JPH02240880A - Disk device - Google Patents

Abstract

PURPOSE:To attain the efficient operation of a device and a system by providing a storage means storing the operating state at every cylinder and revising the head position when access is not inputted for a prescribed time. CONSTITUTION:A statistic information storage circuit 12 stores statistic information such as access number, frequency and operating state at every cylinder of a positioned disk medium. A timer circuit 16 counts the time without access from a host device and when the time exceeds the prescribed time, a timer signal 108 is issued to a control circuit 11 to be informed. The circuit 11 outputs a signal 105 to a selection circuit 13 to select a cylinder data 101 and outputs an execution signal 107 to a positioning control circuit 15 in the next timing to revise the head position. In response to the stored operating state, since the head position on the disk medium is revised, it is not required to move the head at each access, thereby attaining efficient operation.

Description

TECHNICAL FIELD The present invention relates to a disk device, and more particularly to a control mechanism for a drive controller that performs positioning control in a magnetic disk device.

Prior Art A conventional magnetic disk device will be explained using a connection configuration of a magnetic disk device in a computer system shown in FIG.

Generally, magnetic disk device 6-1 (i-1, 2゜...
... n) is connected to the computer system 3,
A central processing unit (CPU) 4 and a magnetic disk drive controller (DKC) (hereinafter referred to as controller) connected to the central processing unit 4 via an interface 121.
5 and a magnetic disk device 6-1 connected to the controller 5 via an interface 122.

Each magnetic disk device 6-1 also has a disk drive unit (D
K) 62-1 to 65-1 and disk drive unit 62-i to
A drive unit controller (DDC) for controlling 65-1.
) 61-1, and are connected to each other via an internal interface 123-1.

This central processing unit 4 specifies the magnetic disk device 6-1 to the controller 5 during a read operation to read data recorded on the magnetic disk device 6-1 or a write operation to record new data. Address information for performing the read operation or write operation is sent via the interface 121.

When the controller 5 receives the address information from the central processing unit 4, it sends detailed address information to the drive unit controller 61-2 of the magnetic disk device 6-i via the interface 122.

This detailed address information includes the number of the magnetic disk device 6-1 and the disk drives 62-1 to 65- connected to it.
It is made up of information indicating the number I, the cylinder address and head address of the disk drive units 62-1 to 65-2, and the sector position.

Drive unit controller 61-1 of magnetic disk device 6-i
In the address information from the controller 5, since the number of the magnetic disk device 6-1 corresponds to the number of the own device,
The address information excluding the device number from the address information is sent to the disk drive units 62-1 to 65-2.

In the disk drive units 62-1 to 65-1, when the number of the disk drive unit 62-1 to 65-i corresponds to its own number among this address information, the cylinder address in the sent address information is used. The head is positioned, the head is selected, and the search for the sector position begins.

When this sector position search is completed, the drive unit controller 61-2 issues an attention to the controller 5 to notify the completion.

Upon receiving the attention from the drive unit controller 61-1, the controller 5 starts reading or writing data to the magnetic disk device 6-1.

Generally, the access time from when the disk drives 62-I to 65-1 receive address information from the controller 5 to positioning at the position indicated by the address information is much longer than the processing time of the controller 5. After the controller 5 sends address information to the disk drives 62-1 to 65-1, the disk drives 62-1 to 65-1
If you wait to start the next process until 65-1 finishes positioning, the efficiency of the entire system will decrease, and
The operating rate of the magnetic disk device 6-1 will decrease.

Therefore, the controller 5 has the disk drive section 62-1.
When the address information is sent to ~65-■, the disk drive units 62-I to 65-■ are sequentially equipped without waiting until the positioning operation is completed.
Select I to 65-1 and drive the disk drives 62-1 to 62-6.
5-1, and instructs the disk drive units 62-1 to 65-1, which have completed the positioning operation and sent the attention, to perform a read operation or a write operation. It is controlled to be sent.

Therefore, the magnetic disk device 6- which is in the online state
[ needs to be in an instruction standby state in order to receive an instruction from the controller 5 regardless of whether there is an access from the controller 5 or not.

In such a conventional magnetic disk device 6-1, when the cylinder address of the address information sent from the host device during a data read or write operation is different from the currently positioned cylinder address, the address information is To perform positioning operation to the cylinder address,
Since time is required to perform a positioning operation before a data read or write operation is performed, a data read or write operation cannot be performed immediately based on address information sent from a host device.

This means that even if the host device is not monopolized by a single device and controls sending commands sequentially to multiple devices,
If the number of magnetic disk devices 6-1 is small or if the number of host devices is large, a lot of waiting time will occur.

