JPH04102135A - File duplication control system - Google Patents

Abstract

PURPOSE:To improve efficiency for utilizing resources by deciding a magnetic disk device as a main system and a system to execute an input / output among extended storage devices as a sub system corresponding to the states of the respective systems. CONSTITUTION:A file system control means 1 controls the position of storing a file data in a magnetic disk device 9 and a duplex mode, and a file block control means 2 controls data transfer for the unit of a block. Then, a duplex control means 3 decides the magnetic disk device 9 as the main system and the system to execute the input / output among extended storage devices 10 as the sub system corresponding to the states of the respective systems and controls the position of storing the file data in the extended storage device 10. When the fault of the master system is reported, it is recorded and when a recovery request is received, the data phase is executed from the sub system to the master system. Then, a magnetic disk control means 4 controls the magnetic disk device 9 and reports the fault when the data can not be transferred, a sub system storage control means 5 controls idle blocks in the extended storage device 10, and an extended storage control means 6 controls the extended storage device 10. Thus, efficiency is improved for utilizing resources.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file duplication control method in a computer system.

[Conventional technology]

In order to protect file data of a file system constructed on a magnetic disk device from unexpected failures of the magnetic disk device, a method called duplexing is generally adopted.

In other words, there are two systems of magnetic disk drives, a primary system and a secondary system, and output (writing) is performed to both systems (primary system and secondary system), and input (reading) is performed from one system (primary system or secondary system). If a fault occurs in one system and it is determined that data transfer is impossible, the faulty system is shut down and input/output continues on the other system. Then, in response to a request from a user, recovery is performed by copying file data from the normal system to the failed system.

[Problem to be solved by the invention]

As mentioned above, the conventional file duplication method was able to guarantee file data against unexpected failures of magnetic disk devices, but since two systems of magnetic disk devices were provided, it had the following drawbacks. .

- Double the number of magnetic disk devices is required for duplication, which requires a large storage space and is inefficient in resource utilization.

■When writing, it is necessary to write to two systems of magnetic disk devices, so the processing takes time.

The present invention has been proposed in view of the above points, and its purpose is to provide a file that can improve the resource usage efficiency and perform high-speed input/output processing without compromising the guarantee of file data through duplication. The objective is to provide a redundant control method.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a file system control means for managing file data storage position 1 and duplex mode in a magnetic disk device, and control of data transfer in units of blocks. A file block control means that determines which system performs input/output among the magnetic disk device as the main system and the expanded storage device as the secondary system according to the state of each prefecture, and also controls the storage of file data in the expanded storage device. A redundancy control means that manages the location of the main system, records the fact when it receives a failure notification of the main system, and transfers data from the subsystem to the main system when a recovery request is received; A magnetic disk control means that performs control and notifies a failure when data transfer is impossible; A sub-system storage control means that manages free blocks in the expanded storage device; and an expanded storage control means that controls the expanded storage device. I am trying to prepare for this.

Here, the expanded storage device is a large-capacity semiconductor storage device that can output data as quickly as the main storage device without using a channel device.

[Effect]

In the file duplication control method of the present invention, the file system control means manages the storage location of file data in the magnetic disk device and the duplication mode, and the file block control means controls data transfer in units of blocks, The control means determines which system performs input/output among the magnetic disk device as the main system and the expanded storage device as the subsystem according to the state of each prefecture, and also manages the storage location of file data in the expanded storage device. ,
When receiving a fault notification on the main system, record the fact, and when a recovery request is received, data is transferred from the sub system to the main system.
The magnetic disk control means controls the magnetic disk device and notifies the failure when data transfer is impossible, the sub-system storage control means manages free blocks in the expanded storage device, etc., and the expanded storage control means controls the expanded storage device. control.

C Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the file duplication control method of the present invention.

In FIG. 1, this embodiment includes a file system control means 1, a file block control means 2, and a duplication control means 3.
, a magnetic disk control means 4 , a subsystem storage control means 5 , an extended storage control means 6 , a duplication management table 7 , a user buffer 8 , a magnetic disk device 9 , and an extended storage device 10 .

The functions of each part are outlined below.

User buffer 8: A storage area on the main storage device (not shown) allocated to the user program, in which file data to be written to the magnetic disk device 9 is written in advance, and file data read from the magnetic disk device W9. It is used to temporarily store.

Magnetic disk unit I19: This is an external storage device that constitutes a primary storage device and on which a file system is constructed.

Magnetic disk control means 4; controls the magnetic disk device f9, and also serves as duplex control means 3 when data cannot be transferred.
This is the part that notifies you of a failure.

Expansion storage device 10: This is a large-capacity semiconductor storage device that constitutes a sub-system storage device and can input and output data at high speed like the main storage device without going through a channel device.

Extended storage control means 6: This is a part that controls the extended storage device 10.

File system control means 1: This is a part that manages the storage position of file data in the magnetic disk device 9 and the duplication mode.

File block control means 2: This is a part that controls data transfer in block units.

Redundancy control means 3; determines the system that performs human output among the magnetic disk device 9 as the main system and the expanded storage device fIO as the secondary system according to the state of each prefecture, and stores file data in the expanded storage device 10. This is a part that manages the location, records the fact when receiving a fault notification from the magnetic disk control means 4 in the main system, and causes data to be transferred from the sub system to the main system when a recovery request is received. .

