JPH04221459A - Access method of large-capacity storage device - Google Patents

Abstract

PURPOSE:To reduce the burden of an OS and to increase the processing efficiency of a computer system by a method wherein a recording medium which has recorded a prescribed data block is indexed from a table and the medium is conveyed between a cell and a recording and replay part. CONSTITUTION:At the initial stage of a large-capacity storage device, a plurality of optical disk cartridges are stored in cells 34 to 35. At this time, the following are recorded in a table 31: the front block address of data blocks which have been mounted in the cells 34 to 35 so as to correspond to cell Nos. of the table 31 and which are situated inside respective recording media; and a final block address. A control means indexes, from the table 31, a medium which records a data block corresponding to an address designated by a write command or a read command sent out from a host device; it conveys the medium between the cell of the number designated by the table 31 and a recording and replay part 32; it records/replays a data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-capacity storage device that is used as an external storage device for a computer system and stores a plurality of recording media. The present invention relates to a method of accessing a mass storage device that allows access to write/read a single recording medium.

[0002] In recent years, as the amount of information in computer systems has increased, various automated large-capacity storage devices that do not require operator intervention have been provided as means for storing this information.

This large-capacity storage device is provided with a storage shelf that accommodates a large number of recording media such as magnetic tape cartridges and optical disk cartridges, and each storage medium is stored in a plurality of cells provided on the storage shelf that store the recording media. An accessor equipped with a mechanical hand takes out the necessary recording medium from the cell of the storage shelf, transports it to the recording/reproducing section, sets it, writes/reads data, and then writes/reads the data. When the process is completed, the recording medium is taken out from the recording/reproducing section again and transported to the cell of the storage shelf to be stored therein, and at the same time, according to instructions from the host device, the recording medium that is no longer needed is transported to the ejection port and the operator is made to take it out. It is configured as a kind of automatic warehouse in which the recording medium that the operator puts into the input slot is conveyed to a recording/reproducing section and set there, or conveyed to a cell and stored therein.

[0004] In this way, mass storage devices are created as a type of warehouse, and once the necessary recording media are stored, the accessor transports the recording media without the need for operator intervention. In order to control the transportation operation of this accessor, it is necessary to avoid placing a burden on the host device.

[0005]

2. Description of the Related Art FIG. 6 is a diagram illustrating an example of the configuration of a large-capacity storage device. FIG. 6 shows an example of a mass storage device using an optical disc cartridge as a recording medium, and is provided with storage shelves 15 to 17 to which a plurality of cells for storing optical disc cartridges 11 are attached, and the storage shelves 15 to 17 are designated. Optical disc cartridge 11 stored in the cell
is picked up and held by a picker 4 (mechanical hand) attached to the accessor 3, conveyed to a drive device 12 or 13 that writes/reads data, and sets the held optical disc cartridge 11 therein.

[0006] When data writing/reading is completed in the drive device 12 or 13, the drive device 1
The optical disk cartridge 11 is taken out from 2 or 13 and carried to a designated cell of storage shelves 15 to 17 to be stored therein.

Therefore, the accessor 3 moves in the direction of arrow AB, moves the picker 4 in the direction of arrow CD,
The picker 4 is positioned at the cell position of the designated storage shelf. Then, move the picker 4 in the direction of arrow E-F,
The optical disc cartridge 11 is taken out and stored.

Therefore, the accessor 3 is guided by the rails 1 and 2 and is moved in the direction of arrow AB by the screw 9 driven by the rotation of the motor 8, and by the belt 6 driven by the rotation of the motor 7. The picker 4 is moved in the direction of the arrow CD, and the picker 4 is moved in the direction of the arrow EF by a motor (not shown) provided on the picker support mechanism 5 fixed to the accessor 3.

Furthermore, it is necessary to set the optical disc cartridge 11 horizontally in the drive device 12 or 13, and the storage shelves 15 to 17 store the optical disc cartridge 11 vertically, so the main body of the picker 4 is It can be rotated by a shaft that is driven by a motor 10 and rotates.

