JPS63173270A - Data set area managing system for draw type storage device - Google Patents

Abstract

PURPOSE:To prevent a useless unused area from being left in a data set even when the data quantity cannot be grasped in advance, by generating a data in the data set on a DRAW type storage medium, and thereafter, releasing an unused area. CONSTITUTION:A data is written in an area 14 which is assigned as a data set, and when an unused area has been left, its size is derived by referring to position information of a data set management label 13 at the time of assigning the data set area 14 obtained by follow-up the data set management label 13 provided newly and a chain address 17 of the management label. In such a way, even in case of an area which is assigned as a data set once, since an unused area in which a data is not written is released, and can be reutilized for other data set, thereby the area can be used efficiently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a write-once storage device such as an optical disk device that cannot be rewritten, and in particular, the present invention relates to a write-once storage device such as an optical disk device that cannot be rewritten. This invention relates to an area management method suitable for reusing the unused area as another data set.

[Conventional technology]

In recent years, optical disks have been attracting attention as a compact, large-capacity storage medium. However, since write-once optical disk storage devices are not rewritable, the data section is generally stored on the optical disk, and the information that manages the position information of the data section is stored on a rewritable recording medium separate from the optical disk. A method is used to store the information in A related example of this type of write-once type optical disk storage device is, for example, Japanese Patent Laid-Open No. 142656/1983.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, since the data section and the control information are stored on separate media, there is a problem in terms of portability, which is one of the characteristics of optical discs.

A possible solution to this problem is to allocate one or more data set areas on the optical disk in advance and store information for managing them on the same optical disk. However, since the data set area on the optical disk cannot be allocated incrementally, a larger amount is allocated, leaving an unused area within one data set area.

On write-once optical discs, the information that manages data set location information cannot be rewritten, so even if there is unused space left in the allocated area, that unused space cannot be reused by setting another data. Therefore, optical discs cannot be used effectively.

SUMMARY OF THE INVENTION An object of the present invention is to provide an area management system that allows efficient use of a data set area on a write-once storage device without placing any burden on the user.

[Means for Solving the Problems] The present invention sets a new dataset management label corresponding to the data writing area when writing of data in the allocated dataset area is completed, and sets a new dataset management label in the dataset management label. Dataset management label when allocating dataset space.

(current data set management label) and deletes the current data set management label.

[For production]

If data is written to the area allocated as a dataset and an unused area remains, its size can be determined by tracing the newly established dataset management label and the chain address of the management label at the time of dataset area allocation. Determined by referring to the position information of the dataset management label. As a result, even if the area is once allocated as a data set, unused areas where no data is written can be released and reused for another data set, allowing for efficient use of space. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the logical structure of an optical disk volume when the present invention is applied to an optical disk as an embodiment. The optical disk volume 11 is divided into a volume label area 12 for identifying the volume, a data set management label area 13 for managing data sets, and a data set area 14 for storing data. The volume label area 12 stores a volume label (VOLI) 12-a that identifies the volume. The dataset area 14 is allocated to each independent dataset 14-a, 14-b, . It is managed by...

Each data set management label stores management information such as the name of the header data set and position information that is 1 when the data set is assigned.

When storing data on an optical disk, after allocating a data set on the optical disk and securing a data set area, input (write) the data using a user program, etc.
do. In the present invention, when this data input is completed, that is, when the CLO8E macro is issued from a user program, etc., the system program releases the unused area in the dataset, and the unused area is transferred to another dataset. It is intended to be reusable for other purposes.

In FIG. 1, data set A and data set B have already been allocated as 14-a and 14-b on the data set area 14 of the optical disk volume 11,
When creating a new dataset C, the free area 14-c is allocated as the area for the dataset C, and a management label (hereinafter referred to as HD
13-c (referred to as R1 label) is created. This HDRI
The addresses of P5 and P6 are temporarily stored in the label 13-G as the data set positions. Data is sequentially input into the data set area 14-c allocated in this way by a user program, etc., starting from position P5, which is the head of the data set area 14-c, and data is input at position P7. When completed, the CLO8E macro is issued. Therefore, at this point, the part indicated by 15 in the data set area 14-c has been populated with data and is an area that cannot be reused, but the part indicated by 16 is an area in which data has not been input and can be used in another dataset. This is an area that can be reused. Therefore, when the CLO8E macro is issued, the system program
c is updated, and the unused area 16 in the data set area 14-C is released.

