JPH0468431A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To execute the information transmission at a high speed at the time of device cross call by providing a disk cache part on each of each housing in which each of magnetic disk control parts is installed separately. CONSTITUTION:Disk cache parts 5, 6 are provided on each of each housing 8, 9, and when a magnetic disk control part 3 executes a write or read/out request of information to a magnetic disk device 7, when the information concerned does not exist in the disk cache part 5, write or read-out of the information is executed to the magnetic disk device 7, and simultaneously, said information is accumulated in the disk cache part 5. In that case, the information is accumulated in the same way in the disk cache part 6, as well of a magnetic disk control part 4 through a cable 10, and the contents of the disk cache part 5 and the disk cache part 6 are always allowed to match with each other. In such a way, at the time of constituting an inter-housing cross call, even with respect to a request from any magnetic disk control part, the processing can be executed at a high speed by sending the contents of the own disk cache part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to disk cache control means for a magnetic disk subsystem used in an information processing system.

〔overview〕

The present invention provides a magnetic disk control device that uses a disk cache to make cross-calls to a magnetic disk device, and by providing a disk cache for each magnetic disk control unit, it is possible to speed up information transfer. This is how it was done.

[Conventional technology]

Conventionally, this type of disk cache section 5 is connected between the magnetic disk control sections 3 and 4, as shown in FIG. 2, and receives write or read requests from the magnetic disk control section 3 or 4 to the magnetic disk device 7. The information obtained at the time is stored in the disk cache section 5, and when a read request is subsequently made from the magnetic disk control device 3 or 4 to the magnetic disk device 7, the desired information is stored in the disk cache section 5. If the information is stored in the magnetic disk drive 7, the information stored in the disk cache unit 5 is transferred to the magnetic disk control unit 3 or 4 without making a read request to the magnetic disk unit 7, and the central processing unit 1 and input/output control Device 2
The processing time of information processing systems including

Furthermore, the operation when cross-calling between cases is performed will be explained using FIG. 3. A disk cache section 5 and a magnetic disk control section 3 are mounted within the casing 8, and a magnetic disk control section 4 is mounted within the casing 9. The magnetic disk control section 3 and the magnetic disk control section 4 are connected by a disk cache section 5, a cable 10, and a cable 11. Information when a write or read request is made from the magnetic disk control unit 3 or 4 to the magnetic disk device 7 is stored in the disk cache unit 5, and then read from the magnetic disk control unit 3 or 4 to the magnetic disk device 7. If the desired information is stored in the disk cache section 5 when a request is made, the information stored in the disk cache section 5 is transferred to the magnetic disk without making a read request to the magnetic disk device 7. Control unit 3 or 4
The processing time of the information processing system including the central processing unit 1 and the input/output control unit 2 is accelerated.

[Problem to be solved by the invention]

In such conventional examples, when a read request is made to a magnetic disk device from a magnetic disk control unit in a separate chassis from the chassis in which the disk cache unit is mounted, the desired information is stored in the disk cache unit. If the information has been stored, the information stored in the disk cache unit is transferred to the magnetic disk control unit in another housing through the inter-casing cable without issuing a read request to the magnetic disk device. For this reason, ■ When information is transferred from the disk cache unit to the magnetic disk control unit in a separate chassis, it is slower than the transfer to the magnetic disk control unit in the same chassis, which defeats the purpose of high-speed processing; , ■ If the inter-casing cable becomes longer, the information transfer speed of the disk cache section will be delayed accordingly, and there is a drawback that the cases that perform inter-casing cross calls cannot be separated far apart.

SUMMARY OF THE INVENTION The present invention aims to eliminate such drawbacks and provides a magnetic disk control device that can perform high-speed information transmission during device cross calls.

[Means to solve the problem]

The present invention includes a plurality of magnetic disk control units that cross-call the same magnetic disk device, and a disk cache unit whose contents are updated each time one of the magnetic disk control units makes a write or read request to the magnetic disk device. and a magnetic disk control device in which each of the magnetic disk control units is mounted in a separate housing, characterized in that each of the housings is provided with the disk cache unit. Here, the number of the casings may be two.

It also includes a plurality of magnetic disk control units that cross-call the same magnetic disk unit, and a disk cache unit whose contents are updated each time one of the magnetic disk control units makes a write or read request to the magnetic disk unit. A magnetic disk control device in which each of the magnetic disk control units is mounted in one housing is characterized in that the above-mentioned disk cache unit is provided corresponding to each magnetic disk control unit.