[0010] Also, the drive device 12 or 13 can write/write.
When instructed to eject the optical disc cartridge 11 from which reading has been completed to the loading/unloading mechanism unit 14 which also serves as an input port and an output port, the picker 4 moves to the drive device 12 or 13.
The optical disc cartridge 11 taken out from the
It is set in the input/discharge mechanism section 14 that can be pulled out in the direction of.

Further, when instructed to transport the optical disc cartridge 11 set in the loading/unloading mechanism section 14 to a designated cell, the accessor 3 transports the optical disk cartridge 11 set in the loading/unloading mechanism section 14 by the picker 4. When the optical disc cartridge 11 is transported and the picker 4 is positioned at the designated cell position, the optical disc cartridge 11 is stored.

Note that the picker 4 in FIG. 6 is shown holding the optical disk cartridge 11. As shown in FIG. FIG. 7 is a block diagram illustrating an example of the prior art. The central processing unit 18 is an OS
Operates based on instructions from (operating system). Then, a move command for the accessor 3 is sent to the channel interface circuit 21 of the mass storage device 20 via the channel 19.

The parameters of this move command include 4
Two bytes indicate the source address of the accessor 3, and the next two bytes indicate the destination address of the accessor 3.

The processor 24 operates by reading a program stored in the control memory 25, and based on the move command sent by the central processing unit 18 via the channel interface circuit 21 and its parameters, the processor 24 executes the program via the accessor interface circuit 27. The movement source and destination of the accessor 3 are instructed to the control circuit 29 to instruct the movement of the accessor 3.

When the accessor control circuit 29 moves the picker 4 of the accessor 3 from the current position to the designated movement source address by driving each motor of the accessor 3 and picker 4 as described above, the optical disc is placed in the picker 4. The cartridge 11 is taken out.

[0016] Then, the accessor 3 is moved to the specified destination.
and moves the picker 4 to position the picker 4 at the specified address. That is, for example, if the source address is the cell number X and the destination is the drive device number Y, the picker 4 is moved according to the predetermined number of each cell provided in the storage shelves 15 to 17. The optical disc cartridge 11 is positioned in the cell with the designated number and taken out. If the drive device number Y is 12, the picker 4 is positioned in the drive device 12 and the optical disc cartridge 11 is set.

When the processor 24 is notified of the completion of the medium movement by the accessor control circuit 29 via the accessor interface circuit 27, it notifies the central processing unit 18 via the channel interface circuit 21 and the channel 19 of the completion of the command.

The drive interface circuit 26
The optical disc cartridge 11 set in the drive device 12 is rotated by instructing the drive control circuit 28 through the .

The drive control circuit 28 controls data writing/writing.
When it becomes ready to read, it interrupts the processor 24 via the drive interface circuit 26 and notifies it that it is ready.

Therefore, the processor 24 is the central processing unit 1
8 is notified by an interrupt that it has become ready. Therefore, the central processing unit 18 sends, for example, a read command to the processor 24.

The parameters of this read command specify how many blocks of data are to be read from which address on the optical disk cartridge 11, and the processor 24
instructs the drive control circuit 28 to position the head at the specified address.

The drive control circuit 28 is connected to the drive device 12.
to position the head at a specified address, that is, a specified sector of a specified track. When the data is read out, it is sent to the buffer memory 22 via the drive interface circuit 26.

The processor 24 controls the buffer memory 22 via the buffer control circuit 23, stores the read data, and then sends it to the channel 19 via the channel interface circuit 21.

When the specified number of blocks of data have been transferred, the central processing unit 18 is notified of the end of the read command. The central processing unit 18, which has been notified of the end of the read command, instructs the processor 24 to read the drive device 1.
A desmount command is sent to enable the ejection of the optical disc cartridge 11 set in No. 2.

Therefore, when the processor 24 instructs the drive control circuit 28 to stop the rotation of the optical disc cartridge 11 set in the drive device 12,
The central processing unit 18 is notified of the end of the desmount command.

