JPH05282107A - External storage device - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the access speed of a low-capacity external storage device such as a magneto-optical storage device. According to the external storage device of the present invention, a mass storage device and a magnetic storage device are built in one housing, and the data stored in the mass storage device is transferred to the magnetic storage device at the time of access and stored in the magnetic storage device. Output from the storage device to the outside. Further, even among data stored in the magnetic storage device, data that has not been accessed for a certain period of time is returned from the magnetic storage device to the mass storage device. At this time, the data updated in the magnetic storage device is stored in the mass storage device. Update when returning to. In this way, the operation of the low-speed mass storage device is minimized, and the relatively high-speed and large-capacity magnetic storage device is accessed from the outside, so that the data access waiting time, the data transfer time, Reduce the amount of data on the transfer path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external storage device.

[0002]

2. Description of the Related Art Conventionally, an external storage device such as a magneto-optical storage device can store a large capacity as compared with a magnetic storage device, but on the other hand, there is a problem that the access speed is slow.

Therefore, in a system equipped with a large-capacity storage device, when the data in the storage device is repeatedly accessed for several times, the first access is made in order to reduce the waiting time during data access. At one time, the data was collectively transferred to another high-speed storage device in the system and then accessed.

Further, in a small-scale system, a semiconductor memory is provided in a storage device in which data is temporarily stored so that high speed access can be performed.

[0005]

However, in such a conventional external storage device, when the system handles large-scale data, it takes a long time to transfer the data, and due to the transfer. There was a problem of occupying the transfer path.

Further, when the semiconductor memory is provided, there is a problem that it is too costly to store large-scale data and cannot be put to practical use.

The present invention has been made in view of the above-mentioned conventional problems, and an external storage device capable of high-speed access to a large-capacity, low-speed storage device at relatively low cost. The purpose is to provide.

[0008]

SUMMARY OF THE INVENTION An external storage device of the present invention is a random-accessible large-capacity storage device and a magnetic storage device capable of relatively small-capacity and relatively high-speed access to the large-capacity storage device. When accessing the storage device and the mass storage device from the outside, the corresponding storage data is temporarily stored in the magnetic storage device, output from the magnetic storage device to the outside, and write data from the outside is stored in the magnetic storage device. A storage unit control device that controls to write once in a storage device and then write in the mass storage device is built in as one device.

[0009]

In the external storage device of the present invention, the data stored in the mass storage device is transferred to the magnetic storage device at the time of access, and is output to the outside from the magnetic storage device. Both storage devices are managed by the storage unit control device so as to transfer again to the mass storage device. As a result, data in the magnetic storage device is accessed from the outside, and writing is also performed on the data in the magnetic storage device.

Further, the storage unit control device has a directory, and controls transfer from the mass storage device to the magnetic storage device and control for transferring unaccessed data in the magnetic storage device to the mass storage device.

Thus, the operation of the low-speed mass storage device is minimized, and the magnetic storage device of relatively high speed and large capacity is accessed from the outside, so that the waiting time for data access and the data The transfer time and the amount of data on the transfer path are reduced.

[0012]

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

FIG. 1 shows the system configuration of an embodiment of the present invention, and FIG. 2 particularly shows the detailed configuration of the control device.

In FIG. 1, reference numeral 1 is a magnetic storage device,
Data accessed from outside is stored here once. Reference numeral 2 is a mass storage device such as a magneto-optical storage device which has a slow access speed but can store a large amount of data, and all data in the system is stored here.
Reference numeral 3 denotes a control device for performing internal control of the external storage device, which controls data transfer between the magnetic storage device 1 and the mass storage device 2 and manages data in the two storage devices 1 and 2.

An input / output circuit 4 exchanges data between this device and an external computer. A control signal line 5 transmits a control signal when the control device 3 controls the storage devices 1 and 2 and exchanges data. A data signal line 6 transmits a data signal between the storage devices 1 and 2, and between the storage device 1 and the input / output circuit 4.

