or missing of a data block is not produced at the time of data reading.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetic tape devices, and more particularly to failure handling in magnetic tape devices.

2. Description of the Related Art Conventionally, this type of magnetic tape device only detects a defect in a magnetic tape medium by reading a certain block using a read head immediately after writing, and reports the defect to a host device.

Problems to be Solved by the Invention The conventional magnetic tape device described above detects a defect in the magnetic tape medium during the data writing process for a certain block. This has the drawback that the cheetah block may be recorded as impossible data), causing serious problems such as removal or loss of the cheetah block when reading data.

The present invention has been made in view of the above-mentioned conventional situation,
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel magnetic tape device which makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional technology.

Means for Solving the Problems In order to achieve the above object, a magnetic tape device according to the present invention includes a control unit that controls the entire magnetic tape device, a capacity corresponding to one practical block, and a storage capacity corresponding to one block. a storage means for storing write data; an unevenness detecting means for detecting unevenness on a magnetic tape medium before a practical one block length; means for interrupting a writing process after the unevenness detecting means detects the unevenness; means for creating a dummy block of a certain length after interruption; means for dynamically returning to the beginning of the block after creating the dummy block; and means for performing erasure processing beyond the distance from the beginning of the defective block to the unevenness. , and means for recording the storage data on a magnetic tape medium.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

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

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

FIG. 2 shows the state of each block recorded on the magnetic surface of the magnetic tape medium 9 according to the present invention and the flaws 100 on the same magnetic tape.
FIG.

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

When the control unit 2 receives a write command from the host unit W (not shown) via the control line 10, it sends a forward direction running instruction signal 15 to the drive unit 4, and after a certain period of time has elapsed, the control unit 2 outputs a write command via the control line 11. It instructs the write/erase control unit 5 to write via the data line 20, and receives the data of block number n-1 sent from the host device via the data line 20, and sends it out via the data line 21. At the same time, the data on data line 20 is transferred to data line 22.
The data is stored in the storage unit 19 via.

When the data writing is completed, immediately after receiving the report via the control line 12, the control unit 2 sends an erase signal 13,
The write/erase control unit 5 is instructed to create a gap C having a certain length in the magnetic tape medium 9. The write erase control unit 5 receives the erase instruction, and the write head 8 and the write data 23
A gap C is created via the control line 12, and a completion report is sent to the control unit 2 via the control line 12. Control unit 2 receives completion report 12
reports the completion of the write command to the host device via the control line 10, and completes the write operation. During this time, the magnetic tape medium 9 is being fed at a constant speed.

Next, the operation related to the present invention will be explained using FIG. 1 and FIG. 2.

After completing the creation of block n-1 and gap C as described above, writing processing for the next block n is started after receiving a block n write command from the host device. Immediately after the start, a scratch 100 (unevenness) on the medium 9 is detected by the unevenness detection section 6 at a distance a.

The distance Ma has a length longer than one practical block length.

That is, the unevenness detecting section 6 is installed at a distance a from the write head 8, and constantly monitors the state of the magnetic tape medium one or more blocks in front. Upon receiving the detection signal 14 from the unevenness detecting section 6, the control section 2 stops sending the write data from the data line 20 via the data line 21, and at the same time transfers the dummy data from the dummy data storage section 3 to data. It continues to be sent to read data line 21 via line 24. As a result, block n' is recorded on the magnetic tape medium 9.

After reading out this dummy data, the control section 2 creates a gap C' in the same manner as in the above-mentioned operation.6 Next, the control section 2 instructs the drive section 4 with a reverse direction running instruction signal 16, and generates a magnetic Rewinding is performed to point α on the tape medium 9. The rewinding operation is performed as follows. The control unit 2, which constantly monitors the output 17 from the reading head 7, detects the dummy block and then continuously detects the gap C, clears the reverse direction running instruction signal 6, and stops the magnetic tape medium 9 from running. stop.

Next, in order to erase the magnetic tape medium 9 within a distance from the midpoint α of the gap C, the controller 2 continues to send the erase signal 13 to the write/erase controller 5. After the erasure is completed, the control unit 2 sends a forward direction running instruction signal 15 to the drive unit 4, reads out the write data of block n from the storage unit 19 via the data line 22 after a certain period of time has passed, and reads the write data of block n from the storage unit 19 via the data line 22. ] At the same time as starting data transfer to the block rl, the write/erase controller 5 is instructed to write via the control signal 11, thereby correctly recording the block rl.

Thereafter, writing of the data 20 onto the magnetic tape medium 9 continues in the same manner as when recording block n-1.

As described above, writing failures caused by the failure 100 are prevented.

As described in detail, the present invention detects irregularities (unevenness) on a magnetic tape medium before writing data, and erases the defective parts to prevent data writing failures due to the irregularities. It also prevents data omissions, improves system reliability, and makes effective use of resources.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a diagram showing the state of a 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. Reading head, 8...
Write head, 9...magnetic tape medium, 10.11.1
2, 1.3, 141.5, 16.17... control signal,
19... Storage section, 20, 21, 2223° 24... Data line, ]00... Scratch on magnetic tape, nn'...
・Block number, a, b, c, c' ・・Distance, α・・
Gap C midpoint patent applicant: Nichiki Electric Co., Ltd. Representative: Patent attorney: Yutabe Kumagai

Claims (1)

[Scope of Claim] A magnetic tape device, comprising: a control unit that controls the entire magnetic tape device; a storage unit that has a capacity corresponding to one practical block and stores one block of write data exclusively for writing; unevenness detecting means for always detecting unevenness (defects) on the surface of a tape medium before the length of one practical block; means for interrupting the writing process after the unevenness detecting means detects the unevenness; means for creating a dummy block of the same length; means for automatically returning to the beginning of the bad block (the beginning of the block including the dummy block whose processing was interrupted) after creating the dummy block; and unevenness starting from the beginning of the bad block. 1. A magnetic tape device comprising: means for erasing a predetermined length that exceeds a distance from . . . , and means for recording the stored data on a magnetic tape medium after being erased by the erasing means.