The central processing unit 18 sends a move command, and the processor 24 controls the accessor control circuit 29 to drive the picker 4 of the accessor 3 based on the source and destination addresses specified by the parameters of the move command. When the device 12 is positioned and the optical disc cartridge 11 is taken out, it is transported to a designated cell position and stored.

When this movement is completed, the end of the move command is reported to the central processing unit 18. Further, when the central processing unit 18 is notified that it is in the ready state and sends a write command to the processor 24, for example, the parameters of the write command include from which address of the optical disk cartridge 11, The number of blocks of data to be written is specified, and the processor 24 instructs the drive control circuit 28 to position the head at the specified address.

When data is sent from the central processing unit 18 via the channel 19, the buffer control circuit 23 is instructed to store the data input via the channel interface circuit 21 in the buffer memory 22.

The drive control circuit 28 is connected to the drive device 12.
When the head is positioned at a specified address, that is, a specified sector of a specified track, the processor 24 is requested to send data, and the data is sent from the buffer memory 22 via the drive interface circuit 26. Data is sequentially written from designated sectors of an optical disk cartridge 11.

When the processor 24 has transferred the specified number of blocks of data, it notifies the central processing unit 18 of the end of the write command. The central processing unit 18, which has been notified of the end of the write command, sends a desmount command to the processor 24 to enable the removal of the optical disc cartridge 11 set in the drive device 12.

The same applies when the optical disc cartridge 11 is set in the drive device 13. FIG. 8 is a command processing sequence explaining the operation of FIG.

The central processing unit 18 sends a move command to the accessor 3 in step (1). The parameters of the command are cell X as the source and drive Y as the destination.

[0033] Upon receiving this move command, the processor 24 instructs the accessor 3 to move the optical disc cartridge in step (2). Then, after waiting for the end of the movement, the central processing unit 18 is notified of the end of the command.

[0034] In step (3), the processor 24
For example, the drive device 12 in which the optical disc cartridge is set is caused to rotate the optical disc cartridge,
Wait until it becomes ready. And step (4)
When the drive control circuit 28 notifies that the drive control circuit 28 is in the ready state, the central processing unit 18 is notified by an interrupt that the drive control circuit 28 has become ready.

In response to this notification, the central processing unit 18 sends out a read command through the locate/read command chain in step (5). That is, a read command is sent along with a parameter instructing how many blocks of data are to be read from which address on the recording medium.

In step (6), the processor 24 performs the operation of seeking and waiting for rotation of the drive device 12, and when the data transfer is completed, notifies the central processing unit 18 of the end of the read command.

Therefore, the central processing unit 18 executes step (
7), the processor 24 sends a desmount command, and in step (8), the processor 24 stops the rotation of the optical disc cartridge, and then sends the command to the central processing unit 1 to terminate the command.
8 will be notified.

The central processing unit 18 sends a move command to the accessor in step (9), and the processor 24 sends a move command to the accessor control circuit 29 in step (10).
It instructs the movement of the optical disk cartridge, waits for the completion of movement of the optical disk cartridge, and then notifies the central processing unit 18 of the end of the command.

[0039]

As mentioned above, conventionally, the central processing unit 18 is involved in transporting the recording medium as shown in steps (1), (7), and (9) in FIG. It needs to be supported by the OS that instructs the operation of the central processing unit 18.

[0040] In order to support the OS, it is necessary to manage what kind of data set is stored in the optical disk cartridge of which cell, and when there is a request for access to a data set, the optical disk in which the data set is stored is managed. Support is required for sending a move command to move an optical disk cartridge from a cell in which the cartridge is stored to a drive device, and sending a desmount command for the drive device.

[0041] Therefore, there is a problem that the load on the OS is large and the processing efficiency of the computer system is reduced. In view of such problems, the present invention provides the following information from the central processing unit 18:
The purpose is to reduce the burden on the OS by making it appear as a single optical disk device and only sending write commands or read commands, eliminating the need to send other commands.

