JP2581003B2 - Recording disk controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording disk control device, and more particularly to a recording disk control device for imitating a recording disk device as a magnetic tape device.

[0002]

2. Description of the Related Art Generally, in a large-scale computer system, a magnetic disk device is used as a randomly accessible file device having a large-scale storage capacity. Then, in preparation for the deletion of a file due to a failure of the magnetic disk device or an erroneous operation, the data recorded in the magnetic disk device is copied to a magnetic tape for backup. Regarding this data backup, a number of software programs have been developed for backing up data to magnetic tapes according to the respective tasks and data volumes.

On the other hand, rewritable magneto-optical disks have been put to practical use as higher-density storage media. This greatly exceeds the storage density of the magnetic disk, and the device can be made compact. Therefore, focusing on a magneto-optical disk as a large-capacity, high-density storage medium, it is useful as a data backup medium.

[0004]

In a large-scale computer system, a considerable number of magnetic disk devices are used, and the number of magnetic tape media for backing up data in these magnetic disk devices is also considerable. . Moreover, since it is common to manage not only one generation but also several generations of backup, there is an inconvenience that the amount of magnetic tape medium that is comparable to the storage capacity of the entire magnetic disk is often insufficient.

For example, assuming a system using 1,000 magnetic disks having a storage capacity of 1.5 Gbytes, the total capacity is 1500 Gbytes. The storage capacity of a cartridge type magnetic tape medium used in a general-purpose computer is 0.4 GB per volume, and if a backup is to be made, 4000 volumes are required as 4 volumes per magnetic disk, and 2 more volumes are required. When managing generations, the volume is 8000 volumes. 5.25 of ISO standard
Since the size of an inch type magneto-optical disk is 644 Mbytes per disk, it is 6000 for three magnetic disks per disk.
It becomes the scale of the piece. In recent years, the capacity of 3.5-inch magneto-optical disks has been increasing.

Comparing the “weight × volume” of the magnetic tape medium and the “weight × volume” of the magneto-optical disk medium, the magneto-optical disk is a fraction to one-tenth of the current apparatus configuration.
About. For these reasons, there is a demand to use a magneto-optical disk as a backup storage medium. Furthermore, from the user's point of view, there is also a demand that if the function is the same as a backup, it is to be treated in the same manner as a magnetic tape that has been used so far.

[0007] That is, it is desired to use a magneto-optical disk or the like as a backup storage medium, but in this case, there is a disadvantage that software for backup to a magnetic tape that has been accumulated so far cannot be used.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording disk control device which can solve the disadvantages of the prior art and, in particular, can make a recording disk device act as a magnetic tape device for a host device. That is its purpose.

[0009]

According to the present invention, there is provided a data buffer unit for temporarily storing data relating to data transfer between a host device and a recording disk device,
A transfer control unit for a high-order device that adds a block boundary to data received from the high-order device and accumulates the data in a data buffer unit;
A positioning control unit for storing the data stored in the data buffer unit in the recording disk device, receiving the data stored in the recording disk device, and storing the data in the data buffer unit.

In addition, the positioning control section sequentially updates the address of the data being transferred in the data buffer section as the head position address in the control memory, and the position control section records the data at the block boundary in the data buffer section. A control data management means for sequentially updating the control data in the control memory; a head position address for receiving various commands from a host device as a head position for the magnetic tape; Tei and a traveling imitation means for controlling the data transfer between the data buffer unit and the recording disk apparatus based
You.

In addition, the transfer control unit for the host device is
Block where the data block of the data received from the
Data block that adds a data block flag to the block boundary
And means for adding data received from the host device.
Create sector boundaries in units of the recording disk sector size.
Means for generating sector boundaries, and
Sector number adding means for adding a
When the data block received from it exceeds the sector size
Continuation flag adding means for adding a continuation flag to a sector boundary
When the sector size is not exceeded,
Terminating flag adding means for adding a terminating flag,
The configuration is adopted.

According to the second aspect of the present invention, the transfer control unit for the higher-level device includes a BOT flag adding means for adding a BOT flag to a block boundary added to the first sector of the recording disk, and a running simulation. A BOT search function for sequentially reading data from the first sector of the recording disk when receiving a rewind command from a higher-level device and writing the data to the data buffer; A configuration is provided in which a BOT positioning function is provided for outputting the address of the block boundary to which the BOT flag has been added to the address management means as a head position address.

According to the third aspect of the present invention, when a data write command and data are received from a higher-level device, the transfer controller for the higher-level device adds a continuous block number for each data block of the data to a block boundary. Block number adding means, and a tape mark flag adding means for adding a tape mark flag to a block boundary when a tape mark writing command is received from a higher-level device.

According to the fourth aspect of the present invention, when the running simulating means receives a positioning command for a tape mark position, a block number, or the like from a higher-level device , the running dummy production means performs a search in the search direction based on the positioning command from the head position address of the data buffer unit. A buffer position search function for searching for a position, and, when the position is not searched by the buffer position search function, reading the data of the recording disk from the sector following the sector number at the sector boundary to which the head position address belongs, and reading the data. A configuration is provided in which a tape position search function for storing the data in the buffer unit is provided.

The present invention aims to achieve the above-mentioned object by these means.

