JPS6047268A - Block managing method - Google Patents

Abstract

PURPOSE:To attain high reliability of recording/reproducing information by detecting a skipping of read of a data block due to various causes and skipping of read of a file due to skipping of a tape mark in early stage by means of the hardware. CONSTITUTION:Data block managing information comprising a tape mark identification number and a data block identification number is added and recorded on a recording medium comprising data blocks in the unit of management. In reading data, a read data is demodulated by a demodulation/read circuit 11, and an SMS circuit 12 stores temporarily the data block identification number (BSN1, BSN2 or the like) and the tape mark identification number (TSN1, TSN2 or the like) in the inputted data. An MPU15 compares the stored data block identification number and the tape mark identification number with an expected value of each number stored in the MPU15, a reading head is positioned correctly in the magnetic tape medium 1, the presence or absence of the skipping of read is judged and when the head is not at the correct position, it is indicated to a magnetic tape device 6 and the head is restored to the correct position.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical field of the invention The present invention provides a system for recording media that uses data blocks, which are physical recording processing units, as management units, from tape mark identification numbers and data block identification numbers. The present invention relates to a block management method for additionally recording data block management information.

(b) Background of the technology In conventional general magnetic tape devices, there was no concept of data block identification numbers in the block management method, so if magnetic tape devices are not properly maintained, magnetic tape Even if a positional shift occurs between the magnetic head and the normal recording/playback position of the data block, which is the physical recording processing unit on the magnetic tape, due to bending or excessive slipping, it cannot be checked by the hardware, and it cannot be checked by the software. It could not be detected without checking.

There is a need for an efficient method that automatically detects data block omissions due to the above causes at an early stage using hardware, processes them appropriately, and ensures reliability of recorded/reproduced information.

(c.) Prior and advanced technologies and problems The conventional block management method is explained using a magnetic tape device as an example.
This will be explained with reference to the drawings.

FIG. 1 shows an example of a data block on a conventional magnetic tape.

In the figure, 1 indicates a magnetic tape medium, 2 indicates a data block (a), and 3 indicates a tape mark.

Conventional data block (a) 2 does not have an identification number attached to it, so when reading data block (a) 2, it is difficult to detect folds in magnetic tape medium 1 or the capstan (not shown) that runs magnetic tape medium 1. ) Data block (a) 2 is misaligned with the magnetic head (not shown) due to excessive slip due to a defect, etc.
Even if a read failure occurs in data block (a) 2
There are cases where reading is terminated without being able to detect a reading omission, and it cannot be determined without checking the data with software.

There is also a forward space command that advances the magnetic tape in the forward direction (the forward running direction of the magnetic tape medium 1) and stops when tape mark 3 is detected, and a tape mark command that advances the magnetic tape in the backward direction (the reverse running direction of the magnetic tape medium 1). Even when executing the hackword space command, which stops when 3 is detected, even if tape mark 3 is skipped and swiped at the primary tape mark 3, there is a problem in that the missing data file cannot be detected at that point. there were.

(d) Purpose of the Invention The object of the present invention is to provide a new block management method that eliminates the above-mentioned drawbacks. By automatically adding 11 to the location.

The object of the present invention is to realize a block management method that ensures high reliability of recorded/reproduced information.

(6) Structure of the Invention The present invention provides a recording medium in which a data block, which is a physical recording processing unit, is a management unit, and a data file is constituted by a predetermined number of data blocks, when information is recorded on the recording medium. , recording a tape mark identification number for each tape mark recorded to divide the data block into data file units, and recording a data block identification number for each data block between the tape marks; By detecting skipping of the data block or data file using the identification information when reading information on the recording medium.

This can be achieved by a block management method characterized by ensuring high reliability of recorded/reproduced information.

(f) Examples of the invention The present invention will be explained below with reference to the drawings.

FIG. 2 shows a magnetic tape block management method according to an embodiment of the present invention, FIG. 3 shows a magnetic tape control device according to an embodiment of the present invention, and FIG. 4 shows a magnetic tape medium according to an embodiment of the present invention. Examples of data formats are shown below.