[0042]

Means for Solving the Problems FIG. 1 is a block diagram illustrating the principle of the present invention. The mass storage device includes a plurality of cells 34 to 35 each storing a plurality of recording media, and a recording/reproducing section 3 that records/reproduces data on the recording medium.
2, 33, an accessor 3 that transports this recording medium, and the transport operation of this accessor 3 and recording/reproducing units 32, 33.
A control means 30 is provided for controlling the recording/reproducing operation of the recording/reproducing operation.

[0043] Then, each cell 34 corresponds to the cell number.
A table 31 is provided for recording the address of the first block and the address of the last block of a plurality of data blocks recorded on each recording medium stored in .

At the initial stage of the mass storage device, recording media are stored in each of the cells 34 to 35. At this time, the storage media mounted in each of the cells 34 to 35 are stored in accordance with the cell numbers in the table 31. The first block address and the last block address of the data block are recorded in this table 31, respectively.

The control means 30 indexes from this table 31 the recording medium on which the data block is recorded corresponding to the address specified by the write command or read command sent by the host device, and uses the cell number specified by this table 31. A recording medium is transported between a cell, for example, the cell 34, and the recording/reproducing section 32, and data is recorded/reproduced.

Further, the control means 30 indexes the recording medium on which the data block is recorded from the table 31 corresponding to the start address of the data block specified by the write command or read command sent by the host device, and uses this table 31 A cell with the cell number specified by and one recording/playback section,
For example, the recording medium is transported to and from the recording/reproducing section 32 to record/reproduce data, and the recording medium set in the recording/reproducing section 32 is transferred to another recording/reproducing section, for example, the recording/reproducing section 33. A recording medium on which data is to be recorded/reproduced next to the medium is indexed from this table 31, transported and set in advance, and by alternately switching the plurality of recording/reproducing units 32 and 33, a plurality of recording media can be recorded. to record/reproduce data continuously.

[0047]

[Operation] With the above configuration, the host device can write/read data by simply sending a write command or read command, regardless of transport of the recording medium, reducing the burden on the OS. . Therefore, the processing efficiency of the computer system can be improved.

[0048]

Embodiment FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention, and FIG. 3 is a diagram illustrating an example of a table.

FIG. 2 shows a table 31 added to FIG. 7, and the same reference numerals as in FIG. 7 indicate the same functions. Initially, the processor 24 uses the accessor 3 as explained in FIG.
After storing the optical disc cartridges loaded into the loading/unloading mechanism section 14 shown in FIG. Writes the start address and end address of the data block recorded for each cartridge.

As shown in FIG. 3, the table 31 has a column for recording the cell address, a column for recording the first block address of each optical disk cartridge, and a column for recording the last block address corresponding to the cell address. It is provided.

The mass storage device shown in FIG. 6 has 32 cells that can be used by the user. Therefore, the cell address column of the table shown in FIG. 3 contains cell numbers from "0" to "31". It is assumed that all cells have optical disk cartridges stored therein. The number of data blocks stored in each optical disc cartridge is usually the same, but it may be different for each optical disc cartridge.

[0052] If the address of the first block of the data block of the optical disk cartridge stored in the cell with cell number "0" is 0 and the address of the last block is A, the data will be stored in the next cell with cell number "1". The first block address of the optical disc cartridge thus created is A+1, and the last block address is B.

Further, the address of the first block of the data block of the optical disk cartridge stored in the next cell with cell number "2" is B+1, and the address of the last block is C. The first block address of the optical disk cartridge stored in the cell with cell number "3" is C+1, and the last block address is D.

In this way, the first block address of the optical disc cartridge stored in the cell with cell number "31" is X+1 and the last block address is Y. In the above example, the first block address of each optical disk cartridge increases in order of cell number, but it goes without saying that this order may be different.

As explained in FIG. 7, the central processing unit 18 sends, for example, a read command to the processor 24 via the channel 19 and the channel interface circuit 21. When the processor 24 receives the address M of the data block to start reading and the number of blocks 4 from the parameters accompanying the read command, it refers to the table 31 and selects the optical disk cartridge to be transported.