Here, the recording disk refers to a write-once, large-capacity recording medium such as a magneto-optical disk or an optical disk, and the recording disk device writes data to the magneto-optical disk or the like. Device that reads data from

[0017]

According to the first aspect of the present invention, at the time of processing for storing data from a higher-level device in a recording disk device, the higher-level device transfer control unit first adds a block boundary to data received from the higher-level device. Then, the positioning control unit stores the data temporarily stored in the data buffer unit in the recording disk device. At this time, in the positioning control unit, the address management unit sequentially updates the address of the data being transferred in the data buffer unit as the head position address in the control memory. That is, the address on the buffer of the data being accumulated in the data buffer unit by the transfer control unit for the host device is sequentially updated in the control memory as the head position address. Hereinafter, this head position address is
It is treated as the head position for the magnetic tape.

Then, the running simulation means controls the data transfer between the data buffer unit and the recording disk device based on the control data in the control memory. That is, the data in the data buffer section is output to the recording disk based on the control data such as the head position address. At this time, the positioning control unit manages the use of the data buffer unit having a finite storage capacity by processing the data transfer using the head position address.

On the other hand, when reading the data stored on the recording disk and transferring the data to the host device, the running simulating means outputs a read command to the recording disk device and reads the data stored on the recording disk. The data is received from the recording disk device and stored in the data buffer unit. At this time, the control data management means sequentially updates the control data recorded on the block boundary in the data buffer unit into the control memory. The control data recorded at the block boundary is, for example, a block number, and the content of the control data differs depending on the type of the magnetic tape to be emulated.

Subsequently, the transfer control unit for the higher-level device transfers the data temporarily stored in the data buffer unit to the higher-level device. At this time, the positioning control unit successively updates the control memory with the address on the buffer of the data being accumulated in the data buffer unit by the running simulation unit as the head position address. In response to this, the upper device data transfer control unit transfers the data in the data buffer unit to the upper device based on the control data read from the block boundary and the value of the head position address and the like. At this time, for example, even if the data is stored on the recording disk with a data length different from that of the magnetic tape medium, the data is edited to the data length of the magnetic tape by a process based on the control data read from the block boundary and transmitted to the higher-level device. Transferring. In addition, by using the head position address to process data transfer, the use of a data buffer unit having a finite storage capacity is managed.

Moreover, the data block flag adding means adds a data block flag to a block boundary where the data block starts, when storing the block data in the data buffer section. The sector boundary generating means generates a sector boundary in data received from a higher-level device in units of a sector size of the recording disk. Subsequently, the continuation flag adding unit adds a continuation flag to a sector boundary when the data block to be stored in the data buffer unit exceeds the sector size, and on the other hand, when the data block does not exceed the sector size, the termination flag adding unit includes: An end flag is added to a sector boundary.

According to the second aspect of the present invention, when the upper-level device transfer control unit is accumulating data from the higher-level device in the data buffer unit, the BOT flag adding unit sets the received data to the recording buffer. If the data is recorded in the first sector of the disk, a BOT flag is added to the block boundary immediately before the data.

On the other hand, when the running simulating means receives a rewind command from a higher-level device for a recording disk having a BOT flag added to a block boundary, the BOT search function performs
Data is read out from the first sector of the recording disk in order and written to the data buffer. Subsequently, the BOT positioning function outputs the address of the block boundary to which the BOT flag has been added to the address management means as the head position address.

According to the third and fourth aspects of the present invention, in the process of storing the data in the data buffer unit by the transfer control unit for the higher-level device, the block number adding means sets the continuous block number for each data block of the data. Add to the block boundary area. The tape mark flag adding means adds a tape mark flag to a block boundary when receiving a tape mark write command from a host device. When the positioning control unit receives a positioning command for a tape mark position, a block number, or the like from a higher-level device for a recording disk having a block number or a tape mark indicating the end of a file added to a block boundary as described above. First, the in-buffer position search function searches the head position address in the data buffer unit in the search direction according to the positioning instruction from the head position address.

Further, the tape position search function reads the data of the recording disk from the sector following the sector number at the sector boundary to which the head position address belongs when the position is not searched by the buffer position search function. Store in the department. For the data newly stored in the data buffer unit, the in-buffer position search function searches the position according to the positioning instruction as described above. This search is actually performed on various types of control data described on the block boundaries output to the control memory by the control data management means.

[0026]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing the configuration of the present embodiment. The recording disk controller 2 temporarily stores data relating to data transfer between the higher-level device 1 and the recording disk device 3, and adds a block boundary to data received from the higher-level device 1. The transfer control unit 5 for the host device that stores the data stored in the data buffer unit 4 and the data stored in the data buffer unit 4 is stored on the recording disk 3A, and the data stored on the recording disk 3A is received. A positioning control unit 6 for storing the data in the data buffer unit 4.

The storage capacity of the data buffer unit 4 is an integral multiple of the data length handled by the recording disk device 3 to facilitate various processes. Upper device transfer control unit 5
Edits data given in an output format from the host device 1 to the magnetic tape device as data that can be handled by the recording disk device 3. The data stored in the data buffer unit 4 is edited into an output format of a magnetic tape device and transferred to the host device 1. Further, the higher-level device transfer control unit 5 outputs a control command for positioning the magnetic tape device from the higher-level device 1 to the positioning control unit 6 provided therewith. The positioning control unit 6 controls data transfer between the data buffer unit 4 and the recording disk device 3. At this time, the recording disk device 3 is emulated as a magnetic tape device with respect to the host device 1 by the following various means via the data buffer unit 4.

