JPH0484341A - File storing system - Google Patents

Abstract

PURPOSE:To allow a user to have a file space larger than an actually used preserving storage device so as to reduce the storing area managing burden on the user by only performing writing in a block where effective information exists at the time of initializing a file. CONSTITUTION:A conversion table 1 which is used for converting logical addresses into real addresses and contains information for discriminating whether or not a real storing area is unassigned in corresponding to a logical address, and a management table 2 which manages vacant real storing areas are provided. When an access request is accepted, the table is searched for discriminating whether or not a real storing area is unassigned is made based on the discriminated information at the corresponding entry of the logical address and, when the area is unassigned, the access is made after a vacant real storing area is assigned on the table 2 and, at the same time, the tables 1 and 2 are preserved in storing areas 33 and 34 of another fault unit which are different from their original preserving areas. By providing a file storing space which is assigned upon accepting an access request to a real storing area in such way, the storing area can be used efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a file storage method in an information processing system.

[Conventional technology]

The storage area of a computer system is roughly divided into two types: main storage and secondary storage (external storage such as a magnetic disk device). Of these, the latter secondary storage is generally divided into spaces called files or data sets and managed. Conventionally,
This divided storage space (file) is defined by the user as a space with consecutive addresses, and a method has emerged in which it is accessed using an address mechanism similar to main memory, but the space defined as a file space For tooth extraction, a real memory area is allocated without a part.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, if a spare address space is secured internally in consideration of future data addition, the real space is also secured at the same time, so there is a problem in that the storage device cannot be used effectively. Another problem is that when a partial failure occurs in a storage area, the logical address of the corresponding file is not known, and even if a spare storage area is allocated, only the partial information cannot be recovered.

An object of the present invention is to solve such problems and to provide a file storage space in which real storage is allocated at the time of an access request, thereby enabling efficient use of storage.

[Means to solve the problem]

In order to achieve the above object, the invention of claim (1):
It has information for determining whether or not a real memory is attached to a logical address, a conversion table from a logical address to a real address, and a management table for managing free real storage area, and when an access request is received, the above-mentioned The conversion table is searched and it is determined whether the logical address is unallocated or not based on the judgment information of the corresponding entry, and if it is unallocated, free real memory is sometimes allocated using the management table before access is made. A feature of this method is that the management table is stored in a storage area for each failure that is separate from the location where the management table exists.

Further, claim (2) is characterized in that it includes a conversion mechanism for determining a file and its logical address from a real address.

[For production]

When an access request is received, the judgment information of the corresponding entry of the corresponding logical address in the conversion table is checked, and whether it is already allocated (valid) is checked.
If so, input/output to secondary storage is performed using the real address of the entry. On the other hand, if it is unallocated (invalid), it is checked whether the access request is an input request or an output request, and the input/output of the input request is performed. If this is the case, the end is processed without doing anything (handled as normal or abnormal), but if it is an output request, real storage is allocated to the block with reference to the management table and the secondary storage is accessed.

The conversion table and the management table are saved in a storage area for each failure that is different from their normal location, and the recorded information and the saved conversion table are used as a save file.

〔Example〕

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

Figure 1 shows a fixed size for logical addresses (called blocks).
FIG. 2 is a conceptual diagram of an embodiment of the present invention in which real storage is allocated as a unit. In Figure 1, 1 is an address conversion table that converts logical addresses to real addresses (in this case, from logical block numbers to real block numbers), 2 is a free real storage management table that manages free real storage areas, and 3 is a magnetic A secondary storage device such as a disk device. The secondary storage device 3 is provided with storage areas 33 and 34 for the address conversion table 1 and the real storage management table 2. 4 is an access mechanism that processes access requests, and includes a real memory allocation mechanism 40.

5 has a table storage mechanism that stores the address translation table 1 and free real storage management table 2 in the secondary storage device 3. Address conversion table 1
has a field 12 for storing a real address in an entry 11 corresponding to a logical address, and a flag section 13 for indicating whether or not the field is valid. Of course, it is also easy to make the allocation unit (block size and real block address structure) variable depending on the configuration of the conversion table. The address conversion table 1 and the free real storage area table 2 can be implemented in the main memory or in a storage storage control device such as a magnetic disk.

FIG. 2 shows the processing flow of the access mechanism 4. When an access request is received, the address conversion table 1 is searched (step 101), and the flag section 13 of the corresponding entry 11 of the corresponding logical address is checked (step 102).
), if valid, input/output to the secondary storage device 3 is performed using the real address in the field 12 (step 103,
108).

If the flag section 13 of the corresponding entry 11 is invalid, check whether the access request is an input request or an output request (step 10).
4) If it is an input request, do nothing and perform the termination process. If it is an output request, the real memory allocation is performed by mechanism 4.
0 allocates real memory to the block (step 10
6) Requests the table storage mechanism 5 to perform storage processing (step 107), and outputs an access request to the secondary storage device 3 (step 108).

The real memory allocation process of the real memory allocation mechanism 40 finds a free block from the free real memory management table 2, registers the real address in the corresponding field 12 of the address conversion table 1, and sends it to the flag section 1.
3 is enabled and the block in Management Table 2 is in use, the real block to be allocated to 0 is determined by assigning the same real memory as the real memory allocated to the nearby logical address in order to reduce seek operations. It is also possible to easily realize a cylinder or the real memory of a cylinder in which a magnetic head is present as a priority allocation candidate by configuring a management table in advance with consideration to processing efficiency.

