JPH0225954A - Disk device - Google Patents

Abstract

PURPOSE:To realize a high-speed access to the data having a high access frequency just with an electrical switching operation and to improve the overall throughput of a disk device by using a high-speed memory which needs no seeking action nor rotation waiting action. CONSTITUTION:A high-speed memory 2 stores the data having a high access frequency of a disk device 8, e.g., a directory part, etc. In a normal input/output action state, it is decided whether a track where the information is written or read out by a control circuit 6 with an input/output signal 9 is set on an HD (head disk) mechanism system assembly 1 or the memory 2. In case of the latter state, the information is recorded and reproduced at the memory 2 via a high-speed memory access circuit 3. In this case, an access is possible to the memory 2 for record/reproduction of information just with the conversion of addresses carried out by the circuit 3. Thus the working speed is extremely increased for a disk device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to external memories for computer systems, communication systems, etc., and particularly to randomly accessible disk memories.

[Conventional technology]

Regarding conventional devices, see IBM, Journal of Research and Development, Vol. 18,
(1974) pp. 489-505 (I B M
,J,RES,DEVELOP,VOl,1
8° Nov, 1974. PP489-505).

[Problem to be solved by the invention]

As shown in FIG. 2, the above conventional technology includes a head-disk mechanism assembly 1 (hereinafter abbreviated as HD assembly).
A plurality of fixed heads 10 are prepared to record frequently accessed data. Access to the fixed head is achieved only by electrical head switching. Therefore, the number of data input/outputs per unit time (throughput) of the device as a whole is improved compared to a model without a fixed head. However, when accessing target data with a fixed head, there is a rotational wait time due to the rotation of the disk, so although the louput is roughly doubled compared to a movable head, it does not improve by an order of magnitude. Furthermore, since the fixed head does not have a head positioning mechanism, the track density is limited by thermal displacement, etc., and there are problems such as difficulty in recording data on a large number of movable tracks on the fixed head.

An object of the present invention is to enable high-speed access to frequently accessed data using only electrical switching, thereby significantly improving the throughput of the entire device.

[Means to solve the problem]

The above purpose is to implement a high-speed accessible memory such as a semiconductor memory in a disk device, transcribe data on frequently accessed tracks (or cylinders), and access the high-speed memory for data on these tracks or cylinders. This is achieved by performing recording and reproducing.

[Effect]

Data in frequently accessed tracks (or cylinders) is recorded in high speed memory. Therefore, since access to these frequently accessed data is performed by electrical switching, seek time for head positioning system and disk rotation waiting time are eliminated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. The disk device 8 according to the present invention includes a head-disk-mechanism assembly 1. Recording/reproducing circuit 4, positioning circuit 5. Control circuit 6, interface circuit 7. It consists of a high speed memory 2 and a high speed memory access circuit 3. As described above, the high-speed memory 2 stores frequently accessed data of the disk device 8, such as a directory section. When the device is powered on,
The information to be stored in the high-speed memory 2 is transferred from the marking track of the HD assembly 1 to the high-speed memory 2 via the recording/reproducing circuit 4 and the high-speed memory access circuit 3 under the control of the control circuit 6. be done. During normal input/output operation, the control circuit 6 uses the input/output signal 9 to determine whether the track on which information is written or read is on the F1/D assembly 1 or the high speed memory 2. In the former case, information is recorded and reproduced via the recording and reproducing circuit 4, as in conventional disk devices. If the latter information is present, the information is recorded and reproduced in the high speed memory via the high speed memory access circuit 3. In this case, for recording and reproducing information, access to the high-speed memory 2 is possible only by address conversion by the high-speed memory access circuit 3, so the conventional HD assembly]
This makes it possible to speed up information access by approximately 4 orders of magnitude compared to accessing information using .

When the device is powered off, data is transmitted from the high-speed memory 2 via the high-speed memory access circuit 3, control circuit 6, and recording/reproducing circuit 4.
The information is transferred to the corresponding track on the HD assembly and stored as non-volatile information on the disk.6 In addition, in case of device failure or temporary power cut, the high-speed memory access circuit has a backup It is equipped with a power supply, which enables the high-speed memory 2 to retain information for a short period of time, for example, about 48 hours.