[Effect]

When the magnetic disk control unit writes or reads information to or from the magnetic disk device, if the desired information does not exist in the disk cache unit, the writing or reading is performed to or from the magnetic disk unit, and at the same time the disk cache unit and other The same information is stored in the disk cache section.

Furthermore, if the disk cache section has desired information, the information stored in the disk cache section is read out.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of this embodiment. 1st
In the figure, elements similar to those in FIG. 3 are numbered the same.

A magnetic disk control section 3 with a built-in disk cache section 5 is mounted in the casing 8, and a magnetic disk control section 4 with a built-in disk cache section 6 is mounted in the casing 9. The magnetic disk control section 3 and the magnetic disk control section 4 are connected by a cable 10. The magnetic disk control section 3 and the magnetic disk control section 4 are connected to a magnetic disk device 7, and have an inter-casing cross-call configuration.

As shown in FIG. 1, this embodiment includes two magnetic disk controllers 3 and 4 that cross-call the same magnetic disk device 7, and a magnetic disk device 7 by one of the magnetic disk controllers 3 and 4. Each of the casings 8 and 9 is provided with disk cache units 5 and 6, the contents of which are updated each time a write or read request is made.

Next, the operation of this embodiment will be explained.

When the magnetic disk control unit 3 makes a request to write or read information to the magnetic disk device 7, if there is no corresponding information in the disk cache unit 5, the information is written to or read from the magnetic disk device 7, At the same time, the same information is stored in the disk cache unit 5. At this time, the data is similarly accumulated in the disk cache section 6 of the magnetic disk control section 4 through the cable 10, so that the contents of the disk cache section 5 and the disk cache section 6 always match. At this time, even if the cable 10 is long and the writing time to the disk cache section 6 is delayed from the storage time to the disk cache section 5, it is faster than writing to or reading from the magnetic disk device 7.

After that, when a read request to the magnetic disk device 7 is made to the magnetic disk control unit 3 or 4, if the desired information is stored in the built-in disk cache unit,
The magnetic disk controller 3 or 4 is a magnetic disk device 7.
The information stored in its own disk cache unit is transferred to the central processing unit 1 and the input/output control unit 2 without issuing a read request to the CPU. This makes it possible to perform high-speed processing by sending the contents of its own disk cache section in response to a request from any magnetic disk control section when configuring an inter-casing cross call.

Note that even if there are a plurality of cases in which a plurality of magnetic disk control units are mounted, the device cross call of the above method is possible by providing each magnetic disk control unit with a disk cache.

This is also possible even when the magnetic disk control unit uses the disk cache to perform device cross calls only within the same housing.

〔Effect of the invention〕

As explained above, unlike the conventional device cross call using a disk cache, the present invention has a disk cache section in each magnetic disk control section.
Even when a device cross call is performed, ■ Even when information is transferred from a separate magnetic disk control unit to the disk cache unit, the information transfer is performed at high speed. ■ Even when the cable between the chassis is long, the magnetic disk control Since there is no delay in the information transfer speed from the disk cache section in response to a read request from the section, there is an effect that the casings that perform device cross calls can be installed apart from each other.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a general information processing system including a disk cache. FIG. 3 is a block diagram showing the configuration of an inter-box cross call using a conventional disk cache. 1... Central processing unit, 2... Human output control device, 3.
4... Magnetic disk control unit, 5.6... Disk cache unit, 7... Magnetic disk device, 8.9...
Housing, 10.11...Cable.

Claims (1)

[Claims] 1. A plurality of magnetic disk control units that cross-call the same magnetic disk device, and each time one of the magnetic disk control units makes a write or read request to the magnetic disk device, the contents are updated. A magnetic disk control device comprising: a disk cache unit, wherein each of the magnetic disk control units is mounted in a separate housing, characterized in that each housing is provided with the disk cache unit. Control device. 2. The magnetic disk control device according to claim 1, wherein the number of said housings is two. 3. A plurality of magnetic disk control units that cross-call the same magnetic disk device, and a disk cache unit whose contents are updated each time one of the magnetic disk control units makes a write or read request to the magnetic disk device. What is claimed is: 1. A magnetic disk control device comprising: each of the magnetic disk control units mounted in a single housing; the magnetic disk control device comprising: the disk cache unit corresponding to each magnetic disk control unit;