Note that the access mechanism 4 may be configured to prepare an instruction to allocate a real storage area to a logical address, and return an error if the corresponding entry is invalid at the time of access. The user can obtain the same effect by instructing real storage area allocation upon error return due to the cause and re-executing.

FIG. 3 shows an example of processing by the table storage mechanism 5. The table storage mechanism 5 includes an address conversion table 1 and a free real storage management table 2.
These tables perform the process of writing to the secondary storage device 3,
It manages the correspondence between real memory and stored information, and is very important information, so high reliability is required. For this reason, a storage area 31 is provided in the secondary storage device 3, an updating flag 32 is added to it, and the flag 32 is set at the beginning and end of the process.
Steps 201 and 204 for setting 2 are provided, and a step 202 for saving the pre-update information in the storage area 31 is provided before step 203 for writing the conversion table 1 and management table 2 in the table storage area 33.34.

As a result, even if the save is interrupted due to an abnormal situation during the update process, the table can be recovered using the pre-update information in the save area 31. Note that similar information recovery processing can also be realized by duplicating the table storage areas 33 and 34 and providing two display screens for updating.

If reliability is not an issue, step 202 may be omitted. In this case, a mechanism is incorporated that starts recovery processing for the entire device when it is determined that recovery is necessary based on the updating flag 32.

Note that the storage light of address conversion table 1 and free real storage management table 2 may be affected if the device where these tables exist becomes a failure or
Any storage area is sufficient as long as there is no risk of information being lost in the event of a power outage, and the actual memory allocation may be in the target device or another device, and the storage process may be performed on the changed part. It is only necessary to carry out the process for the surface metal body.

FIG. 4 is an example of a configuration in which the present invention is used in a multiplexed environment.
In particular, it shows the relationship between the serialization mechanism 6 and the access mechanism 4 that is necessary in that case.

When used in a multiprocessing environment, when updating the address translation table, the access mechanism 4 obtains permission from the serialization mechanism 6 before referencing it in order to prevent it from being updated by other accesses during this update process. (Steps 301 to 304
), notifies the serialization mechanism of completion after the operations related to the conversion table and the management table are completed (steps 305 and 306
), in this configuration example, the serialization mechanism is not used for accesses that do not require updating, but the serialization mechanism may be used in cases such as when changing the conversion information of a logical address that has already been allocated. I will do it.

The serialization mechanism 6 is not only one that is confined within a single processor, but also one that performs serial processing between a plurality of processors.

FIG. 5 is a conceptual diagram of another embodiment of the present invention, in which address conversion table 1 is changed so that a file (data set) and its logical address can be easily determined from a real address, and a file (data set) and its logical address are changed from a real address. A real address translation mechanism 7 is added to obtain a logical address.

Upon receiving a real address translation request instruction from the user, the real address translation mechanism 7 examines the address translation table 1, creates a list of files to which the relevant real storage area is allocated and their logical addresses, and sends the list to the user. return. Of course, there are two ways to specify a real address: specifying an address range and specifying an address list, and two ways to specify an address range: specifying the start and end, and specifying the start and size. Both methods are easy to implement. Note that the address conversion table 1 may be configured as shown in Figure 1, and the conversion table from real addresses to logical addresses may be integrated with the free real memory management table. This can be easily achieved by using the following techniques.

[Effects of the Invention J] As is clear from the above description, according to the present invention, when initializing a file, the user anticipates additions and expansions in the future, and does not write to the file in the space portion such as the free real storage management table. By skipping the process and writing only the blocks containing valid information, the user can use a larger file space than the storage device actually used. As a result, the burden of managing storage space is significantly reduced, and file capacity design becomes easier. It brings great side effects, such as making software design easier and eliminating the need to reorganize files due to lack of space.

In addition, in the configuration of claim (1), uncorrelated logical blocks of multiple files are stored in a certain real storage area, so if restoration is required due to a media failure, etc., the range that needs restoration is becomes very large. On the other hand, according to claim (2), it is possible to easily obtain information on files and logical blocks that need to be restored from the address range of real memory indicating the location of the failure, thereby significantly reducing the restoration range. This greatly improves its availability as a storage memory.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of an embodiment of the present invention, Fig. 2 is a processing flow diagram of the access mechanism, Fig. 3 is a processing flow diagram of the table storage mechanism, and Fig. M4 is the time when the present invention is adapted to a multiprocessing environment. FIG. 5 is a conceptual diagram of another embodiment of the present invention. I... Address conversion table, 2... Free real storage management table,
3... Secondary storage device, 33... Address translation table storage area, 34... Free real storage management table storage area, 4... Access mechanism, 5... Table storage mechanism, 7...
Real address translation mechanism. Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) The storage area of secondary storage in a computer system is divided into logical units (hereinafter referred to as files) and managed, and the storage area within these files is accessed by an independent address (logical address) for each file. In the file storage method to be accessed, it has judgment information as to whether real memory is unallocated or not corresponding to a logical address, has a conversion table from a logical address to a real address, and a management table that manages free real storage area, When a request is accepted, the conversion table is searched, and it is determined whether or not it is unallocated based on the judgment information of the entry corresponding to the logical address. If it is unallocated, free real memory is allocated using the management table before accessing. In addition, the file storage method is characterized in that the conversion table and the management table are stored in a storage area for each failure, which is different from the location where the conversion table and the management table exist. (2) The file storage system according to claim (1), further comprising a conversion mechanism for determining a file and its logical address from a real address.