JPS5987572A - Controlling system of disk storage device - Google Patents

Abstract

PURPOSE:To make a special device and operation unnecessary, to save a time and to realize economization by securing only a data which requires a backup in an idle area on a disk, and transferring the data to other external storage device when no idle area exists. CONSTITUTION:A data is classified into that which requires a backup and that which does not require it, and as for that which requires a backup, a backup data address is placed in other table CL of the same line. Accordingly, it is unnecessary to provide separately an exclusive storage device for a backup.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a disk storage system, and more particularly to a method for preserving information stored in a disk storage device.

PRIOR ART As a means of ensuring the integrity of data stored on conventional disks or floppy disks, data may be transferred in bulk to magnetic tape or other disks or floppy disks, or transferred to other disks or disks with the same storage capacity. 70 discs are always operational, and each time a record write request occurs, records are written to two devices almost simultaneously, and when one device or medium becomes unusable, the other Two methods became mainstream: reading records from a disk device.However, the former method requires a magnetic tape device in addition to a disk device.
i, the cost is high and at the same time it is a certain time to obtain backup data.

The latter method has the disadvantage that it is cumbersome because it requires time and operations, and although the latter method is not cumbersome in terms of operation, it is expensive in that it requires two disk devices at all times. This was unavoidable, and especially for office computers, which are characterized by being cheap and convenient, it was a good idea to adopt either method.

OBJECTS OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks of the conventional technology by eliminating the need for special operations to obtain backup data, and eliminating the need for a dedicated file device for backup. Our goal is to provide a legal and highly reliable D&R storage device control method.

Summary of the Invention In order to achieve the above object #1, the present invention provides a disk recording
l Back up data corresponding to the data set allocated on the device medium! An information flag indicating whether or not the data set should be saved is provided, and the information flag is recorded on the data set label corresponding to the data set or on the memory device.
When a record is stored in a separate file installed on the computer and the information flag indicates that backup data should be acquired, if a record is written, the same record as the record is stored. It is characterized by automatically writing the contents into an area prepared separately from the data set area.

Examples of the invention An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

Figure 1 shows the main hardware configuration of an electronic computer to which the present invention is applied. There is a main control unit 1, a disk device 2, a connection cable 3, and a disk control device wire of the it ff machine, and the disk control device 4 is connected to the pass line 5.
The central processing unit 6 is connected to a storage device 7 via a path line 5, and the central processing unit 6 is connected to a disk by a program stored in the storage device 7. Controls the control device 4.

Figure 2 shows the disk mounted W! This is a description of the promised functions of data sets and data set labels placed and stored on the medium in 42. In this embodiment, the medium has track 8 from track address 0 to °C (n→-1).
It is constructed by arranging them in succession. Of these, track addresses 0 to m are called a data set label area 9, and track addresses m+1 to n are called a data set area 10. Each track 8 is equally divided into sectors 11, and the data set label area 9
The contents of any sector 11 within is called a data set label.

FIG. 3 shows an example of the promise function for each category in this data set label. One data set label consists of 256 bytes of information, including a backup data set presence/absence indicator 31, Column 32 indicating the data set name, Column 33 indicating BOE which is the first track address and sector address of the data set, EOF which is the last track sector address of the data set.
It includes a column 34 indicating J, a column 35 indicating the sector address EOD next to the end address where the record is actually stored in the p data set area, and a column 36 indicating the backup data set name.

FIG. 4 is a diagram showing the interrelationship between data sets for which backup data needs to be acquired, and address map data sets showing the positional relationships of the backup data sets and each of these data sets. The address map data set 46 has a fixed positional relationship on the disk by the data set label 45, and when the computer control unit 1 is in operation, the contents of the address map data set 4-6 are It is loaded and resident in one of the storage devices 7 together with the operating system.

The contents of the address map data set 46 are a table as shown in FIG.
L, a disk address table BL for the data set group that requires backup data acquisition, and a disk address table CL for the backup data set group, and is referenced by a disk driver that only controls the individual disks that have this table. Determine whether to acquire backup data. Table A column (AL
) indicates the disk address of a data set group for which backup data does not need to be acquired, and the start address of the data set is stored in the 51 part, and the final address is stored in the 52 part. Column 8 of the table (BL) shows the disk addresses of the data set group from which backup data needs to be obtained, and the first address of the data set is stored in the 53 part and the last address is stored in the 54 part. Column C (1) of the table is the disk address of the backup data set, which backs up the data set in column B shown in the same row as the backup data set in column C. The part 55 is the first address, and the part 56 is the last address.