That is, assuming that B<M<(C+1), the data block at address M exists in the optical disk cartridge stored in the cell with cell number "2", so the processor 24 uses the accessor control circuit 29 , an instruction is given to transport the optical disc cartridge from the cell with cell number "2" to the drive device 12.

Therefore, when the accessor control circuit 29 positions the picker 4 of the accessor 3 at the cell with cell number "2" and takes out the optical disc cartridge,
The drive device 12 carries it and sets it.

When the optical disc cartridge is set in the drive device 12, the processor 24 instructs the drive control circuit 28 to rotate the optical disc cartridge, and when there is an interrupt notifying that the optical disc cartridge is ready,
Calculate address m within the optical disc cartridge.

That is, m=M-(B+1), which is the address of the target data block. Therefore,
The processor 24 sends this address to the drive control circuit 2.
8, the head of the drive device 12 is positioned at address m, and data is read.

When the processor 24 sends the designated four blocks of data to the channel 19 via the buffer memory 22, it sends a desmount command to the drive control circuit 28 to stop the rotation of the drive device 12. Then, the drive device 1
2 is instructed to be transported to the cell with cell number "2".

When the conveyance is completed, the central processing unit 18 is notified of the completion of the read command via the channel interface circuit 21 and the channel 19. If (C+1
)≦(M+4), the processor 24 causes the cell with cell number "2" to transport the optical disc cartridge, and then causes the cell with cell number "3" to transport the optical disc cartridge stored in the drive device. Set it to 13.

When data reading in the drive device 12 is completed, the head of the drive device 13 is then positioned at the leading address of the optical disc cartridge, and data is read from data block C+1.

FIG. 4 is a command processing sequence explaining the operation of FIG. The central processing unit 18 performs step (1
1) For the processor 24, at the block address M,
Send a read command specifying the number of blocks 4 as a parameter.

When the processor 24 receives the read command in step (12), it receives the block address M and the block number 4 from the parameters. Then, in step (13), refer to table 31 and select cell number "2".
Select the optical disc cartridge in . Then, in step (14), the accessor control circuit 29 is instructed to carry it to the drive device 12.

[0065] In step (15), the processor 24 completes transportation of the optical disc cartridge and transfers the drive device 1 to the drive device 1.
2 becomes ready, and the drive control circuit 28
When the ready state interrupt is raised, the address within the optical disk cartridge is calculated. Then, in step (16), the head of the drive device 12 is positioned at the data block M, and the data block is read out.

Then, in step (17), four blocks of data are transferred from the drive device 12 to the central processing unit 18, and in step (18), a desmount command is sent to the drive control circuit 28, and the optical disc cartridge in the drive device 12 is stop the rotation.

[0067] The processor 24 then performs step (19).
) instructs the accessor control circuit 29 to transport the optical disc cartridge from the drive device 12 to the cell with cell number "2".

When the transportation is completed in step (20), the central processing unit is notified of the end of the read command. FIG. 5 is a diagram illustrating the difference in processing time between the case of one drive device and the case of two drive devices.

FIG. 5A shows the processing time when there is only one drive device, and each of the processing times (21) to (31) is required, and the required time is the total time. However, (2
1) is the time for receiving parameters and calculating cell numbers, and assumes that the data blocks to be processed span cell number "2" and cell number "3".

(22) is the time it takes to move the recording medium with cell number "2" to the drive device 12 (23) is the time it takes for the drive device 12 to become ready (24) is the time it takes to position the head, wait for rotation, and store the data. The total transfer time (25) is the time to take out the recording medium from the drive device 12 (26) is the time to return the recording medium from the drive device 12 to cell number "2" (27) is the time to take out the recording medium with cell number "3" from the drive. The time to move to the device 12 (28) is the time until the drive device 12 becomes ready (29) is the total time for positioning the head, waiting for rotation, and data transfer (30) is the time to take out the recording medium from the drive device 12. (31) is the time required to return the recording medium from the drive device 12 to cell number "3". However, (27)' to (31
)', the drive device 12 becomes 13.