Then, the control device 3 is, as shown in FIG.
A magnetic memory device data writing / reading control unit 31 for controlling data writing / reading of the magnetic memory device 1,
Mass storage device data write / read control unit 3 for controlling data write / read of the mass storage device 2
2, an input / output circuit control unit 33 that controls the input / output operation of the input / output circuit 4, an access frequency monitoring unit 34 that monitors the access frequency to the data stored in the magnetic storage device 1, and an overall control that controls these units. It is composed of a section 35.

Next, the operation of the external storage device having the above configuration will be described.

When there is a data access request from a computer (not shown) connected via the input / output circuit 4, the controller 3 determines the requested data by the input / output circuit controller 33. , It is judged whether or not the requested data is stored in the write / read controller 31 for the magnetic storage device, and if it is not stored, the data write / read controller 31 for the magnetic storage device, data write / read for the mass storage device 31 The read controller 32 controls the mass storage device 2
The corresponding data is transferred to the magnetic storage device 1.

Further, the access frequency monitoring unit 34 of the control device 3
Monitors the access frequency of the data in the magnetic storage device 1 and updates and stores the data, which has not been accessed for a certain time or more, from the magnetic storage device 1 to the mass storage device 2. Then, in the magnetic storage device 1, the data area after being retransferred to the mass storage device 2 is set as an unused area by the magnetic storage device data writing / reading control unit 31.

The control unit 3 controls the data read / write operation with respect to the external storage device as follows.

<< Read Operation >> 1) A computer connected via the input / output circuit 4 attempts to read the data stored in the mass storage device 2.

2) Since the mass storage device 2 is slow in reading data, it takes time to read the same data a plurality of times, so the control device 3 transfers the data to the magnetic storage device 1 at the time of the first reading. ..

3) Simultaneously with the transfer of data to the magnetic storage device 1, the control device 3 outputs the data from the input / output circuit 4 to the outside.

4) The second and subsequent reading of data is output from the magnetic storage device 1 through the input / output circuit 4.

<< Write Operation >> 1a) When changing the data stored in the mass storage device 2, the control device 3 once transfers the data to the magnetic storage device 1.

1b) When changing the data already transferred to the magnetic storage device 1, the data stored in the magnetic storage device 1 is changed as it is. (When changing after read operation) 2) After the operation of 1a) or 1b), if the data is no longer accessed for a certain period of time, the control device 3 stores the data stored in the magnetic storage device 1 in the mass storage device. Store in 2.

Thus, in a mass storage device such as a magneto-optical storage device, a relatively high-speed magnetic storage device is built in, and the accessed data is temporarily transferred to and held in this magnetic storage device. Write to data,
By reading, the data access speed to the low-speed mass storage device is increased.

When a magneto-optical disk device is used as the mass storage device and a large-scale storage system is constructed by attaching an autochanger, the mass storage including the magneto-optical disk device and the autochanger is large. By adding a magnetic storage device to the storage device, the external storage device of the present invention can be configured.

[0029]

As described above, according to the present invention, a large-scale data can be handled, but a low-speed mass storage device can be accessed at high speed, and a normal magnetic storage device is used. It is possible to configure a relatively high-speed and large-capacity external storage device that is the same as the above case. Moreover,
As compared with the case where a semiconductor memory that temporarily holds a large amount of data is used, large data can be handled at a lower cost.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a detailed internal configuration of a control device in the above embodiment.

[Explanation of symbols]

1 Magnetic Storage Device 2 Mass Storage Device 3 Control Device 4 Input / Output Circuit 5 Control Signal Line 6 Data Signal Line 31 Magnetic Storage Device Data Writing / Reading Control Unit 32 Mass Storage Device Data Writing / Reading Control Unit 33 Input / Output Circuit control unit 34 Access frequency monitoring unit 35 Overall control unit

Claims (1)

[Claims] 1. A mass storage device capable of random access, a magnetic storage device capable of relatively small capacity and relatively high-speed access to the mass storage device, and an external mass storage device. When accessing, the corresponding storage data is temporarily stored in the magnetic storage device, output from the magnetic storage device to the outside, and write data from the outside is once written to the magnetic storage device, and then the mass storage device. An external storage device that includes a storage unit control device that controls writing to a storage device as one device.