JPH04239353A - Disk cache device - Google Patents

Abstract

PURPOSE:To make clear the factor of an information illicit fault in a short time by adding the function of a cache saving control part into a disk cache device. CONSTITUTION:A cache saving control pert 46 receives and stores the updating data information that is given to a cache memory part 45 from a data transfer part 43-1. Then the part 46 gives an instruction to an interface part 41 to write the stored updating date information into a spare area of a magnetic disk 5, etc. Thus the part 41 writes the updating data information of the part 45 into the spare area of the disk 5 with an instruction of the part 46 while an access instruction is given to the device 5 from a magnetic disk controller 3. Thus the factor of an information illicit fault can be made clear in a short time.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk cache device used in an information processing system.

0002

2. Description of the Related Art Conventionally, this type of disk cache device is connected between a magnetic disk control device 3 and a magnetic disk device 5, as shown in FIG. /Accumulates the information at the time of the read request in the disk cache device 4, and then transfers the information from the magnetic disk control device 3 to the magnetic disk device 5.
If the target information is stored in the disk cache device 4 when a read request is made to the disk cache device 4, the read request is not made from the disk cache device 4 to the magnetic disk device 5, and the target information is stored in the disk cache device 4. The information accumulated in the cache device 4 is transferred to the magnetic disk control device 3, thereby speeding up the processing time of the information processing system including the central processing unit 1 and the input/output control device 2.

Further, the operation of the conventional disk cache device will be explained in detail with reference to FIG.

When a read request is issued from the magnetic disk control device 3 to the magnetic disk device 5, the interface control section 41 in the disk cache device 4 once receives the instruction from the magnetic disk control device 3, and sends the instruction to the cache control section 44. Communicate the instructions.

[0005] The cache control unit 44 includes the control table unit 4
2, it is checked whether the track on the magnetic disk device 5 that the magnetic disk control device 3 attempts to access exists in the cache memory section 45. If the corresponding track exists in the cache memory section 45, the cache control section 44 instructs the data transfer section 43 to transfer the corresponding information to the magnetic disk control device 3 via the interface control section 41.

[0006] If the corresponding track does not exist in the cache memory section 45, the cache control section 44 requests the corresponding information from the magnetic disk device 5 via the interface control section 41, and the transferred information is The magnetic disk controller 3 via the interface controller 41
At the same time, the track information is stored in the cache memory section 45 through the data transfer section 43, and the track information is stored in the control table section 42 in preparation for a subsequent read request from the magnetic disk control device 3 to the magnetic disk device 5.

[0007] Furthermore, when a write request is made from the magnetic disk control device 3 to the magnetic disk device 5,
The interface control section 41 directly instructs the magnetic disk device 5 to write to the magnetic disk device 5, and also instructs the cache control section 44 to register in the same manner. The cache control unit 44 instructs the data transfer unit 43 to store information to be transferred from the magnetic disk control device 3 to the magnetic disk device 5 in the cache memory unit 45, and stores the track information in the control table 42. , in preparation for a subsequent read request from the magnetic disk control device 3 to the magnetic disk device 5.

[0008]

[Problems to be Solved by the Invention] In the conventional disk cache device described above, when a read request is made from the magnetic disk control device to the magnetic disk device as described above, the target information is stored in the disk cache device. If the disk cache is stored in Failure detection, such as when incorrect information is being transferred to the magnetic disk controller when there is a failure in the device, or when incorrect information is being transferred to the magnetic disk controller when there is a failure or other failure in the magnetic disk device. Sometimes, there is a drawback that a considerable amount of investigation and searching is required before it is determined whether the cause lies in the disk cache device or the magnetic disk device.

The biggest reason for this drawback is that the contents of the cache memory section cannot be saved because the contents of the cache memory section are constantly updated in response to requests for information transfer from the magnetic disk control device to the magnetic disk device. Depends on the situation.

0010

[Means for Solving the Problems] A disk cache device according to a first aspect of the invention updates a cache memory section provided in advance in a disk cache device connected between a magnetic disk control device and a magnetic disk device. a cache control unit that outputs update status information at each time; and a cache control unit that receives the update status information, temporarily stores the update information, and writes the update information to a predetermined area of a magnetic disk device provided in advance. A cache save control section that instructs the write instruction, and a data transfer section that receives the write instruction and outputs the update information to the area.

