JPS62182955A - I/O failure recovery processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an input/output failure recovery system, and in particular to an input/output failure recovery system for reliably and quickly recovering when a media failure occurs in a direct access device in a computer system. This relates to a recovery processing method.

[Background of the invention]

In recent years, with the increase in the capacity of direct access devices such as magnetic disks, problems have arisen in terms of isolation and recovery time when failures occur.

Conventionally, when a failure occurs in a large-capacity direct access device, it has been common to unconditionally replace the device without attempting to isolate the failure. For this reason, in the past, data had to be checked after replacing the device, which resulted in an increase in failure recovery time.

Regarding this problem, there is a method described in, for example, Japanese Patent Laid-Open No. 10328/1983.

That is, this method is an excellent invention that, when a failure occurs in a direct access device such as a magnetic disk, saves time for diagnosis by determining whether the failure is in the device system or the media system.

However, this method is only concerned with a processing method that saves time and effort in isolating the faulty part, and does not take into account later data recovery time and effort.

[Purpose of the invention]

An object of the present invention is to improve such conventional problems, and after detecting a media system failure when a failure occurs in a direct access device, to recover only the data related to the failure, and to recover from the failure of the direct access device. An object of the present invention is to provide an input/output failure recovery processing method suitable for reducing time.

[Summary of the invention]

In order to achieve the above objects, the input/output failure recovery processing method of the present invention is applied to an electronic computer system comprising a processing unit, a direct access device such as a magnetic disk, and a data recovery device in the event of a media system failure of the direct access device. , a failure address information file for recording address information when a media system failure occurs in the direct access device, and an index file indicating in which area of the direct access device the recovery data should be stored, are provided; At the time of data recovery, the contents of the fault address information file and the index file are compared, and only the data related to the fault is transferred and recovered.

[Embodiments of the invention]

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

FIG. 1 is a system configuration diagram of an input/output failure recovery processing method showing an embodiment of the present invention.

In the figure, 10 is a processing unit, 20 is a magnetic disk device (hereinafter referred to as DK), 25 is a magnetic disk control device, 30 is a failure address information file that records failure addresses on the DK 20, and 40 is a storage for recovery data. a flexible disk device (hereinafter referred to as FD), 45 is a flexible disk control device, 50 is an index file that records in which area of the DK 20 the recovery data 51 should be stored, and 60 is a media system failure or device system failure when a failure occurs. The DK failure processing unit 7o, which detects the problem, transfers recovery data 51 stored in the FD to the DK2.
This is an FD/DK recovery processing unit that recovers data.

That is, the system to which the present invention is applied includes a processing device 1
0 is a computer system that accesses the magnetic disk device 20 via the magnetic disk control device 25, but in preparation for a media system failure, there is a DK failure processing unit 60 and an FD/DK internally installed.
This is an electronic computer system equipped with a recovery processing section 70.

Next, the failure recovery process according to the present invention will be overviewed with reference to FIG.

A fault address information file 30 for recording fault addresses is provided in the DK 20, which is a direct access device, and if it is determined that the fault is in the media system as a result of fault isolation, the DK fault processing unit 60 will detect the fault as shown in FIG. The faulty address is recorded in the address information file 30.

On the other hand, the recovery data is stored on the FD40, which is a recovery device, on the DK2.
An index file indicating which area of 0 should be stored is provided.

At the stage of failure recovery processing, the FD/DK recovery processing unit 70 reads failure address information before reading recovery data 51 from the FD 40, which is a recovery device.

Next, the FD/DK recovery processing unit 70 stores the contents of the index file 50 and the failed address information file 30.
, and only the data that needs to be recovered is transferred from the FD 40, which is a recovery device, to the DK 20, which is a direct access device.

In this way, the present invention aims to reduce the number of unnecessary reads/writes and shorten the recovery time.

FIG. 3 is a diagram showing the correspondence between the contents of the index area 50 of the FD and the DK data area 32.

The address in the DK data area 32 at which the recovery data 51 written on the FD should be stored is written in the index area 50.

That is, the index area 50 is used to indicate in which area of the data area 32 of the DK 2 the recovery data 51 in the FD 2 should be stored.