Figure 2 shows the procedure for this update process, which is only performed when it is being processed in the output system (step 100).
, to rewrite the HDRI label 13-C, make the data input range (from P5 to P7) a new data set area, and store the chain address 17 of the current HDRI label 13-c to create a new HDR1 label 13-x. Re-create the current HDRI label (step 110), the current HDRI label 13-
By deleting C (step 120), the unused area 16 of the data set area 14-C is released. As a result, among the deleted HDRI labels 13-c, subsequent HDRI labels 13-x are used.

Only the area managed by the HDR1 label that is chained can be considered as an unused area, and can be reused for another data set. It should be noted that, for example, each management label 13-a of the dataset management label area 13 is deleted.

13-b, . . . by providing a deletion indication bit at the beginning and fixing this bit to 111 I+ 6 Figure 3 shows H
This shows the specific format of the DRI label, which allows the data set area 14-c as shown in FIG.
We will explain how the contents of the HDRI label change when the unused area is released after data is allocated and the unused area is released.

In addition, PBN in FIG. 3 is a physical block number, which is a block number based on the first block of the optical disk volume 11, and LBN is a logical block number, which is a block number based on the first block of the corresponding data set. It means.

In the HDR1 label 13-c created when the dataset area 14-c in FIG. 1 was allocated, as shown in FIG. is P6, the start LBN33-c of the data section is 0, the end LBN34-c of the data section is P6-P5, the final LBN35-c of the recording data,
The PBN 17-c of the HDRI at the time of initial allocation is not set. Furthermore, extent allocation attribute 36-C
is set with a code indicating that it was allocated with all allocation specification. That is, at this point, there is apparently no unallocated area in the data set area 14 of the optical disk volume 11 shown in FIG.

When data is input into this data set area 14-c,
P5, which is the first block of the data section indicated by 33-c.
Write data sequentially from When the data up to the block indicated by P7 is written and the CLO8E macro is issued, the extent allocation attribute 36-c is a code indicating all allocation designation, so in order to release the unused portion 16, a new HDR1 label 13- is written. Create x. HD
Data set start PBN3゜1- for R1 label 13-x
x, and the start of the data section L B N 33- x is H
31-c, 3 set to D R1 label 13-C
Same value as 3-c, but end of data set PBN3
2-x is P7, data section end LBN34-x is P7-
P5, extent allocation attribute 36-x sets a code indicating normal allocation. Furthermore, the final LBN35-x of the recording data is set to P7-P5 in the same way as 34-x, and the PBN17-x of the HDR1 label at the time of initial allocation is
Set I(physical block number of DRI label 13-c. In other words, this means that you have created HDR1 label 13-x that manages only the part where data is written. After that, HDR1 label 13-C Delete.

When referring to the data of dataset C, the HDR1 label 13-c is a deleted block, so the HDR1 label of dataset C is 13-x, and the dataset area is in the range from P5 to P7. Also, when allocating further data sets to this volume 11, H
DRI labels are sequentially analyzed including deleted blocks to create an area map of the assigned data set.

When analyzing up to HDRI label 13-c, the area of dataset C is from P5 to P6, and there is no unallocated area, but when analyzing HDR1 label 13-x, chain address 17-x is changed to HDR1 label 13-x. Since it points to data set C, the area of data set C is changed to the range from P5 to P7. Therefore, the range from the block next to P7 to P6 can be allocated to a new data set as an unallocated area.

〔Effect of the invention〕

According to the present invention, unused areas can be released after data is created in a dataset on a write-once storage medium, so even if the amount of data cannot be known in advance, there is no need to leave unnecessary unused areas in the dataset. This has the effect of making it possible to use the area on the medium efficiently without wasting it.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the logical configuration of an optical disk volume to which the present invention is applied, Figure 2 is a diagram showing the procedure for updating the dataset management label in Figure 1, and Figure 3 is the format of the dataset management label. It is a figure which shows an example. 11... Optical disk volume, 12... Volume label, 13... Data set management label, 14... Data set area, 15... Data input area, 16... Unused area, 17. ...Chain address. Figure 1

Claims (1)

[Claims] (1) In a write-once storage device equipped with a dataset area allocated in advance for storing datasets and an area for storing information for managing the dataset area (hereinafter referred to as dataset management label), the allocated When data is written to the dataset area and an unused area remains, a new dataset management label (hereinafter referred to as the first dataset management label) corresponding to the data writing area in the dataset area is set, and the setting In the first dataset management label that has been assigned, a dataset management label (
A data set area management method characterized by storing a chain address of a second data set management label (hereinafter referred to as a second data set management label) and deleting the second data set management label.