[0011] Further, the disk cache device of the second invention is a disk cache device connected between a magnetic disk control device and a magnetic disk device, and includes a cache storage storage section, and a cache memory section provided in advance. The cache control unit stores update information in the cache storage unit each time an update is performed.

0012

Embodiments Examples of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a disk cache device according to the present invention.

In FIG. 1, the same elements as in FIG. 4 are given the same numbers, and in FIG. 1, the function of a cache save control section 46 is added to the disk cache device 4-1.

As mentioned above, the cache control unit 44-1
Normally, when there is a corresponding track of the magnetic disk device 5 in the cache memory section 45 by referring to the control table section 42 at the time of a read request from the magnetic disk control device 3, or when a write request is made from the magnetic disk control device 3. The transfer operation between the magnetic disk control device 3 and the magnetic disk device 5 is performed, and the contents of the cache memory section 45 are updated.

The cache control unit 44-1 notifies the cache save control unit 46 of the update status each time the cache memory unit 45 is updated, and the cache save control unit 46 updates the cache memory unit 45 transferred from the data transfer unit 43-1.
Receives and stores updated data information.

The cache save control section 46 instructs the interface control section 41 to write the accumulated update information of the cache memory section 45 into a predetermined spare area of the magnetic disk device 5 or the like.

The interface control unit 41 controls the magnetic disk control device 3 according to instructions from the cache save control unit 46.
The above-mentioned update information of the cache memory unit 45 is written in a spare area of the magnetic disk device 5 or the like between access instructions to the magnetic disk device 5 from the above.

[0019] As a result, the update history information of the cache memory unit 45, which is constantly updated, can be saved in a predetermined reserve such as the magnetic disk device 5.

FIG. 2 is a block diagram showing another embodiment of the disk cache device according to the present invention.

In FIG. 2, elements similar to those in FIG. 4 are given the same numbers, and in FIG.
functionality has been added.

As mentioned above, the cache control unit 44-2
Normally, when there is a corresponding track of the magnetic disk device 5 in the cache memory section 45 by referring to the control table section 42 at the time of a read request from the magnetic disk control device 3, or when a write request is made from the magnetic disk control device 3. The transfer operation between the magnetic disk controller 3 and the magnetic disk device 5 is performed, and the contents of the cache memory section 45 are updated.

Each time the cache memory section 45 is updated, the cache control section 44-2 accumulates the updated information in the cache accumulation storage section 47.

[0024] As a result, update history information of the cache memory section 45, which is constantly updated, can be saved in the cache storage section 47.

[0025]

As is clear from the above description, the present invention provides a method for saving and storing information in a cache memory section in a conventional disk cache device in a predetermined area in a magnetic disk device. With the addition of a cash evacuation control unit that increases the amount of gold,
When investigating the cause of an information malfunction, it is important to determine whether the problem is with the disk cache device or with the magnetic disk device. By comparing the information in the spare area within the device, it can be determined in a short time, and the benefits obtained are significant.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a disk cache device of the present invention.

FIG. 2 is a block diagram showing another embodiment of the disk cache device of the present invention.

FIG. 3 is a block diagram showing an example of a conventional disk control system.

FIG. 4 is a block diagram showing an example of a conventional disk cache device.

[Explanation of symbols]

1 Central processing unit 2 Input/output control device 3 Magnetic disk control device 4 Disk cache device 5 Magnetic disk device 41 Interface control section 42 Control table section 43 Data transfer section 44 Cache control section 45 Cache memory section 46 Cache save control section 47 Cache storage Storage unit 4-1 Disk cache device 4-2
Disk cache device 43-1 Data transfer section 44-1 Cache control section 44-2 Cache control section

Claims (2)

[Claims] 1. In a disk cache device connected between a magnetic disk control device and a magnetic disk device, a cache control section that outputs update status information every time a cache memory section provided in advance is changed; a cache save control unit that receives update status information, temporarily stores the update information, and instructs to write the update information to a predetermined area of a pre-equipped magnetic disk device; a data transfer unit that receives the update information and outputs the update information to the area. 2. A disk cache device connected between a magnetic disk control device and a magnetic disk device, comprising a cache storage storage section, and updated information is stored in the cache every time a cache memory section provided in advance is updated. A disk cache device characterized by comprising a cache control unit that stores data in a storage storage part.