It is assumed that the first address and the last address in the data area 32 of the DK2 are those recorded in the index file 40 in the FD, and that the recovery data is written in the same format as the DK data area 32.

Note that for areas that do not require recovery from the FD, writing of the address of the recovery data area 51 may be omitted in the index file with only the address of the DK data area 32 (area C in the figure).

FIG. 4 is a diagram showing the processing flow of the F D/D K recovery processing unit 70 in PAD notation.

The processing operation will be explained below with reference to the same figure.

When a failure occurs in the DK 20, the DK failure processing unit 60
Isolate whether it is a media-related failure or a device-related failure. This D
Fault isolation by the K fault processing section 60 utilizes the input/output fault isolation processing method described in the aforementioned Japanese Patent Laid-Open Publication No. 10328/1983. That is, when a failure occurs, there is a method in which other subordinate magnetic disks are accessed, and if access is possible normally, it is determined to be a media system failure, and if access is not possible, it is determined to be a device system failure.

If the result of isolation is a device-related failure, the DK failure processing unit 6
0 indicates a control device replacement request.

In this case, if you do not accidentally replace the DK drive, the recovery time will not be a problem.

On the other hand, if it is a media-related failure, the DK failure processing unit 60
As shown in the figure, the faulty address is written in the faulty address information file 30, the system is stopped after the upper programmer or immediately, and the operator is requested to recover the DK data file 32.

When the operator sets the recovery FD 40 in the computer system, the FD/DK recovery processing unit 70 performs recovery processing in the order shown in FIG.

First, the FD/DK recovery processing unit 70 reads the failed address information file 30 in the DK and stores addresses that require recovery (step 4o1).

Next, the FD/DK recovery processing unit 70 determines the necessity of recovery processing based on the recovery data 51 written in the set recovery FD 40 based on the D data indicated by the index file 50.
Check whether the K address includes the faulty address stored in step 401 (steps 403, 405).
.

If it contains a failed address and requires recovery.

The FD/DK recovery processing unit 70 reads the FD recovery data 51 according to the contents of the index file, and then writes it to the DK (step 406).

If the fragrance is infused normally, the FD/DK recovery processing section 7
0 erases the recovered address on the failed address information file 30 (step 407).

If recovery is not necessary, advance one index file and repeat the same process for the next file (step 4).
08). The above operations are repeated until the processing of all recovery FDs is completed (steps 402 and 409).

In this way, according to this embodiment, unnecessary FD reading and FD writing can be avoided and recovery time can be shortened.

In this embodiment, the necessity of recovery is determined on a file-by-file basis, but if this is determined on a sector-by-sector basis, the recovery time can be further shortened.

Also, copy the index file 50 of the recovery FD to DK20.
By storing this information in the memory, not only can the upper programmer make a recovery request when a failure occurs, but it can also display which recovery floppy disk to prepare based on the failure address and the contents of the index file, and further reduce the recovery time. can be shortened.

〔Effect of the invention〕

As explained above, according to the present invention, in the media failure recovery process of a direct access device, only the necessary parts can be recovered without transferring unnecessary data, and the failure recovery time can be shortened. realizable.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram of input/output failure processing showing an embodiment of the present invention, Figure 2 is a structural diagram of the failure address information file of Figure 1, and Figure 3 is the FD/DK recovery process of Figure 1. The processing procedure of the section is shown in PAD notation. 10: Processing device, 20 2 Magnetic disk device (DK), 25: Magnetic disk control device, 3o: Fault address information file, 31: Maintenance area, 32: DK data area, 40: Flexible disk device (FD), 45: Flexible disk control device, 50: Index file, 51: Recovery data,
60: DK failure processing section; 70: FD/DK recovery processing section. Figure 1 Figure 2 Figure 3 Cow Figure

Claims (1)

[Claims] (1) In a computer system equipped with a processing unit, a direct access device such as a magnetic disk, and a data recovery device in the event of a media system failure of the direct access device, a fault is recorded in which a failure address is recorded when a media system failure occurs in the direct access device. An address information file and an index file indicating in which area of the direct access device the recovery data should be stored are provided, and when data is recovered after a media failure occurs in the direct access device, the failed address information file and the index file are stored. 1. An input/output failure recovery device that compares the contents of the data and transfers and recovers only the data related to the failure.