Duplex management table 7: This is a table that stores management information necessary for the duplex control means 3, as shown in FIG.
Each of the file systems built on the magnetic disk devices (9A, 9B) has a status flag indicating whether it is in a normal state or a blocked state, a disk device number that specifies the magnetic disk device in which that file system exists, and its It manages a logical block number indicating the storage position in the magnetic disk device and an extended storage block number indicating the storage position in the extended storage device 10 of the same file system.

Sub-system storage control means 5: This is a part that manages empty blocks in the expanded storage device 0.

Hereinafter, the operation of the above embodiment will be explained for each case.

(1) When writing normal file data, a user program (not shown) etc. specifies the user buffer 8 and writes its contents (file data) to a predetermined file in the file system on the magnetic disk device 9. request something.

The file system control means 1 checks on which logical block in the file system the file data of the file is located and whether or not the file is opened for duplication mode by referring to the management information. do.

If the logical block is found and the mode is duplication, the file system control means 1 requests the file block control means 2 to write file data one block at a time. Note that the case where the mode is not duplex is not covered by the present invention, and therefore the explanation will be omitted.

When the file block control means 2 receives a write request from the file system control means 1, it notifies the duplication control means 3 of the logical block number and the device number where the target file system exists.

The duplexing control means 3 refers to the duplexing management table 7 and confirms that both the main system (magnetic disk device t9) and the subsystem (extended storage device ffO) are normal.

If both systems are normal, the notified magnetic disk device 9
The magnetic disk control means 4 is asynchronously requested to write the contents of the user buffer 8 to the logical block number.

The magnetic disk control means 4 issues a write command to the magnetic disk device f9.

On the other hand, the duplexing control means 3 refers to the duplexing management table 7, determines which block number the notified logical block number is located in the subsystem, and the subsystem storage control means 3
Notify the block number to

The sub-system storage control means 5 requests the extended storage control means 6 to write the contents of the user buffer 8 to the received block number in the extended storage device 10.

The extended storage control means 6 controls the extended storage device 10 to write file data in a synchronous manner.

Note that if this write process requires securing a new file block, one free block on the expanded storage device 10 managed by the secondary storage control means 5 will be secured for that block.

After confirming the completion of writing in the extended storage device 10, the duplication control means 3 waits for the completion of writing in the magnetic disk device 9.

(2) When reading normal file data A user program (not shown) requests that the contents (file data) of a predetermined file in the file system on the magnetic disk device 9 be read into the user buffer 8 .

The file system control means 1 confirms on which logical block in the file system the file data of the file is located by referring to the management information, and requests the file block control means 2 to read the file data. do.

When the file block control means 2 receives a read request from the file system control means 1, it notifies the duplication control means 3 of the logical block number and the device number where the target file system exists.

The duplexing control means 3 acquires the block number of the subsystem from the duplexing management table 7 based on the block number taken by the receiver,
The sub-system storage control means 5 is requested to read.

The sub-system storage control means 5 requests the extended storage control means 6 to read.

The extended storage control means 6 controls reading of file data from the extended storage device 10 and stores the read file data in the user buffer 8.

Therefore, input processing to the main system does not occur.

(3) When a failure occurs, the magnetic disk control means 4 is the magnetic disk device 9 on the primary side.
If it is determined that manual output of data is no longer possible due to some device failure, it notifies the duplication control means 3 that the corresponding magnetic disk device 9 will be blocked.

When the duplexing control means 3 receives the notification, it turns on the status flags corresponding to all blocks of the blocked magnetic disk device in the duplexing management table 7.

As a result, no output (writing) is performed to the magnetic disk device, that is, the main system, and all output processing is performed only in the sub system.

(4) At the time of recovery, when the user unblocks the device, the duplex control means 3
request for recovery of the main system.

The duplexing l111 means 3 searches for blocks whose status flags are on in the duplexing management table 7, and sequentially transfers the blocks from the extended storage device 10 to the normal magnetic disk device 9.
The main file system is restored by transferring the file data.

(5) At system termination, etc. The contents of the duplication management table 7 are written to the extended storage device 10 when the system is terminated, and are expanded onto the main storage device again during the next operation, thereby guaranteeing the subsystem data.

〔Effect of the invention〕

As explained above, in the file duplication control method of the present invention, the extended storage device is allocated only during system operation like the main storage device, and does not always occupy the file area, so the magnetic disk device Resource usage efficiency is improved without causing an increase in the above file area.

(2) Since writing to the extended storage device can be performed at extremely high speed, the time required for writing is approximately only for one system of the magnetic disk device, and processing time can be shortened.

■Since reading can be performed directly from the extended storage device, processing is extremely fast.

There are other effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the file duplication control system of the present invention, and FIG. 2 is an explanatory diagram of the duplication management table in FIG. 1. In the figure,

Claims (2)

[Claims] (1) A file system control means that manages the storage location and duplex mode of file data in a magnetic disk device, a file block control means that controls data transfer in blocks, and a magnetic disk device as a main system and a subsystem. In addition to determining the system that performs input/output among the extended storage systems as a main system, it also manages the storage location of file data in the extended storage system, and informs the system when a fault notification is received from the main system. a duplex control means that records data and transfers data from the subsystem to the main system when a recovery request is received; and a magnetic disk control means that controls the magnetic disk device and notifies a failure when data cannot be transferred. A file duplication control method comprising: a secondary storage control means for managing free blocks in an expanded storage device; and an expanded storage control means for controlling the expanded storage device. (2) The file duplication control system according to claim 1, wherein the duplication control means performs control based on information in a duplication management table.