FIG. 5(B) shows the processing time when there are two drive devices, and shows the processing time of (23) to (26) and (27).
)', the processing of (28)' and a part of the processing of (29)',
That is, the head positioning and rotation waiting processing can be performed in parallel, and the processing time is thus shorter than in the case of FIG. 5A.

[0072]

As explained above, the present invention allows a large-capacity storage device to correspond to one optical disk device, so that the central processing unit only needs to send a read command or a write command, and the burden on the OS is reduced. Therefore, the processing efficiency of the computer system can be improved.

Furthermore, if there are a plurality of drive devices, processing efficiency can be further improved.

[Brief explanation of the drawing]

[Figure 1] Block diagram explaining the principle of the present invention

[Figure 2
] Block diagram of a circuit showing one embodiment of the present invention

[Figure 3
] Diagram explaining an example of a table

[Figure 4] Command processing sequence explaining the operation in Figure 2

[Figure 5] Diagram explaining the difference in processing time between one drive device and two drive devices

[Figure 6] Diagram illustrating a configuration example of a mass storage device

[Figure 7] Block diagram illustrating an example of conventional technology

[Figure 8]
Command processing sequence explaining the operation in Figure 7

[Explanation of symbols]

1, 2 Rail 3 Accessor 4 Picker 5 Picker support mechanism 6 Belt 7, 8, 10 Motor 9 Screw 11 Optical disk cartridge 12, 13 Drive device 14 Insertion/ejection mechanism section 15, 16, 17 Storage shelf 18 Central processing unit 19 Channel 20 Large Capacity storage device 21 Channel interface circuit 22 Buffer memory 23 Buffer control circuit 24 Processor 25 Control memory 26 Drive interface circuit 27 Accessor interface circuit 28 Drive control circuit 29 Accessor control circuit 30 Control means 31 Tables 32, 33 Recording/reproducing section 34, 35 Cell

Claims (2)

[Claims] Claim 1: A plurality of cells (34) (35) each storing a plurality of recording media, a recording/reproducing unit (32) for recording/reproducing data on the recording medium, and transporting the recording medium. Accessor (3) and the accessor (3)
In the mass storage device, each cell (34) to (
A table (31) is provided for recording the address of the first block and the address of the last block of a plurality of data blocks respectively recorded in each recording medium stored in the recording medium (35), and the recording medium is stored in each cell (34). ~ (35), each cell (
34) After recording the first block address and last block address of the data blocks in each recording medium implemented in (35) in the table (31), a write command or a read command is sent by the host device. A recording medium for recording a data block corresponding to the address specified by is indexed from the table (31), and the table (31) is indexed.
31) and the cell with the cell number specified by the recording/reproducing unit (32).
) to record/record data.
A method for accessing a mass storage device characterized by causing playback. 2. A plurality of cells (34) to (35) each storing a plurality of recording media, and a plurality of recording/reproducing units (32) (33) for recording/reproducing data to/from the recording medium.
, an accessor (3) that transports the recording medium, and a transport operation of the accessor (3) and the recording/reproducing unit (32).
(33) Control means (30) for controlling the recording/reproducing operation of
), the address of the first block of a plurality of data blocks recorded on each recording medium stored in each cell (34) to (35), corresponding to the cell number. , the address of the final block, and a table (31) for recording the address of the last block.
) to (35), the first block address of the data block in each recording medium mounted in each cell (34) to (35), corresponding to the cell number of the table (31); The final block address is in the table (31)
After recording each data block in the table (31), the recording medium on which the data block is to be recorded is indexed from the table (31) in accordance with the start address of the data block specified by the write command or read command sent by the host device. )
A recording medium is transported between a cell with a cell number specified by a cell and one recording/reproducing unit, and data is recorded/reproduced, and data is subsequently recorded/reproduced on the recording medium. Other recording media are indexed from the table (31), transported and set in advance in other recording/reproducing sections, and by alternately switching the plurality of recording/reproducing sections (32) and (33). 1. A method for accessing a large-capacity storage device, characterized in that data is continuously recorded/reproduced on a recording medium.