Therefore, in the conventional magnetic disk device 6-1, there is a waiting time for performing a positioning operation, so there is a drawback that the system and the magnetic disk device 6-1 cannot be operated efficiently.

OBJECTS OF THE INVENTION The present invention has been made to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide a disk device that allows efficient operation of systems and devices.

Structure of the Invention The disk device according to the present invention includes a storage means for storing the usage status of each cylinder of the disk medium, and a storage means that stores the usage status for each cylinder of the disk medium, and when no access from the host device is input for a predetermined period of time.
The apparatus is characterized by comprising a changing means for changing the position of the head on the disk medium according to the usage status stored in the storage means.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, a control circuit 11 of a magnetic disk device 1 decodes a command 100 sent from a host device (not shown) and instructs detailed operations to various parts within the device.

The statistical information storage circuit 12 stores statistical information such as the number of accesses and the access frequency for each positioned cylinder address. That is, the statistical information storage circuit 12 takes in cylinder data lots from the host device using a positioning information write signal (hereinafter referred to as a write signal) 102 from the control circuit 11, and receives a positioning information read signal (hereinafter referred to as a read signal) from the control circuit 11. ) 103 sends the cylinder data 104 to the selection circuit 13.

The selection circuit 13 selects one of the cylinder data 101 of the host device and the cylinder data 104 from the statistical information storage circuit 12 in response to a cylinder data selection signal (hereinafter referred to as selection signal) 105 from the control circuit 11; The selected data is sent to the cylinder storage circuit 14 as cylinder data 109.

When the cylinder storage circuit 14 receives the cylinder data 109 sent from the selection circuit 13, it holds the data using a cylinder data holding signal (hereinafter referred to as a holding signal) 10B from the control circuit 11, and also sends the data to the positioning control circuit 15. The cylinder data 110 is sent to the cylinder data 110.

When the positioning control circuit 15 receives the positioning execution signal (hereinafter referred to as execution signal) 107 from the control circuit 11 and the cylinder data 110 from the cylinder storage circuit 14, it performs a positioning control operation on the head disk assembly (HDA) 17. Positioning control signal [11
and performs positioning at the target cylinder address.

The timer circuit 16 measures the time when there is no access from the host device, and when the time exceeds a certain threshold, the control circuit 1
1, the control circuit 11 outputs a timer signal 10B to indicate that the time without access from the host device exceeds the threshold.
Notify.

The head disk assembly 17 includes a magnetic disk medium (not shown) on which data is recorded, a magnetic head (not shown) that reads and writes data, an arm (not shown) that supports a plurality of magnetic heads, and a magnetic head. This is a mechanical unit that integrates a magnetic circuit (not shown) for moving the magnetic disk to a predetermined position, a motor (not shown) for rotating the magnetic disk medium, etc.

There are two states in the control circuit 11: a state in which it operates under control from a host device and a state in which it operates in accordance with statistical information stored in the statistical information storage circuit 12.

That is, when the control circuit 11 is in a state where it operates under the control from the higher-level device, when the control circuit 11 receives the positioning command 100 sent from the higher-level device, it outputs the write signal 1.
02 is output to the statistical information storage circuit 12, and the cylinder data 101 sent simultaneously with the positioning command 100 is taken into the statistical information storage circuit 12.

At the same time, the control circuit 11 sends a selection signal 105 to the selection circuit 13.
is outputted to cause the selection circuit 13 to select the cylinder data lot from the host device, and then a holding signal 10B is outputted to the cylinder storage circuit 14 to cause the cylinder data 109 from the selection circuit 13 to be held.

Further, the control circuit 11 outputs an execution signal 107 for causing the positioning control circuit 15 to perform a positioning operation at the next timing. As a result, the head disk assembly 17 performs a positioning operation based on the cylinder data 101 sent from the host device.

When the control circuit 11 is in a state in which it operates based on the statistical information stored in the statistical information storage circuit 12, the control circuit 11 checks the state of the timer signal 108 from the timer circuit 16 when there is no access from the host device, and determines whether there is an access. When it is detected that the time exceeds the threshold, the statistical information storage circuit 12
Read signal 1 to read cylinder data 104 from
03 is output to the statistical information storage circuit 12.

The control circuit 11 also sends a selection signal 1 to the selection circuit 13.
05 and causes the selection circuit 13 to select the cylinder data 104 from the statistical information storage circuit 12.

After that, the control circuit 11 outputs the holding signal LH to the cylinder storage circuit 14, and the selection circuit 1
10g of cylinder data from 3 is retained.

