JPH03183067A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To optimumize the move of a magnetic head when an instruction is executed by simultaneously executing the plural read / write instructions. CONSTITUTION:When the prescribed number of read / write instructions are held in a memory 4 or after the lapse of prescribed time, a control part 6 rearranges the read / write instructions in order according to cylinder sector numbers and the instructions are executed according to the order. Therefore, a magnetic head 1 is moved according to the order for the cylinder number of a magnetic disk 3 and is not moved back and forth repeatedly within an overlapped range. The read instruction is executed and the read data are held in a memory 5. Then, the control part 6 outputs the data corresponding to the read instructions while rearranging the data in the order of the original read instructions. Accordingly, the data can be received according to the order of the read instructions.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to optimize the movement of the magnetic head when executing read/write commands with respect to a magnetic disk device capable of high-speed operation. In a magnetic disk device that writes data to or reads data from a magnetic disk, the first
a second memory that holds data read by executing a read instruction; and when the number of read/write instructions held in the first memory reaches a predetermined number or a predetermined time elapses, the first Sort the read/write instructions held in memory in the order according to cylinder and sector numbers,
Execute the read/write command, hold the data read by the execution of the read command in the second memory, and rearrange the data held in the second memory in the original order of the read command. The controller is configured to include a control section for outputting data.

[Industrial application field]

The present invention relates to a magnetic disk device capable of high-speed operation.

As the speed of information processing in computer systems increases, magnetic disk devices such as file devices are also required to operate at higher speeds.

[Conventional technology]

Magnetic disk drives have been put into practical use in various configurations ranging from small to large, and attempts are being made to increase the capacity by increasing the number of magnetic disks mounted or by improving the recording density.

To such a magnetic disk device, a read/write command, as well as a cylinder number and a sector number, are given from a host computer, etc., and the magnetic head is positioned at the cylinder position of the magnetic disk corresponding to the cylinder number. Data is read from the sector specified by the sector number, and in the case of a write command, data is written to the sector specified by the sector number. Then, the magnetic head is moved to the cylinder position according to the next read/write command.

[Problem that the invention seeks to solve]

As mentioned above, in conventional magnetic disk drives,
Given read/write commands are executed sequentially, and cylinder numbers according to read/write commands are generally random, so the magnetic head may repeatedly move back and forth over overlapping ranges. In extreme cases,
Since the magnetic head sometimes moves back and forth between the inner cylinder and the outer cylinder, it has been difficult to improve the execution speed of read/write commands due to the time required for the movement of the magnetic head.

An object of the present invention is to optimize the movement of a magnetic head when executing a read/write command.

[Means for Solving the Problems] A magnetic disk device of the present invention executes a plurality of read/write commands at once, and will be described with reference to FIG.

A magnetic disk device that positions a magnetic head 1 using a drive unit 2 such as a voice coil motor to write data to or read data from a magnetic disk 3 holds a plurality of read/write commands from an external device such as a host computer. a first memory 4 that stores data read by executing a read command; a second memory 5 that stores data read by executing a read command;
When the number of read/write commands held in the first memory 4 reaches a predetermined number or a predetermined period of time has elapsed, the read/write commands held in the first memory 4 are rearranged in the order according to the cylinder sector number, and the read/write commands are read/written.・Execute the write command, hold the data read by executing the read command in the second memory 5, rearrange the data held in the second memory 5 according to the original order of the read command, and output it. The control unit 6 is also provided with a control unit 6.

[Effect]

When a predetermined number of read/write commands are held in the first memory 4 or when a predetermined period of time has elapsed, the control unit 6 rearranges the read/write commands in the order according to the cylinder sector number, execute instructions according to the instructions. Therefore, the magnetic head 1 is moved in accordance with the order of the cylinder numbers of the magnetic disk 3, and does not repeatedly move back and forth through overlapping ranges.

Further, the data read by executing the read command is held in the second memory 5, and the control unit 6 rearranges the data corresponding to the read command in the order of the original read command and outputs the rearranged data. Therefore, data can be received and received externally in accordance with the order of read commands.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention, in which 11 is a magnetic head, 12 is a drive unit including a voice coil motor, 13 is a magnetic disk, 14 is a spindle motor, 15
16 is a rotation control circuit, 16 is a positioning control circuit, 17 is a read/write control circuit, 18 is an internal bus, 19 is a magnetic disk control circuit, 20 is a microprocessor (MPU),
21 is a first memory area 21a and a second memory area 21
22 is an interface circuit, 23 is a memory consisting of
is the host computer.

The configuration including the microprocessor 20 and the magnetic disk control circuit 19 corresponds to the control section 6 in FIG.
The first memory area 21a and the second memory area 21b correspond to the first memory 4 and the second memory 5 in FIG.

Also, although the illustration shows a case where there is only one magnetic day and Sufu 13,
A configuration in which a plurality of sheets are attached to a spindle is common, and a spindle motor 14 is controlled by a rotation control circuit 15.
rotated at a constant speed.