In this way, by classifying data into those that require backup and those that do not, and for those that require backup, the backup data address is placed in a separate table on the same line. It is no longer necessary to provide a separate storage device.

FIG. 6 shows the relationship between the operating system and business programs loaded into the storage device 7.
Generally, there are many types of business programs, and when accessing a disk, the file management program 62 is started from the business program 61, and the file management program 6
2 converts it into physical access information such as the track address and selector address of the disk and sends it to the disk driver 6.
Start 3. The disk driver 63 resides in the storage device γ, and operates the disk unit N2 via the disk controller 4 under the action of the central processing unit 6.

FIG. 7 is an operational diagram of the disk allocator program.

Now, among the business programs 61, there is a business program called a disk allocator that has a function of allocating data files on a disk.

When this disk allocator is executed (701),
The operator determines for each data set whether or not that data set needs to be backed up (702).
. The subsequent operations are automatically performed by the business program (disc 0tator).

If it is determined that a backup is necessary, when allocating the data set 43, a flag indicating presence is set in the backup data set presence/absence indicator 31 in the data set label 41 (703).

Then, the backup data set name 36 in the data set label 41 is obtained (704). 5. Next, the backup data set 44 is allocated to an empty area on the disk (706). At this time, the previously acquired backup dataset name 36 is changed to the dataset label 4 of 44.
2 (705).

Furthermore, at this time, the address area information of the two allocated data sets 43 and 44 is stored in the address map data set 46 as a table (707).

The format of the table is as shown in FIG.

When the registration in this table is completed, the allocator stores the address map data set on the storage device 7.
o -do in a predetermined area (7
08).

This is the work of the disk allocator.

FIG. 8 is a processing flowchart of the business program.

When the disk driver 63 is started from a general business program or file management program 62, it is always given physical access address information on the disk.

If it is a write command, the given access address information is sent to fff, which is resident in the storage device 7.
Search on the address map table in Figure 5 (80
1).

Whether the address of the access information data is in column A or B
Determine whether it is from column C or from column C (80
2).

If the result of the determination is that the address belongs to column A, it is assumed that there is no need for backup, and the write command is executed as is (803).

If the address of the access information data belongs to column B, it is assumed that backup is necessary and the write command is executed as is (804), and then the address in the same row of column 0 corresponding to the access address of column B is written. 806) and write the same content to that address (1
30'7).

If the access address belongs to column 0, it is determined that this data cannot be written and the command is rejected (805).

In this way, the disk driver uses the address map table as a source of information on its activities and writes data to the disk while determining in real time whether or not it is necessary to obtain backup data.

Therefore, there is no need to randomly transfer and store all data stored on disks, floppy disks, etc. to other external storage devices, thereby improving storage efficiency for file storage.

Effects of the Invention As described above, according to the present invention, it is possible to determine the necessity of backup, secure only the data that needs to be backed up in an empty area on the disk, and if there is an empty area on the disk, If not, you can transfer the data to another external storage device for the first time, so there is no need to perform any special operations to obtain backup data, and there is no need for a dedicated file device for backup. It is possible to preserve information stored on a disk or floppy disk by simply securing a backup data set on the same medium on which the data is stored or on a storage medium in a separate device. This saves time and is also economical.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the hardware configuration of an electronic meter to which the present invention is applied, FIG. 2 is a diagram showing the address arrangement of data on a disk showing an embodiment of the present invention, and FIG. The figure shows the role of each column in the dataset label in an embodiment of the present invention, and Figure 4 shows the data sets that require backup dataset F and their backup in an embodiment of the present invention. FIG. 5 is a diagram showing the structure of the address map data set in one embodiment of the present invention. FIG. FIG. 7 is a flowchart of processing when executing a disk allocator program in an embodiment of the present invention. FIG. A8 is a flowchart of processing according to an embodiment of the present invention when executing a business program according to an embodiment of the present invention. 2: Auxiliary storage device, 9: Data set label area, 10
: Data set area, 31: Backup data set presence/absence indicator, 32: Data set name, 36: Backup data set name, A L: Backup unnecessary data table, BI: Backup required data table, C
L: Backup data table. Patent applicant Hitachi Seisakusho New Building 1 Figure 2 Figure 4. Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] In a control method for a disk storage device, an information flag indicating whether or not data in the data set should be saved is provided for each data set allocated on the medium of the disk storage device, and the information flag is set to correspond to the data set allocated to the medium of the disk storage device. A record is stored on the data set label corresponding to the data set or in a recording area other than that label, and the record is stored in the data set with the flag indicating that 4 data in the data set should be left. When a write operation is performed, the same content as the record is written in an area other than the data nut area.