The positioning control unit 6 includes an address management unit 8 for sequentially updating the address of the data being transferred in the data buffer unit 4 as a head position address 26b in the control memory 7, and a block boundary in the data buffer unit 4. A control data management means 10 for sequentially updating the control data recorded in the control memory 7 to the control memory 7, and accepting various commands from the host device 1 with the head position address as the head position for the magnetic tape, and receiving the various commands and control commands. There is provided running simulation means 9 for controlling data transfer between the data buffer unit 4 and the recording disk device 3 based on the control data in the memory 7.

FIG. 2 shows a configuration corresponding to claim 2. Here, BOT is handled as control data, and the upper-level device transfer control unit 5 sets the BOT flag 2 at the block boundary added to the first sector of the recording disk 3A.
BOT flag adding means 5A for adding 72 and data block flag adding means 5B for adding a data block flag 273 to a block boundary where a data block of data received from the host device 1 starts.

In response to these flag adding means, the running simulating means 9 reads out data sequentially from the first sector of the recording disk 3A when receiving the rewind command from the host device 1, and stores the data in the data buffer. A BOT search function 9A for writing to the unit 4 and a BOT positioning function for outputting the address of the block boundary to which the BOT flag is added when the data is accumulated in the data buffer unit 4 to the control data management unit 10 as a head position address. 9B.

This will be described in detail. In this embodiment, the above-described units are realized by the hardware resources shown in FIG. Here, the magneto-optical disk device 3 is used as a recording disk device. The storage medium of the magneto-optical disk device 3 is formatted in a fixed-length format divided into sectors, has data blocks as data recording / reproducing units, and has a header as an identifier attached to each data block. Have been. The arrangement of the data blocks may be a cylinder type arranged in concentric circles such as a magnetic disk medium, or a spiral type arranged in a spiral shape. The data buffer unit 4 is constituted by a RAM (random access memory).

The recording disk control device 2 includes a microprocessor unit 24 for controlling the magneto-optical disk device 3 in accordance with an input / output command issued by the host system 1, and receives an input / output command from the host system 1 as a host device. The host interface control unit 21 and the data buffer unit 4 are driven to perform data reception and data transfer, and the disk interface control unit 22 and the data buffer unit are used to read / write data to / from the magneto-optical disk device 3. 4 is driven.

In this embodiment, the microprocessor section 24
Address table 26 according to emulator code 25
By operating the pointer table 27 and the pointer table 27, the magneto-optical disk device 3 appears to the host system 1 as a magnetic tape device. Emulator code 2
Reference numeral 5 denotes a microprogram code in which a processing procedure for operating the microprocessor unit 24 is described. The microcomputer 5 decodes an input / output instruction issued by the host system 1 and sets the magneto-optical disk device 3 so as to meet the instruction processing purpose. It is configured to control and emulate a magnetic tape device. By performing various controls based on the emulator code 25, the microprocessor unit 24 also operates as the positioning control unit and the transfer control unit for the host device described above, and executes various units.

When the apparatus is powered on, the emulator code 25 generates an address table 26 and a pointer table 27 in the control memory 7 of the microprocessor section 24. The address table 26 is a table for managing values used for various controls such as a head position address and a sector number, and is generated and used by the positioning control unit 6. On the other hand, the pointer table 27 is a table for managing values to be added to the magneto-optical disk 3A, such as the data block flag 27c, and the upper device transfer control unit 5 adds the data block flag 27c to the data received from the higher device 1. ing. The control data management means 8 outputs the content of the control data described on the block boundary read from the recording disk 3A to the pointer table 27. An example of the pointer table 27 is shown in FIG. 4A, and an example of the address table 26 is shown in FIG.

The checksum code 27h is added for the purpose of verifying the contents of the pointer table 27, and is a result of binary addition of the contents of the table in units of 2 bytes. In the following description, the checksum code 27h is sequentially updated, but the description is omitted.

Next, the operation of the recording disk device 2 will be described.

To output data from the host device 1 to the magneto-optical disk 3A, first, the host device transfer control unit 5
Adds a block boundary to data received from the host system 1 via the host interface 21 and stores the data in the data buffer unit 4. The block boundary is generated when a data block ends or when a command to record various control data on a magnetic tape is received. During the data accumulation, the address management means 10 sequentially updates the address of the accumulated data in the buffer as the head position address 26b in the address table 26 of the control memory 7. Thereafter, the emulator code treats the head position address 26b as the head position for the magnetic tape.

Subsequently, the running simulator 9 outputs the data in the data buffer unit 4 to the magneto-optical disk drive 3 via the disk interface 22 based on the control data such as the head position address 26b. For example, when the data buffer address 26g, which is the upper limit of the storage capacity of the data buffer unit 4, and the head position address 26b match, the upper device transfer control unit 5 sends the data buffer unit 4
A request is made to temporarily suspend the output to the data buffer unit 4, and then the data stored in the data buffer unit 4 is output to the magneto-optical disk device 3.