The control circuit 11 activates the positioning control circuit 15 at the next timing.
Execution signal 107 for performing positioning operation on
Output. As a result, the head disk assembly 17 performs a positioning operation based on the statistical information stored in the statistical information storage circuit 12.

FIG. 2 is a diagram showing positioning control based on the number of accesses according to an embodiment of the present invention, and FIG. 3 is a flowchart showing the storage operation of the number of accesses in the statistical information storage circuit 12 of FIG.

Positioning control based on the number of accesses according to an embodiment of the present invention will be explained using FIGS. 1 to 3.

In the magnetic disk device 1, access is made to each of the cylinders 21 to 24 from the outermost cylinder 21 to the innermost cylinder 24 in which data is recorded among the outer shape 20 to the inner shape 25 of the magnetic disk medium 2. The number of times is stored in the statistical information storage circuit 12.

That is, when an access command is input from the host device (step 31 in FIG. 3), the statistical information storage circuit 12 converts the cylinder address from the host device into a memory address (step 32 in FIG. 3). The contents stored in the memory (not shown) of the statistical information storage circuit 12 are read (step 33 in FIG. 3).

Next, the statistical information storage circuit 12 stores the contents read from the memory, that is, the number of accesses of the cylinders 21 to 24
Then, "1" is added to (step 34 in FIG. 3), and the access count X to which "1" has been added is stored at the same address in the memory (step 35 in FIG. 3).

At this time, the statistical information storage circuit 12 compares the number of accesses X to which "1" has been added and the maximum number of accesses held in advance (step 36 in FIG. 3).
becomes larger than the maximum number of accesses (X≧MAX
), the cylinder address is registered as the maximum number of accesses cylinder (step 37 in FIG. 3), and the number of accesses X is also held as the maximum number of accesses (step 38 in FIG. 3).

If the number of accesses X does not become larger than the maximum number of accesses (X<MAX), the storage process in the statistical information storage circuit 12 ends, and the processing in the magnetic disk device 1 continues as it is.

When the magnetic disk device 1 continues to be in a state where it is not accessed by the host device, and the timer circuit 16 outputs the timer signal 108 to the control circuit 11 to notify that the time without access from the host device has exceeded the threshold, the control circuit 1
1 operates based on the statistical information stored in the statistical information storage circuit 12.

That is, the control circuit 11 outputs the read signal 10B to the statistical information storage circuit 12, and sends the cylinder data 104 read from the statistical information storage circuit 12, that is, the cylinder address with the maximum number of accesses, to the cylinder storage circuit 14 via the selection circuit 13. let it hold.

The control circuit 11 activates the positioning control circuit 15 at the next timing.
Execution signal 107 for performing positioning operation on
is output, and the head disk assembly 17 performs a positioning operation based on the cylinder address having the maximum number of accesses read from the statistical information storage circuit 12.

Therefore, the magnetic head (not shown) is moved from the currently positioned head position 22a on the cylinder 22 to the head position 23a on the cylinder 23 that has been accessed the maximum number of times.

If the magnetic disk device 1 remains unaccessed by a host device for a long time, there is no possibility that data will be read or written to the currently positioned cylinder address, and the next access will always be made to another cylinder. Based on the inference that a read command or a write command accompanied by a move command to the address will be sent, the cylinder address is positioned in advance at a cylinder address that is frequently accessed.

However, when the currently positioned cylinder address is the cylinder address with the maximum number of accesses, the positioning operation is performed for the cylinder address with the next highest number of accesses after the maximum number of accesses.

However, if the access from the host device is to a cylinder address that is different from the cylinder address determined by the statistical information, the magnetic head must be moved (1 is when there is no access from the host device). If the cylinder address is moved to the cylinder address with the maximum number of accesses, that is, the predicted cylinder address that is most likely to be accessed, the magnetic head does not need to be moved when the host device accesses the predicted cylinder address. , access speed can be improved.

FIG. 4 is a diagram showing positioning control based on the number of accesses per unit time (access frequency) according to an embodiment of the present invention, and FIG. 5 shows the storage operation of the access frequency in the statistical information storage circuit 12 of FIG. FIG.

Positioning control based on access frequency according to an embodiment of the present invention will be explained using FIG. 1, FIG. 4, and FIG. 5.

In the magnetic disk device 1, access is made to each of the cylinders 21 to 24 from the outermost cylinder 21 to the innermost cylinder 24 in which data is recorded among the outer shape 20 to the inner shape 25 of the magnetic disk medium 2. The number of times is stored in the statistical information storage circuit 12.