The magnetic head 11 is generally arranged on both sides of the magnetic disk 130, and is positioned at a designated cylinder position on the magnetic disk 13 by a drive unit 12 controlled by a positioning control circuit 16. The read/write control circuit 17 also includes a modulation section that modulates data and applies it to the magnetic head 11, and a demodulation section that demodulates successive signals and converts them into data.

Furthermore, the management of the cylinder number and sector number of the magnetic disk 13 as the physical address of the storage area is normally performed on the host computer 23 side, but it may be configured to be managed by the microprocessor 20 or the like on the magnetic disk device side. You can also do it.

When a read/write command is given from the host computer 23, the data is stored in the first memory area 21a of the memory 21 under the control of the microprocessor 20. This first
When a predetermined number of read/write commands are accumulated in the memory area 21a, or when there is no next read/write command after a predetermined period of time, the order of cylinder numbers and the same cylinder number are determined by the control of the microprocessor 20. In this case, read/write instructions are rearranged according to the order of sector numbers. In this case, the read/write commands are equivalently rearranged by manipulating the stored addresses.

The rearranged read/write commands are executed under the control of the magnetic disk control circuit 19. By applying a control signal according to the cylinder number to the positioning control circuit 16, the drive unit 12 moves the magnetic head 11 to the magnetic disk. It is positioned at cylinder number position 13. Further, in the case of a read command, the read/write control circuit 17 demodulates the successive signals from the magnetic head 11 and transfers the signals to the magnetic disk control circuit 19 via the internal bus 18, and the transferred data is sent to the microprocessor 20. is stored in the second memory area 21b of the memory 21 under the control of the memory 21. In the case of a write command, data is modulated, applied to the magnetic head 11, and written to the magnetic disk 13.

A series of read/write instructions are executed, and the data read out by executing the write instructions among them and stored in the second memory area 21b is rearranged according to the order of the original write instructions under the control of the microprocessor 20. It will be done.

The data is then sent to the host computer 23 via the interface circuit 22.

FIG. 3 is a flowchart of an embodiment of the present invention, in which it is determined from the state of waiting for command reception (■) whether there is an instruction sending request from the host computer 23, and if there is an instruction sending request, the read/write command is accepted; It is determined whether or not there is space in the first memory (first memory area 21b). If there is space, the instruction is stored. Alternatively, it is possible to determine whether a predetermined number of instructions are stored in the first memory, and if the predetermined number of instructions are not stored, the instructions can be stored.

If there is no command sending request, the system enters a state of waiting for command reception and determines whether a predetermined time has elapsed.When the predetermined time has elapsed, determines whether there is an instruction stored in the first memory. However, if there is no stored instruction, the system enters the state of waiting for command reception.

Also, if there is an instruction stored in the first memory, if an instruction is accepted and there is no more space in the first memory, or if a predetermined number of instructions are stored in the first memory as described above. Then, the read/write execution is notified to external devices such as the host computer 23. That is, it notifies the outside that the magnetic disk device is in a busy state.

Then, the read/write commands are rearranged according to the order of cylinder numbers and sector numbers, and the commands are executed [phase]. Then, it is determined whether or not a read command is included (1). If there is only a write command and no read command is included, the command is notified to the outside that the command can be received [phase], and the state is set to (3) waiting for command reception. In addition, if a read command is included, successive data is stored in the second memory (second memory area 21b).
) and rearrange the subsequent data according to the order of the original read command. After this sorting is completed, it is determined whether or not the data can be sent.■ If it is possible to send the data, the data is sent to the outside such as the host computer 23.■, It is notified to the outside that the command can be received.■ It waits for the command to be received. The state will be as follows.

As mentioned above, the magnetic head in the magnetic disk device has a plurality of magnetic heads 11 corresponding to the number of magnetic disks 13, for example, head numbers l to 5.
An example of the execution of a read/write command when the apparatus has a magnetic head with a magnetic disk having cylinder numbers 100 to 1000 will be described with reference to FIG.

The read command R and write command W are shown in [1] in FIG.
When the commands are given in the order shown in FIG.
00 → 700 → 500 → 900 → 200 → 1000
→600→300→800→200, etc., and will be randomly moved to the position of the cylinder number.

Therefore, such read/write commands R/W are stored in the first memory area 21a, and when a predetermined number of 10 instructions has passed, or when a predetermined time has elapsed, they are rearranged according to the order of cylinder numbers. , if the cylinder numbers are the same, they are sorted according to the order of sector numbers. For example, the instruction number 5.1° has the same cylinder number 200, but the sector number is 17.11. Since the sector number of instruction number 5 is large, it is rearranged in the order of instruction number 10.5. . Therefore, the read/write commands R/W of command numbers 1 to 10 are as shown in [2]! ,10,5
, 8, 3, 7, 2, 9, 4.6.

The reordering of the read/write commands R/W as described in 2 above can be processed at high speed by, for example, providing a conversion table for the addresses of the first memory area 21a and performing the reordering on this conversion table. I can do it.