On the other hand, when reading the data stored on the magneto-optical disk 3A and transferring the data to the host device 1, first, the running simulator 9 outputs a read command to the magneto-optical disk device 3 via the disk interface 22. After that, the data stored in the magneto-optical disk 3A is received from the magneto-optical disk device 3 and stored in the data buffer unit 4. At this time, the control data management means 8 sequentially updates the control data recorded at the block boundaries in the data buffer unit 4 in the control memory 7.

Subsequently, the upper-level device transfer control unit 5 transfers the data temporarily stored in the data buffer unit 4 to the higher-level device 1 via the host interface 21. At this time, the address management means 10 sequentially updates the control memory 7 with the head address 26b of the address on the buffer of the data being accumulated in the data buffer unit 4 by the running simulation means 9. In response to this, the upper-level device transfer control unit 5 transfers the data in the data buffer unit 4 to the higher-level device 1 based on the control data read from the block boundary and values such as the head position address. In this transfer, for example, even if the data is stored on the magneto-optical disk 3A with a data length different from that of the magnetic tape medium, the upper-level device transfer control unit 5 performs processing based on the control data read from the block boundary, The data is edited to the data length of the magnetic tape and transferred to the host device.

(Operation Example of Emulating BOT)

Various control data are added to the block boundaries by the transfer control unit 5 for the host device. For a magnetic tape, a BO indicating a recordable start position of the magnetic tape is used.
T marker is stuck on the back side of the magnetic tape,
This BOT (Beginning of Tape)
Are used as recording / reproduction start positions. Therefore, in this embodiment, it is necessary to receive and process various commands based on the BOT from the host device. Here, the task is to respond to a rewind command for the BOT.

In the embodiment corresponding to the second aspect, when the upper-level device transfer control unit 5 stores data from the higher-level device in the data buffer unit, the BOT flag adding unit 5A transmits the received data. Is recorded in the first sector of the magneto-optical disk, a BOT flag is added to the block boundary immediately before the data.

When the running simulating means 9 receives a rewind command from the host device 1 for the magneto-optical disk 3A with the BOT flag added to the block boundary, the BOT search function 9
A reads data sequentially from the first sector of the magneto-optical disk 3A and writes the data to the data buffer unit 4. Subsequently, the BOT positioning function 9B outputs the address of the block boundary to which the BOT flag is added to the address management unit 10 as the head position address 26b. As described above, in this embodiment, in order to emulate the processing related to BOT,
It is possible to make the magneto-optical disk device behave as if it were a magnetic tape to the host device. In addition, since the search for the first sector of the magneto-optical disk 3A by the magneto-optical disk device is a direct access, there is no need for a rewind time like a magnetic tape, and the rewind processing for the BOT is significantly faster than for a magnetic tape. This also has the effect of being able to be performed. In a normal magnetic tape device, control data such as a recording density is written between the BOT and the first data block. In the present embodiment, the magnetic tape is written between the BOT and the data block. Since it is not necessary to record control data for recording the data, the time from the BOT position to the start of data reproduction can be greatly reduced.

(Example of operation for emulating a data block)

In the magnetic tape, recording is performed after the running speed of the tape becomes constant, so that an area where data is not recorded occurs in a portion corresponding to the time required for accelerating the tape. In order to prevent uneconomics due to the occurrence of an area where no data is recorded, records from a host device are divided into blocks based on a blocking coefficient, and the data blocks are recorded on a magnetic tape medium.
Therefore, in this embodiment, it is necessary to receive and process various instructions based on the data block from the host device. An operation example of emulating this data block will be described below. Here, the transfer control unit 5 for the higher-level device may receive the blocking coefficient and block the data, or the data may be received after the data is blocked by the higher-level device. Shall be. Therefore, an example of processing performed when the upper-level device transfer control unit 5 accumulates data blocks in the data buffer unit 4 will be described. Here, it is an object to match the relationship between the length of the data block, the capacity of the data buffer unit, and the recording unit of the recording disk.

In this embodiment , the transfer control unit 5 for the host device
A data block flag adding means 5B for adding a data block flag to a block boundary at which a data block of data received from the host device starts, and a data block from the host device 1 for storing data received from the host device 1 in units of a sector size of the magneto-optical disk 3A. Sector boundary generating means 5C for generating a boundary
And a continuation flag adding means 5D for adding a continuation flag to a sector boundary when the data block received from the host device 1 exceeds the sector size, and a termination flag addition for adding a termination flag to the sector boundary when the data block does not exceed the sector size. Means 5E.

This will be described in detail. FIG. 5 shows a logical tape image created in a physical data block of a sector of a magneto-optical disk medium. FIG. 5A shows an example in which data of consecutive sector numbers are recorded in the data buffer memory, and FIG. 5B shows the data configuration in each sector. The upper-level device transfer control unit 5 stores data of consecutive sectors to be written in the data buffer unit 4 as indicated by reference numerals 340 to 344. Further, the running simulating means 9 receives the data of the continuous sector to be read from the magneto-optical disk device 3 and
The data is stored in the data buffer unit 4 as 0 to 344.