In the figure, 4 is a data block (b), 5 is a magnetic tape control device, 6 is a magnetic tape device, 7 is an interface circuit, and 8 is a multiplexer circuit.

9 is a buffer circuit, 10 is a modulation/write circuit, 11 is a demodulation/read circuit, 12 is a serial number generation circuit (hereinafter abbreviated as SNS circuit), and 13 is a serial number generation circuit (hereinafter abbreviated as SN generation circuit). , 14 is a comparison circuit, 15 is a microprocessor (hereinafter abbreviated as MPII), 16 is an A zone data group, 17 is a B zone data group, 18 is a data group (i), 1
9 indicates a data group (ii'), and 20 indicates a residual data group.

Furthermore, the data block identification number (BNI, BN2.,...)
, tape mark identification number (TNI, TN2., ,),
Data block identification number check flag (described later)
etc. are collectively referred to as data block management information.

This embodiment of the magnetic tape control device is a magnetic tape control device 5. which converts commands and data from a host device (not shown) into a form that passes through a magnetic tape device 6, transmits it, and controls it.
A magnetic tape device 6 that records/reproduces pain data on the magnetic tape medium 1 according to instructions from the magnetic tape control device 5. Interface circuit 7 for exchanging information with a host device (not shown). Interface circuit 7. f summer tone/lead circuit 11. A multiplexer circuit 8 that selects the manual data from the SN generation circuit 13 and outputs it to the buffer circuit 9. A buffer circuit 9 that temporarily stores the manual data from the multiplex signal circuit 8 and sequentially outputs it to the modulation/write circuit 10. Modulation/write circuit 10° that modulates input data from the buffer circuit 9 and transfers it as write data to the magnetic tape device i6; Demodulation/read circuit 11° that converts read data from the magnetic tape device 6 into demodulated read data. SNS circuit 1 that extracts data block management information from read data input from demodulation/read circuit 11
2. SN generation circuit 13 that creates data block management information according to instructions from liver 015. A comparator circuit 14 that compares the data input from the SNS circuit 12 with the data manually input from the SN generation circuit 13 and outputs the result to the MPU 15. S
It consists of the MPU 15 which instructs the N generation circuit 13 and determines whether correct data is written in the correct position based on input data from the two comparator circuit 14.

The operation of this embodiment will be explained below with reference to FIGS. 2 and 3.

Write data transferred from a host device (not shown) is sent to the interface circuit 7. The signal is stored in a buffer circuit 9 via a multiplexer circuit 8. When the transfer from the host device (not shown) is completed, the multiplexer circuit 8 switches to the SN generation circuit 13 side, and the buffer circuit 9 receives the data block identification number (
BSN 1 , B5N2, etc.) and tape mark identification numbers (TSN 1 , TSN2, etc.) are transferred and stored in the same way.

Next, the data stored in the buffer circuit 9 is sequentially read out, transferred to the magnetic tape device 6 through the modulation/write circuit 10, and written onto the magnetic tape medium 1.

To check whether the data written on the magnetic tape medium 1 by the write head (not shown) of the magnetic tape device 6 has been written correctly.

immediately read by a reading head (not shown);
It is output to the SNS circuit 12 via the demodulation/read circuit 11.

In the 5NSl path 12, data block identification numbers (BSN 1, BSN 2
etc.) and tape mark identification numbers (TSN l, TSN
2 etc.) and temporarily throw it away. Next, comparator circuit 1
4 compares the data stored in the SNS circuit 12 and the data generated by the SN generation circuit 13 and sends the result to MP[11
Notify 5.

Next, when data is read from the magnetic tape medium 1, the read data is transferred to the fjE tone/read circuit 11, similar to the read operation for checking during writing. The demodulation/read circuit 11 demodulates the transferred read data and sends it to the multiplexer circuit 8 and the SNS circuit 1.
Output to 2. In the SNS circuit 12, the data block identification number (BSN 1, BS
N2, etc.) and tape mark identification numbers (TSN '1,
T'SN 2 etc.) can be temporarily dropped.