As the high-speed memory 2, a semiconductor memory element such as DRAM is suitable, and the capacity is several shillings (m2) of a disk device.
track in the case of a board) to approximately 1/10 of the device memory capacity.
A value of about 00 is valid.

HD assembly 1, recording/reproducing circuit 4, positioning circuit 5. The interface circuit 7 is the same as that known and commonly used. The HD assembly 1 is a floppy disk device, in addition to a conventional one equipped with a stack of a plurality of magnetic disks, a positioning mechanism, and a plurality of head assemblies.

A head/medium 1 mechanism system assigned to a disk device using a replaceable medium such as a magneto-optical device may also be used.

The above-mentioned embodiments are mainly for small-sized disk devices, but a second embodiment for a large-sized disk device will be explained with reference to FIGS. 3 and 4.

In a large computer system, data is written to and read from a disk device through a central processing unit 11, an input/output processing unit 12, and a disk control device 13. In a large system, multiple disk drives 15 , 16 make up a disk drive string 14 , and the strings are connected to the disk controller 13 .

In a large disk device, a common control section 17 of a disk device with a common control section [15] placed at the head of a disk device string 14 modulates storage information from an input/output processing device and also discriminates information from the disk device. , demodulation is performed. Therefore, in this embodiment, a high-speed memory group 18 is installed in the common control unit 17 to store information that is frequently accessed by each disk device. Other operations and controls are the same as in the first embodiment, and if the data accessed to the disk device is stored on a high-speed memory, high-speed data access is possible without seeking or waiting for rotation. Also, when the power of the disk device is turned on and off, data is transferred onto the high-speed memory and recorded from the high-speed memory to the corresponding track of the assigned disk device, similarly to the first embodiment. The same goes for having a battery and backup power source for holding high-speed memory data.

In the first and second embodiments described above, a volatile semiconductor memory is used, but a non-volatile memory may also be used.

In particular, in the case of a disk device that is not a medium-replaceable type, by using a nonvolatile memory and making specific track data resident, it is possible to eliminate the need for high-speed memory and transfer between disk devices when power is turned on and off.

Furthermore, by implementing the above-mentioned disk device in a word processor or personal computer, access to directory data, etc. can be greatly speeded up, so that writing and reading of data exceeding one track in particular can be done at high speed.

〔Effect of the invention〕

According to the present invention, data that is frequently accessed can be accessed approximately four orders of magnitude faster than when using a normal positioning mechanism, resulting in a significant improvement in throughput as a device.

In addition, with the present invention, the user only needs to be aware of storing data that is clearly frequently used on a specific track that supports high-speed memory, and the rest is completely equivalent to a normal disk device with guaranteed non-volatility. It is. During operation, only the input/output operation of a specific track becomes faster, so that when the hit rate is low when using the cache memory, the 5-day disadvantage of lowering the relative throughput when there is no cache does not occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of a conventionally known example. FIGS. 3 and 4 are configuration diagrams of the second embodiment.

Claims (1)

[Scope of Claims] 1. A disk device characterized by being equipped with a high-speed memory that does not require seek operations or rotation wait operations. 2. In claim 1, when the power of the disk device is turned on, specific track information of the disk device is transferred to and recorded on the high-speed memory, and during normal operation, information is written to and read from the specific track on the high-speed memory. A disk device characterized by recording information in a high-speed memory on a corresponding specific track when the power is cut off. 3. In the disk device string, in the common control section,
A disk device characterized by being provided with a high-speed memory group that does not require seek operations or rotational wait operations. 4. Scope of the Claims In claim 3, when the disk device power is turned on, specific track information on each disk device on the string is transferred and recorded to the corresponding memory portion in the high-speed memory group, and during normal operation, A disk device characterized in that information on a specific track of each disk device is written and read on a corresponding high-speed memory, and when power is cut off, information in the high-speed memory group is recorded in a specific track of the corresponding disk device. . 5. In word processors and personal computers, the installed disk device is equipped with a high-speed memory, and specific track information is transferred and recorded when the device is powered on, and during normal operation, information is written to and read from specific tracks on the high-speed memory. A word processor and a personal computer, characterized in that information in a high-speed memory is recorded in a corresponding specific track when the power is cut off. 6. A disk device according to claim 1, 3, or 5, characterized in that a nonvolatile memory is used as the high-speed memory.