The number of continuous sector ranges generated / stored in the data buffer unit 4 is K + 1. In this embodiment, in order to control the data in the K + 1 sector range as an access unit to the magneto-optical disk device 3, data is written to or read from K + 1 consecutive sectors at a time. Therefore, the generated /
The continuous sector number (logical sector number) of the stored leading sector data 340 is an integral multiple of K + 1.

The ECC 301 is an error correction code generated / checked by the magneto-optical disk device 3 and is not directly visible to the recording disk control device 2. The header as the above-mentioned identifier is also used for control inside the magneto-optical disk device 3 to identify the data block, and is not directly visible to the recording disk control device 2. Therefore, in the data transfer between the data buffer unit 4 and the magneto-optical disk device 3, the net data of the data block is processed.

The format constructed in the sector data will be described. A sector boundary (310, 315, 317) area is placed at the head of each sector data, and a block boundary (311, 31) is located immediately before the tape format data block.
3) The area is placed. In addition, a block boundary (31
9, 320, 321). These block boundaries are stored in the pointer table 27 shown in FIG.
Is written by the upper device transfer control means. This format is secured by the microprocessor unit 24 based on the emulator code 25 that operates as the transfer control unit 5 for the host device.

The sector boundary generation means 5C of the upper-level device transfer control unit 5 converts the data received from the higher-level device 1 into sector boundaries (31) in units of the sector size of the recording disk 3A.
0, 315, 317). A sector number is added to this sector boundary. Subsequently, the continuation flag adding unit 5D adds a continuation flag to a sector boundary when the data block to be stored in the data buffer unit 4 exceeds the sector size. On the other hand, when the data block does not exceed the sector size, the termination flag adding means adds a termination flag to a sector boundary. By adding the continuation flag and the end flag to the sector boundaries in this manner, the transfer control unit 5
Can reproduce the data blocks on the magnetic tape regardless of the storage capacity of the data buffer unit 4 or the recording format of the recording disk. In other words, the complication of processing caused by the type of recording disk is absorbed by generation of sector boundaries and addition of flags.

(Operation Example of Emulating Positioning Instruction)

The magnetic tape device includes a device for assigning a sequential block number to each of the above-described data blocks, and a higher-level device for such a device reproduces data with a specific block number. May issue an instruction to position the data block at the head of the block number. In addition, there is a magnetic tape device that gives a tape mark when one file ends in units of a file. In this case, the upper device also issues a command to search for and position the tape mark. Therefore, in this embodiment, it is necessary to receive and process such a positioning command from the host device.
An operation example of emulating this positioning instruction will be described below. Here, it is an object to store a block number, a tape mark, and the like on a recording disk, and to match a search method when a command is received with a data buffer.

In an embodiment corresponding to the third and fourth aspects ,
Block number adding means 5F for adding a continuous block number for each data block of the data to a block boundary area when receiving a data write command and data from the higher-level device; And a tape mark flag adding means 5G for adding a tape mark flag 271 to a block boundary when a tape mark write command is received from the CPU.

In response to this, when the simulated running means 9 receives a positioning command for a tape mark position, a block number, or the like from a host device, the running dummy manufacturing means 9 moves from the head position address 26b of the data buffer unit 4 in the search direction according to the positioning command. A buffer position search function 9C for searching a position, and a sector following a sector number of a sector boundary to which the head position address 26b belongs when the position is not searched by the buffer position search function 9C, the magneto-optical disk 3
A tape position search function 9D for reading out the data of A and storing it in the data buffer unit 4 is provided.

The block number adding means 5F adds a continuous block number for each received data block to the block boundary area. Tape mark flag adding means 5
G adds a tape mark flag to a block boundary when receiving a tape mark write command from a higher-level device. For the recording disk in which the block number and the tape mark indicating the end of the file are added to the block boundary, the in-buffer position search function 9C first searches the head position address of the data buffer unit 4 by the positioning command. Search for the position in the direction.

Further, when the position is not searched by the in-buffer position search function 9C, the tape position search function 9D follows the sector number of the sector boundary at the end of the data buffer section 4 to which the head position address 26b belongs. The data on the recording disk 3A is read from the sector and stored in the data buffer unit 4. As described above, the in-buffer position search function 9C searches the data stored in the data buffer unit 4 for the position according to the positioning instruction. This search is actually performed on various control data described on the block boundaries output to the control memory 7 by the control data management means 8.

When a position related to an instruction from the higher-level device 1 is found in the data buffer unit 4, the address management means 10 sets the address of the block boundary to which the flag indicating the position has been added as the head position address 26b. Therefore, the transfer control unit 5 for the higher-level device performs a process of reproducing data following the block boundary. In the present embodiment, since such operation is performed when a positioning command is received, a magneto-optical disk or the like behaves as a magnetic tape device even in a higher-level device on the premise of a magnetic tape using a tape mark or a block number. Can be made.

(Control data)

Next, each of the above-described embodiments will be described again based on the control data recorded in the control memory. Here, the contents of the control memory shown in FIG. 4 which are referred to as needed in the above description of each function are defined, and the situation indicated by the value of each variable will be described.

(Pointer Table)

When the tape mark flag 27a is set and the other flags are in the reset state, it indicates that the block boundary corresponds to the tape mark of the magnetic tape format and is a tape mark.

