JPS61109160A - Area control system for inter-system share volume - Google Patents

Abstract

PURPOSE:To shorten the replacement processing time of a volume register list VTOC by giving just a reserved display on the VTOC with a temporary work file and performing the registration when necessary with an inherent or shared file. CONSTITUTION:An area set under an idle mode 1 is changed to an allotment executed mode 2 in the form of an inter-system share file by the file area allotment processing. The undesired shared file is reset to the mode 1 by the file release processing. At the same time, the area set under the mode 1 is turned into a reserved mode 3 to either one of systems by the collective reservation process. The area in the mode 3 can be canceled (released collectively) with its reservation. It is also possible to turn an area used as a work file in the system reserved area into a system proper area. Then this inherent area is turned into an allotment executed mode 4 by the partial allotment processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an area management system for an external storage device for a computer, a so-called direct access storage device (DASD), and particularly for a DASD that is shared by two or more computer systems. The present invention relates to a method for efficiently allocating/releasing a work file area used only within one system.

[Conventional technology]

Generally, the management of file areas on a DASD is
Using the volume register (VTOC) in a specific area in D, the hardware on the DASD side allocates/releases the area.

Furthermore, when a DASD (or more accurately, a volume: one DASD includes one volume or a plurality of volumes) is shared between a plurality of systems λ, some kind of inter-system exclusive control is required for area management reasons.

The shared volume includes a shared file whose contents are shared by both systems, a unique file used uniquely by one system, and a work file used temporarily as a work area by one system.

In conventional area management using VTOC, areas on a volume are managed by classifying them into "allocated areas" and "free areas."

[Problem that the invention seeks to solve]

In conventional area management methods, exclusive control is performed on the VTOC with the same treatment when allocating the above-mentioned unique file or the above-mentioned work file to one system, and in order to do so, it is necessary to access the VTOC many times. During this period, other systems will be unable to access the volume.

In this type of system, the number of conversational terminals is increasing.
It is inefficient when temporary work areas are frequently created and deleted for each request source such as each terminal, such as in a computer-oriented system.

[Means for solving problems]

The purpose of the present invention is to improve the efficiency of temporary work area allocation/release processing, and for this purpose, VTO
In addition to “allocated” and “free”, space management on C can be changed to “allocated” and “free”.
This is done using three types of status: ``reserved''.

[Effect]

That is, each system simply reserves a predetermined area in advance, and
The TOC simply indicates that the area is reserved, and only prevents other systems from making duplicate reservations, and the assignment of work files to each terminal within the area is at the discretion of the system in question. Since the area management program independently manages the memory, the complicated processing associated with formal VTOC allocation work is unnecessary, and access by other systems is not delayed.

If you want to officially make one of the work files a shared file or a fixed file as a storage file, you can register it in the VTOC at that point.

〔Example〕

FIG. 1 is a state transition diagram of the area management system according to the present invention. Free status (The area in 11 is allocated as an inter-system shared file by file area allocation processing) (
2). A shared file that is no longer needed returns to the free state ill through file release processing. Another vacancy! 3t
The area at t+ becomes reserved for any one system (3) through the batch reservation process. The system reserved area can also be released (released all at once).

Each system can freely use the area reserved by the system. The area used as a work file in the system reserved area can also be made into a system specific area, and the area becomes allocated state (4) through partial allocation processing. Of course, the area can also be partially released.

FIG. 2 is a diagram showing the schematic structure of a VTOC and its correspondence with each IN area within a volume in an embodiment of the present invention, and the volume control block (VCB) divides the volume into predetermined unit sizes. , each has been assigned (A
), vacant (F), or reserved (R). The file allocation block (FEB) includes the name of each file, the name of the system to which it is allocated, the mode of exclusive control,
It holds the address, area size, etc. on the volume. A free space control block (FSB) holds information such as the size of free space and addresses on the volume. The reserved space control blocks (R3B1, R3B2) hold the reserved system name, size, volume address, etc. of the area reserved for each system.

〔Effect of the invention〕

As described above, according to the present invention, a temporary work file is only displayed as a reserved file on the VTOC, and is registered as a unique file or a shared file when the need arises. The update processing time can be shortened, the access prohibition time for other systems can be shortened, and even in a large-scale online system, efficient DASD area management is possible.

[Brief explanation of drawings]

FIG. 1 is a state transition diagram of the area management method according to the present invention, and FIG.
The figure is a diagram showing a schematic structure of a VTOC and its correspondence with areas within a volume in an embodiment of the present invention.

Claims (1)

[Claims] The volume register (VTO) manages the area allocation status.
C), in which the allocation status of the above-mentioned areas is defined as free status, allocated status, and reserved status, and areas in the reserved status are subject to applicable conditions. An area management control method for an inter-system shared volume, characterized in that an area management program of a system that has reserved an area controls allocation of work files to each request source in the system.