JPS6374170A - Control system for magnetic disk - Google Patents

Abstract

PURPOSE:To perform a copying action at a high speed when a fault of a duplex file is restored by copying the contents of a magnetic disk device designated by the stored write address information to another magnetic disk device that restored the fault. CONSTITUTION:A magnetic disk device to be paired with another magnetic disk device 5 to be written double is separated from a system owing to a fault and then incorporated again to the system after the fault is recovered. Thus an under-copying indication is given to a disk controller 1 from a host for the device 5 via an interface line 11. Then the host reads data out of the device 5 and copies them to the magnetic disk device after its fault is recovered. If a write indication is received from the host to the device 5 during a copying action, the relevant address is stored in a rewrite address memory 4. When a reading action is through to the device 5 for copying, the address stored in the memory 4 is read out through the device 5 and copies to the magnetic disk device after its fault is recovered.

Description

TECHNICAL FIELD The present invention relates to a magnetic disk control system, and more particularly to a magnetic disk control system in a dual file system that performs full file copying using software.

BACKGROUND ART Conventionally, in this type of duplex file system, when recovering from a failure of a duplex file, software prohibits writing to the file until the copy is completed, and the entire file is copied.

In conventional duplex file systems like this, while the entire file is being copied, the software prohibits writing to the file, so any write access to the file during that time is forced to wait. , which results in a significant response delay for the job.
There was a drawback.

In addition, if a file is shared by multiple CPUs (central processing units), there will be many complicated processes such as reporting between CPUs to notify that write access to the file is prohibited, and the entire system will be The disadvantage was that it caused a significant decrease in throughput.

Purpose of the Invention The present invention has been made to eliminate the drawbacks of the conventional methods as described above, and is capable of speeding up the copying operation when recovering a duplexed file from a failure, and eliminating the need to wait for write access during the copying operation. The purpose of the present invention is to provide a magnetic disk control method that can improve the throughput of the entire system.

Composition of the Invention The magnetic disk control method according to the present invention is a magnetic disk control method for a duplexed file system in which a file is copied by software from a magnetic disk device to a magnetic disk device that performed failure recovery when a duplexed file is recovered from a failure. , a storage means is provided for storing write address information when a write instruction is given from a host device to the magnetic disk device during the copying, and the address information specified by the write address information stored in the storage means after the copying is completed is provided. The present invention is characterized in that the contents of the magnetic disk device are copied to the magnetic disk device in which the failure recovery has been performed.

1 Yutaka 3 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, one embodiment of the present invention includes a disk control device 1, a control unit 2, a copying indicator 3 indicating that a dual-write magnetic disk device 5 is in the process of copying, and When there is a write access to the magnetic disk device 5 being executed, there is a rewrite address memory 4 that stores the address (cylinder number, track number) at which the write operation was performed, and a rewrite address memory 4 that is subject to double writing by software. A host interface line 11 that transfers various commands, data, status, etc. between a host (not shown) and the disk control device 1, and a magnetic disk device 5 and the disk control device 1. It is comprised of a device interface line 12 between which transfers various commands, data, status, and the like.

When a magnetic disk device (not shown) paired with the magnetic disk device 5 to be dual-written by software is disconnected from the system due to a failure and is incorporated into the system after recovery from the failure, the host controls the disk via the host interface line 11. A copying instruction to the magnetic disk device 5 is issued to the device 1.

In response to this instruction, the disk control device 1 uses the control unit 2 to turn on the copying indicator 3.

Thereafter, the host uses software to perform a copy operation of reading data from the magnetic disk device 5 and writing the read data to the magnetic disk device after the failure has been recovered. This copy operation is performed without disconnecting the magnetic disk device 5 from the system.

During this copy operation, when the host issues an instruction to the disk-based tII device 1 to write to the magnetic disk device 5 via the host interface 11, the control unit 2 receives the address (cylinder number, track number) where the write instruction was made. ) is stored in the rewrite address memory 4.

When the read operation for copying to the magnetic disk device 5 is completed, the software checks the contents of the rewrite address memory 4, and if the address where the damage was done to the magnetic disk device 5 during the copy operation is registered, The contents of that address are read again from the magnetic disk device 5 and copied to the magnetic disk device after the failure has been recovered.

In this way, during a copy operation from the magnetic disk device 5 to the magnetic disk device after recovery from a failure, a write instruction is sent from the host to the magnetic disk device 5, and the write address at which the write operation was performed is rewritten to the address memory 4. After the copy is completed, the software rewrites the magnetic disk drive d5 corresponding to the special address stored in the address memory 4 via the host interface line 11.
By copying the data to the magnetic disk device after recovery from a failure, it is possible to speed up the copy operation when recovering a duplex file from a failure, and it is also possible to eliminate the waiting period for write access during copy operation. , the throughput of the entire system can be improved.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when a write instruction is received from a host device to a magnetic disk device while a full copy is being performed from a magnetic disk device to a magnetic disk device that has been recovered from a failure, , the write address information for which the write operation was performed according to the write instruction is stored, and after the copy is completed, the contents of the magnetic disk device corresponding to the stored write address information are copied to the magnetic disk device that has been recovered from the failure. By doing so, it is possible to speed up the copy operation when recovering a duplicated file from an IJ damage, eliminate the waiting period for write access during a copy operation, and improve the throughput of the entire system. effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. Explanation of symbols of main parts 2...Control unit

Claims (1)

[Claims] A magnetic disk control method for a duplex file system in which a file is copied by software from a magnetic disk device to a magnetic disk device that performed failure recovery when a duplex file is recovered from a failure, and the method includes writing from a host device to the magnetic disk device at the time of copying. A storage means is provided for storing write address information when an instruction is given, and after the copying is completed, the contents of the magnetic disk device designated by the write address information stored in the storage means are stored in a magnetic disk drive that performs the failure recovery. A magnetic disk control method characterized by copying to a disk device.