When the BOT (tape start) flag 27b is set and the other flags are in the reset state, the block boundaries correspond to the magnetic tape format BOT marker (where the mark indicating the tape start is marked). Indicates that it is a marker.

When the data block flag 27c and the end flag 27e are set and the other flags are in the reset state, the block following the block boundary corresponds to the data block for the magnetic tape format, which is the data block. It shows that. In addition, this indicates that the data block ends within the sector data area where the block boundary is located.

When the data block flag 27c and the continuation flag 27d are set and the other flags are in the reset state, the data block area next to the block boundary continues to the first data block in the next sector data area. It is shown that. The data block size 27g is valid when the data block flag 27c is set, and indicates the byte length of the data block placed next to the block boundary in binary.

When the continuation flag 27d is set and the other flags are in the reset state, it is determined that the continuation of the last data block in the immediately preceding sector data area continues to the next data block on the block boundary. In addition to the display, it indicates that the data is continued at the head data block of the next sector data area.

When the continuation flag 27d and the termination flag 27e are set and the other flags are in a reset state, it indicates that the data block is completed in the next data block on the block boundary. When the end flag 27e is set and the other flags are in the reset state, it indicates that this block boundary is the last information recorded and that no significant information exists thereafter.

FIG. 6 shows an example of the relationship between the combinations of the above-mentioned flags and the block boundaries in FIG. Here, the logical value “1” means set, and “0” means reset state.

The data block 312 shown in FIG. 5 is completed and is not continued in another sector data area. Further, the data block 314, the data block 316, and the data block 318 continue, and it can be identified from the combination of the flags in FIG. 6 that these constitute one logical data block.

The block number 27f is a binary display serial number unconditionally given to all block boundaries. When the block number 27f overflows, it is returned to zero, and a number is cyclically assigned.

(Address table)

Next, the address table 26 shown in FIG. 4B will be described. The address table 26 is for managing the position of data stored in the data buffer unit 4 and the sector number, and displays the position on the data buffer unit 4 of the block boundary indicated by the pointer table 27 by the head position address 26b. The head position of the sector on the data buffer unit 4 is set to the sector boundary address 26d.
, And the sector number of the sector indicated by the pointer table 27 is displayed as a logical sector number 26a.

The contents of the pointer table 27 are copies of the contents of the block boundaries constructed in the sector data stored in the data buffer unit 4. The head position address of the address table 26 is controlled so as to give an address on the data buffer unit 4 where the block boundary exists.

(Various commands from host device)

The operation of the microprocessor section 24 based on the emulator code 25 relating to input / output instructions will be described below, focusing on operations on the control memory 7.

First, since the mounting of the magnetic tape medium in the apparatus corresponds to the mounting of the magneto-optical disk medium in the apparatus, it is assumed that the magnetic tape medium has already been mounted and is in the ready state. When the magneto-optical disk 3A is mounted on the magneto-optical disk device 3, the upper-level device transfer control unit 5 initializes the pointer table 27. All the flags 27a to 27d are reset, and the values of the block number 27e and the data block size 27f are set to “0”. Similarly, the positioning control unit 6 initializes the address table 26 to zero.

Now, since the host system 1 intends to access the magnetic tape device, it issues an input / output command for the magnetic tape. At that time, the recording disk control device 2
According to the program of the emulator code 25, the microprocessor unit 24 controls as follows.

The REWIND instruction sets the magnetic tape to BOT.
(Tape start) This is an instruction to rewind to the marker. In this regard, logical sector number 2 in address table 26
6a is set to zero, the head position address 26b and the sector boundary address 26d are set to the head address of the data buffer unit 4, and data from sector 0 to sector K is read from the magneto-optical disk 3A to the data buffer unit 4 as shown in FIG. The contents of the block boundary indicated by the head position address 26b are initialized and stored in the pointer table 27. In this initialization, the BOT flag 27b is set to '1'.

When the BOT flag 27b is "1",
Further, when an input / output command for rewinding the tape is issued, a BOT status status is reported for the command and the command is terminated.

The WRITE command is a command for writing a series of data received from the host system 1 in a forward direction as a data block. In this regard, the current address table 26 and the pointer table 27 which is a copy of the block boundary indicated by the address table 26 are controlled as follows.

If the BOT flag 27b is "1", the address table 26 and the pointer table 27 are advanced to the next block boundary, and the processing is performed again. At this time, the block number 27f is incremented by one. The head position address 26b is also advanced by the block boundary size.

Tape mark flag 27a... '0', B
OT flag 27b... '0', data block flag 27
c ... '1', continuation flag 27d ... '0', end flag 2
The pointer table 27 is updated with the contents of 7e... '1', data block size 27g... Then, the data of the WRITE instruction is written from the next data buffer unit 4 area by a data block size of 27 g. At this time, the data of the WRITE instruction has a data block size of 2
If it is less than 7 g, the number of transferred data bytes is stored in the data block size 27 g and reflected in the data buffer unit 4. If the data of the WRITE instruction exceeds the data block size 27 g, the continuation flag 27 d is updated to “1” and the end flag 27 e is updated to “0” and reflected in the data buffer unit 4 to generate the next block boundary. For this purpose, the contents of the pointer table 27 and the address table 26 are updated as follows.