The MPU 15 reads the data block identification numbers ('BSN 1, BSN 2, etc.) stored in the SNS circuit 12,
Compare the tape mark identification numbers (TSN 1, TSN'2, etc.) with the expected values of each number stored in the MPU 15 to ensure that the reading head (not shown) is correctly positioned on the magnetic tape medium 1. Check if there was any skipping, etc., and if it is normal, proceed to the next operation. If it is thrown at the correct position, the MPU 15 determines that it instructs the magnetic tape device 6 to position it at the correct position via a circuit not shown in the figure, and returns it to the correct position.

Next, the data block format recorded on the actual magnetic tape medium 1 will be explained with reference to FIG.

In the figure, DI to D17 are write data, ECC
is an error correction code, Pd is padding data, ■ is a tape mark identification number, '■, ■ is a data block identification number, and ■ is a data block identification number check flag, respectively.

The data format on the magnetic tape medium 1 shown in FIG. 18-20). Note that each data group (18 to 20) for each zone is composed of 8 hide data.

In this embodiment, the write data transferred from the host device (not shown) is 17 heights, so;
? - Insufficient data bytes to form the data group 19 are added as padding data Pct.

In the data writing according to this embodiment, when the write data of the odd numbered hide is transferred from the host device (not shown) to the magnetic tape control device 5, the data is written in the A zone data group 16.
On the other hand, the even-numbered Hyde write data is distributed to the B zone data group 17 side. The write data allocated to each zone is separated into 7-height write data data groups 18 and 19 for each zone, and each data group is further divided into error correction codes (F, CC) that are check data for error correction. ”) is added with 1 hide, resulting in 8 hides.

After the data groups 18 and 19, a residual data group 20 and a CRC data group (not shown) are further added.

Data according to the present invention is recorded in the first to fourth bytes of the residual data group 20.

The tape mark identification number ■ is recorded in the first hide, the data block identification numbers ■, ■ are recorded in the 2.3rd byte, and the flag ■ for checking the data block identification number is recorded in the fourth hide.

The above 4 hides are A zone data group 16. The same data is written in both B zone data groups 17.

Also, by importing the same data, the writing of block management information is divided into two parts, and it is possible to recognize the block management information of at least one zone.

(g) Effects of the Invention As described above, hardware can detect skipped data blocks due to various factors or skipped files due to skipped tape marks at an early stage, and automatically transfer them to the regular data program. By positioning the block management method as such, it is possible to provide a block management method that can ensure high reliability of recorded/reproduced information.

[Brief explanation of drawings]

FIG. 1 shows a conventional data block management method on a magnetic tape, FIG. 2 shows a magnetic tape block management method according to an embodiment of the present invention, and FIG. 3 shows a magnetic tape according to an embodiment of the present invention. FIG. 4 shows an example of a data format on a magnetic tape medium according to the present invention. In the figure, 1 is a magnetic tape medium, 2 is a data block (a), 3 is a tape mark, and 4 is a data block (b)
, 5 is a magnetic tape control device, 6 is a magnetic tape device, 7 is an interface circuit, 8 is a multiplexer circuit, 9 is a buffer circuit, 10 is a modulation/write circuit, 11 is a demodulation/read circuit, 12 is an SNS circuit, 13 is a SN generation circuit, 1
4 is comparator times 17&, 15 is Ml) U, 16 is A zone cheetah group, 17 is B zone data group, 18
is data group (i), 19 is data group (ii)
). 21 indicates residual data groups, respectively.

Claims (1)

[Claims] In a recording medium in which a data block, which is a physical recording processing unit, is a management unit and a data file is made up of a predetermined number of data blocks, when recording information on the recording medium, the data block is divided into data file units. A tape mark identification number is recorded for each tape mark recorded for separation, and a data block identification number is recorded for each data block between the tape marks. A block management method characterized by detecting skipped reading of the data block or the data file based on information.