Then, as the instruction execution order, (a) cylinder number 1
The magnetic head 11 is moved from 00 to 1000, and the command numbers are 1 → 10 → 5 → 8 → 3 → 7 → 2 → 9.
→ Perform in the order of 4 → 6, or (b) cylinder number 5
Assuming that the magnetic head 11 is located at cylinder number 500, the instruction number is 3→8→
The order is 5→10→1→7→2→9→4→6. Alternatively, the order of execution of the instructions in (a) can be reversed, and similarly, the order of execution of the instructions from cylinder number 500 to cylinder number 1000 can be executed first, contrary to the order of execution of instructions in (b). It is possible.

FIG. 5 shows the direction of movement of the magnetic head according to the above-mentioned command execution order, where al indicates the case where commands are executed in the order of cylinder numbers from outside to inside, and a2 indicates the direction in the opposite direction. Indicates when instructions are executed in order.

Also, b1 indicates a case where commands are executed in the order of cylinder numbers going outward from the middle cylinder number position, and after returning to the middle cylinder number position, commands are executed in the order of cylinder numbers going inward. . In this case, after the magnetic head is first moved to the position of the outer cylinder number, the instruction execution order may be as shown in al. Further, b2 indicates a case where instructions are executed in the opposite order to bl.

It is also possible to determine the instruction execution order based on the current position of the magnetic head. For example, control can be performed so that an execution order similar to either bl or b2 is selected depending on whether the cylinder number is located at the outer cylinder number or the inner cylinder number of the magnetic disk.

If a read command R is included, the successive data is stored in the second memory area 21b, and when the commands are executed in order from cylinder number 100, the successive data is rearranged. Instruction number 1.10, 8, 3, 2
．． According to the read command R of 9, as shown in [3], the RD
I, RDIO.

RD8. RD3. RD2. They are stored in the second memory area 21b in the order indicated by RD9.

This is to rearrange the successive data stored in the second memory area 21b in the original order of the read command R. As a result of this rearrangement, as shown in [4] on the right side, the RDI, RD
2. RD3. RD8. They become RD9 and RDIO. Thereby, by sequentially sending out the successive data, it is possible to send out the successive data in the order according to the given read command.

In this case, it is possible to rearrange the successive data, but since it would take a considerable amount of time to replace a large amount of data in the memory, it is possible to rearrange the successive data, but since it would take a considerable amount of time to rearrange a large amount of data in the memory, it is possible to rearrange the successive data. By providing a conversion table for the addresses of each successive data stored in the second memory area 21b and performing rearrangement on this conversion table, high-speed rearrangement ζ' becomes possible.

For example, the read/write command R/ shown in [1] in FIG.
Assuming that W is given and the magnetic head 11 is located at cylinder number 500, a given read/write command R
In the conventional example where instructions are executed according to the order of /W,
The moving distance of the magnetic head 11 is 4900 cylinders, but according to the above-described embodiment of the present invention, the moving distance is reduced to 300 cylinders, and the moving distance of the magnetic head 11 can be significantly reduced. Therefore, after accumulating multiple read/write instructions R/W, it is necessary to rearrange the instructions.
Since the sorting process can be performed at a high speed compared to the moving speed of the magnetic head 11, on average the read/write command R
/W can be executed faster.

〔Effect of the invention〕

As explained above, the present invention stores read/write commands in the first memory 4, and when a predetermined number of read/write commands have been stored or a predetermined time has elapsed under the control of the control unit 6, the cylinder・Read/write commands are executed by rearranging sectors according to the order of sector numbers, which eliminates the need to repeatedly move the magnetic head l back and forth within overlapping ranges, and instead moves read/write commands according to the order of cylinder numbers. Since the command is executed, read/write commands can be executed at high speed.

Further, the data successively output by executing the rearranged read commands is stored in the second memory 5, rearranged and outputted according to the original order of the read commands, and the magnetic head l
By optimizing the movement of the data, even if successive data is obtained in an order different from the order of the read command, it can be returned to the original order of the read command and sent to the external device.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the invention, Fig. 3 is a flowchart of an embodiment of the invention, and Fig. 4 is a read/write instruction of an embodiment of the invention. FIG. 5 is an explanatory diagram of the movement direction of the magnetic head. 1 is a magnetic head, 2 is a drive unit, 3 is a magnetic disk, 4,
5 is a first and second memory, and 6 is a control unit.

Claims (1)

[Claims] In a magnetic disk device that positions a magnetic head (1) by a drive unit (2) to write or read data on a magnetic disk (3), a plurality of external read/write commands are provided. A first memory (4) that holds data, and a second memory (4) that holds data read by executing a read command.
a memory (5), and when the number of read/write commands held in the first memory (4) reaches a predetermined number or a predetermined period of time has elapsed, the read/write commands held in the first memory (4) are read/write. The instructions are rearranged in the order according to cylinder/sector numbers, the read/write instructions are executed, and the data read by the execution of the read instructions is held in the second memory (5), and the second A magnetic disk device comprising: a control unit (6) that rearranges data held in a memory (5) in the original order of a read command and outputs the rearranged data.