That is, as shown in steps 31 to 38 in FIG.
When an access command is input from the host device, the statistical information storage circuit 12 converts the cylinder address from the host device into a memory address, and reads out the contents stored in the memory of the statistical information storage circuit 12 using the memory address. Then, "1" is added to the content read from this memory, that is, the number of accesses X of the cylinders 21 to 24, and the result is stored at the same address in the memory.

At this time, the statistical information storage circuit 12 compares the number of accesses X to which "1" has been added and the maximum number of accesses held in advance, and if the number of accesses X becomes greater than the maximum number of accesses (xaMAX), the cylinder The address is registered as a maximum access count cylinder, and the access count X is held as the maximum access count.

If the number of accesses X does not become larger than the maximum number of accesses (x<MAX), the storage process in the statistical information storage circuit 12 continues as is.

In the statistical information storage circuit 12, each cylinder 21 to 24
In order to calculate the access frequency for each cylinder, a timer interrupt is generated at regular intervals (step 41 in FIG. 5), and the number of accesses for each cylinder 21 to 24 stored in memory is subtracted (step 41 in FIG. 5). Step 42), and the timer interrupt is terminated (Step 43 in FIG. 5). Thereby, the access frequency is stored in the memory of the statistical information storage circuit 12.

At this time, the maximum number of accesses is also subtracted, and the maximum access frequency is calculated and held.

When the magnetic disk device 1 continues to be in a state where it is not accessed by the host device, and the timer circuit 16 outputs the timer signal 108 to the control circuit 11 to notify that the time without access from the host device has exceeded the threshold, the control circuit 1
1 operates based on the statistical information stored in the statistical information storage circuit 12.

That is, the control circuit 11 outputs a read signal 103 to the statistical information storage circuit 12, and holds the cylinder data 104 read from the statistical information storage circuit 12 and the cylinder address with the highest access frequency in the cylinder storage circuit 14 via the selection circuit 13. let

The control circuit 11 activates the positioning control circuit 15 at the next timing.
Execution signal 107 for performing positioning operation on
is output, and the head disk assembly 17 performs a positioning operation based on the cylinder address with the highest access frequency read from the statistical information storage circuit 12.

Therefore, the magnetic head is currently positioned in cylinder 2.
from the head position 22b on the cylinder 23 to the head position 23b on the cylinder 23 with the highest access frequency.

In this case as well, if the cylinder address currently being positioned is the cylinder address with the highest access frequency,
A positioning operation is performed for the cylinder address that has the next highest access frequency after the highest access frequency.

As a result, when there is no access from the host device, if the cylinder address is moved to the most frequently accessed cylinder address, that is, the predicted cylinder address that is most likely to be accessed, the access from the host device will be the access to the predicted cylinder address. In this case, the magnetic head does not need to be moved, so the access speed can be improved.

In this way, each cylinder 21 to 2 of the magnetic disk medium 2
Statistical information such as the number of accesses or access frequency in 4.
That is, the usage status of each cylinder 21 to 24 of the disk medium 2 is stored in the statistical information storage circuit 12, and the magnetic head is moved to a predicted cylinder address based on the statistical information before receiving an access command from the host device. By doing so, the waiting time due to positioning operations that always occur in conventional control is less likely to occur, so read or write operations can be executed immediately by access commands from the host device, and the system or magnetic disk device can be operated efficiently.

Although the embodiment of the present invention has been described with respect to the magnetic disk device 1, it is obvious that the present invention can be applied to other disk devices, and is not limited thereto.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the usage status is stored for each cylinder of a disk medium, and when no access from a host device is input for a predetermined period of time,
By changing the position of the head on the disk medium according to the stored usage status, there is an effect that the system or device can be operated efficiently.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention, FIG. 2 is a diagram showing positioning control based on the number of accesses in one embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of the statistical information storage circuit of FIG. 1. 4 is a flowchart showing the storage operation of the number of accesses, FIG. 4 is a diagram showing positioning control based on the number of accesses per unit time in an embodiment of the present invention, and FIG. 5 is a flowchart showing the access frequency in the statistical information storage circuit of FIG. 1. FIG. 6 is a block diagram showing a conventional system configuration. Explanation of symbols of main parts 1...Magnetic disk device 2...Magnetic disk medium 11...Control circuit 12...Statistical information storage circuit 13... ... Selection circuit 14 ... Cylinder memory circuit 15 ... Positioning control circuit 16 ... Timer circuit

Claims (1)

[Claims] (1) A storage means for storing usage status for each cylinder of a disk medium, and when no access from a host device is input for a predetermined period of time, the usage status stored in the storage means is stored in the disk medium. 1. A disk device comprising: changing means for changing the position of a head on a medium.