Data block flags 27c... '0', continuation flags 27d... '1', end flags 27e.
Block number 27f: increment by 1, data block size 27g: provisional number of bytes to next sector boundary, logical sector number 26a: increment by 1, sector boundary address 26d: increment by sector size, head position address 2
6b: Match with the sector boundary address 26d.

Subsequently, the contents of the pointer table 27 are written in the data buffer section 4 indicated by the head position address 26, and
The data of the remaining WRITE instruction is written by the data block size 27g from the subsequent data buffer unit 4 area.
If the data block size is less than 27 g, the number of remaining transferred data bytes is converted to the data block size 27 g.
And reflected in the data buffer unit 4.

When the data writing of the WRITE instruction is completed, the block boundary 321 in FIG. 1 is written. Of course, the pointer table 27 and the address table 26 are also updated. Next, when a WRITE instruction is issued again, control is performed so as to update from the block boundary indicated by the address table 26.

The READ instruction is an instruction for reading data of the next data block detected in the forward direction and transferring the series of data to the host system 1. In this regard, control is performed as follows based on the contents of the pointer table 27 which is a copy of the block boundary indicated by the current address table 26.

If the BOT flag 27b is "1", the address table 26 and the pointer table 27 are advanced to the next block boundary, and the processing is performed again.

If the tape mark flag 27a is "1", the process proceeds to the next block boundary, a tape mark detection status is reported in response to a READ command, and the READ command is terminated.

If the data block flag 27c is '1', the data in the data buffer unit 4 following this block boundary is transferred to the data block size 27g. However, if the continuation flag 27d is “1”, the termination flag 27e
Is read up to the data block following the block boundary where is "1".

If the value of the logical sector number 26a exceeds the value of the EOT logical sector number 26e, an EOT (end of tape) status is reported after the data transfer of the READ command, and the READ command is terminated.

When the value of the logical sector number 26a exceeds the value of the upper limit logical sector number 26f, an error is reported for all instructions in the forward direction.

The WRITE TAPE MARK instruction is
This is a forward instruction for writing a tape mark indicating a file boundary. In this regard, the current address table 26
And the pointer table 27, which is a copy of the block boundary pointed to, is controlled as follows.

If the BOT flag 27b is "1", the address table 26 and the pointer table 27 are advanced to the next block boundary, and the processing is performed again.

Tape mark flag 27a... '1', B
OT flag 27b... '0', data block flag 27
c ... '0', continuation flag 27d ... '0', end flag 2
The pointer table 27 is updated with the contents of 7e... '0' and the data block size 27g...

Head position address 26b: Step by the block boundary size, update the pointer table 27, and generate a block boundary 321 as shown in FIG. 1 as a block end.

FORWARD which is another input / output instruction
SPACE BLOCK, BACK SPACE BL
OCK, FORWARD SPACE TO TAPE
MARK, BACKSPACE TO TAPE M
ARK and the like can be controlled in the same manner as described above.

Next, data management of the data buffer unit 4 will be described. The program of the emulator code 25 checks whether or not the value of the head position address 26b exceeds the head position address upper limit value 26g in the process of proceeding in the forward direction in the aforementioned input / output instruction.

If it exceeds, if it is a WRITE command, K + 1 sector data in the data buffer unit 4 is written back to the magneto-optical disk device 3. If READ or S
If it is a PACE instruction, the next K + 1 sectors are read from the magneto-optical disk 3 and stored in the data buffer unit 4.

Conversely, when the value of the head position address 26b must be updated to a value equal to or less than a predetermined value (the lower limit of the head position address) in the input / output command in the reverse direction (rewinding the tape), the K + 1 A series of sector data having a sector number from “current sector number− (K + 1)” to “current sector number−1” is stored in the data buffer unit 4.

As described above, according to the embodiment, the sector data in the magneto-optical disk drive is expanded in the large-scale data buffer section, and a block boundary area is provided for the data to provide a tape mark flag, a BOT mark flag, and a data. Since the block flag and the data block size can be displayed, the upper system can treat the magneto-optical disk device as a magnetic tape device.

Here, the sector boundary and the block boundary are described separately, but they are treated the same when actually creating the emulator code.

Further, by embodying the present recording disk controller together with a disk controller for a subsystem that controls a plurality of magneto-optical disks, the emulation of the magnetic tape device according to the present invention can be performed in a sub-system of the magneto-optical disk. It can be implemented in a system.

[0104]

According to the first aspect of the present invention, the transfer control unit for the higher-level device adds a block boundary to data received from the higher-level device and accumulates the data in the data buffer unit. Since the data temporarily stored in the data buffer unit is stored on the recording disk, the data can be output to the recording disk together with the block boundaries generated in the data buffer. Moreover, since the address management means sequentially updates the address of the data being transferred in the data buffer section as the head position address in the control memory, the head position address can be treated as the head position for the magnetic tape. Therefore, a magnetic tape that is sequentially accessed can be simulated using the data buffer that is directly accessed. Further, the running dummy production means controls the data transfer between the data buffer unit and the recording disk device based on the head position address in the control memory, so that the storage capacity of the data buffer unit is effectively utilized. Data transfer can be performed. As described above, it is possible to provide an unprecedented extremely excellent recording disk control device that can make the recording disk device behave as a magnetic tape device while effectively utilizing hardware resources.

According to the second aspect of the present invention, when the higher-level device transfer control unit is accumulating data from the higher-level device in the data buffer unit, the BOT flag adding unit sets the received data to the recording device. If the data is recorded in the first sector of the disk, a BOT flag is added to the block boundary immediately before the data, and when a rewind command for such a recording disk is received, the BOT search function performs the recording. Data is read out in order from the first sector of the disk for use and written into the data buffer, and then BOT
Since the positioning function outputs the address of the block boundary to which the BOT flag has been added to the address management means as a head position address, the command from the host device is based on the tape start position (BOT) for the magnetic tape. However, it is possible to provide an unprecedented excellent recording disk control device that can make the recording disk device behave as a magnetic tape device.

In particular, in the present invention described in claims 1 and 2,
The data block flag adding means adds a data block flag to a block boundary at which the data block starts, when storing the blocked data in the data buffer unit, and the sector boundary generating means receives the data block from the host device. Since sector boundaries are generated in units of the sector size of the recording disk with respect to the set data, the data blocks on the magnetic tape can be accurately handled and edited into the data format of the recording disk. Moreover, the continuation flag adding means adds a continuation flag to a sector boundary when the data block to be stored in the data buffer exceeds the sector size, so that the data block for the magnetic tape is smaller than the data buffer size or the sector size. Even if it is large, it can be accurately stored on the recording disk, and thus the data block can be accurately reproduced. As described above, even if the command from the host device is based on a data block for a magnetic tape, an unprecedented excellent recording disk control device capable of causing a recording disk device to behave as a magnetic tape device Can be provided.

[Brief description of the drawings]

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

FIG. 2 is a functional block diagram showing an example in which a configuration for processing relating to BOT is added to the configuration shown in FIG. 1;

FIG. 3 is a block diagram showing a configuration of hardware resources for executing the embodiment shown in FIG. 1;

4A and 4B show the contents of a control memory. FIG. 4A is an explanatory diagram showing an example of a pointer table, and FIG. 4B is an explanatory diagram showing an example of an address table.

FIG. 5 shows a logical tape image created in a physical data block of a sector of a magneto-optical disk medium, and FIG. 5A shows an example in which data of a continuous sector number is recorded in a data buffer memory. FIG. 5B is an explanatory diagram showing a data configuration in each sector.

FIG. 6 is a table showing correspondence between logical values of various flags and block boundaries in FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 host system 2 recording disk control device 3 recording disk device 3A recording disk 4 data buffer unit 5 host device transfer control unit 6 positioning control unit 7 control memory 8 control data management unit 9 running simulation unit 10 address management Means 23 Data buffer unit 24 Microprocessor unit 26 Address table 27 Pointer table

Claims (4)

(57) [Claims] A data buffer unit for temporarily storing data relating to data transfer between a host device and a recording disk device; and a data buffer unit for adding a block boundary to data received from the host device. A data transfer control unit for storing the data stored in the data buffer unit in the recording disk device and receiving the data stored in the recording disk device and storing the data in the data buffer unit Address control means for sequentially updating the address of data being transferred in the data buffer unit as a head position address in a control memory; and a block in the data buffer unit. Control data management means for sequentially updating control data recorded at the boundary in the control memory; Vs de position address on the magnetic tape from the upper apparatus as a head position for the magnetic tape
It accepts the positioning command and a traveling imitation means for controlling the data transfer between the recording disk apparatus and the data buffer unit based on the control data of the various commands and said control memory to said host device Transfer control unit for receiving from the higher-level device.
Data at the block boundary where the data block of the
With data block flag to add data block flag
Adding means for recording the data received from the host device
The sector boundaries in units of the sector size of the disk
Means for generating sector boundaries,
A sector number adding means for adding a sector number,
Data blocks received from the
Continuation flag to add a continuation flag to the sector boundary
Lag addition means and when the sector size is not exceeded
Addition of a termination flag to add a termination flag to the sector boundary
Recording disk controller characterized by comprising a means. 2. The apparatus according to claim 1, wherein the upper device transfer control unit sets a BOT on a block boundary assigned to a first sector of the recording disk.
A BOT flag adding means for adding a flag, and the running dummy production means reads out data in order from the first sector of the recording disk when receiving a rewind command from the host device, and stores the data in the data buffer section. A BOT search function for writing, and a BOT positioning function for outputting the address of a block boundary to which a BOT flag is added when the data is accumulated in the data buffer unit to the address management means as a head position address. 2. The recording disk control device according to claim 1, wherein: 3. A block number adding unit that, when receiving a data write command and data from the upper-level device, adds a continuous block number for each data block of the data to the block boundary. Means,
Tape mark flag adding means for adding a tape mark flag to the block boundary when a tape mark write command is received from the host device.
The recording disk control device according to claim 1 . 4. When the running simulating means receives a positioning command for a tape mark position, a block number, or the like from the higher-level device, it searches the head position address of the data buffer unit in a search direction according to the positioning command. A buffer position search function for reading the data from the sector following a sector number of a sector boundary to which the head position address belongs when the position is not searched by the buffer position search function. 4. The recording disk control device according to claim 3, further comprising a tape position search function for storing the data in a buffer unit.