JPS60254220A - Optical disk control system with paging - Google Patents

Abstract

PURPOSE:To use an optical disk equivalently to a file on a magnetic disk by using the magnetic disk as an auxiliary device and using the optical disk equivalently to the magnetic disk with paging. CONSTITUTION:A subsystem controller 1 of an optical disk consists of a processor unit, ROM/RAM, etc. and contains a magnetic disk device 2 and an optical disk device 3. Such a controller 1 is connected to a host computer. A controller 7 sets a file having a file directory coincident with a file discriminator 211 given from a volume control area 31 of the disk 2 onto this disk 2. For this purpose, a file control page 21 is read out of an optical disk volume and written to the disk 2 at the final coincidence of the discriminator 211. While an access is carried out from the host computer by a logical address with a file space regarded as a continuous space. Thus a page converting process is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical disk control system using paging.

[Technical background of the invention and its problems]

Optical disks are large capacity randomly accessible storage media. Since data is physically written on an optical disk using a laser, the written data cannot be changed. Also, the access speed is slow compared to magnetic disks. Therefore, it cannot be used as a substitute for magnetic disks in general, and has been considered only as a save medium for image files and magnetic disk files whose contents do not change and data is added serially.

However, when using the above-mentioned magnetic disk as a save medium, the entire file is saved on an optical disk volume, so the time required for file saving and restoration cannot be ignored, and when saving, the file space is always It had the disadvantage that original disk space was consumed.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and is a computer-connected optical disk subsystem that uses a magnetic disk as an auxiliary device and uses paging to virtualize the optical disk into a large-capacity random access storage device equivalent to the magnetic disk. The purpose of this invention is to provide an optical disk control method using paging.

[Summary of the invention]

In order to achieve the above object, the present invention manages an integral multiple of one optical disk as a (-page), and the page is composed of a file management page, a K-shimatub page, and a data page. Each entry is divided into a stage/destage flag indicating whether or not staging is performed on a magnetic disk, an update flag indicating whether the page has been updated after staging, and the number of pages that the (-jimap entry) should manage. The logical address of the file is converted to an easy address by referring to the above page map page. together with the applicable en) I
Know the hierarchy of the svage mud from the level number stored in the J-I, stage the corresponding page from the optical disk to the magnetic disk according to the stage/destage flag of the K-zi map entry, and stage the corresponding page to the magnetic disk according to the update flag. The configuration is such that the tape is transferred from the disk to the optical disk.

This allows the optical disk to be used equivalently to a file on a magnetic disk, and it is possible to virtually support files that exceed the capacity of the magnetic disk. Furthermore, since staging/destaging is performed only on a page-by-page basis as necessary, high-speed processing can be achieved.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing an example of the configuration of an optical disk subsystem in which the present invention is implemented. In the figure, 1 is an optical disk subsystem control device, which is not shown in the figure.
It consists of ready-made unit configurations such as a processor unit and ROMAM memory. The ROM stores processing routines for commands issued from the host, and the microprocessor sequentially reads and executes the processing routines stored in the ROM while referring to various tables stored in the RAM. - the desired action is taken; 2 is a magnetic disk device used as an auxiliary device, a 3Fi optical disk device.

Note that the original disk subsystem 1 is connected to a host converter (not shown).

FIG. 2 is a conceptual diagram showing the structure of a file used in the present invention. In the present invention, files are managed in units of pages, which are integral multiples of one block a2 of the file Fi source disk 3. In the figure, 21 is a file management page, 22 is a page for page mapping (hereinafter simply referred to as a page map page), and 23 is a data page. In the file management section 221, 211 is a file directory consisting of a file identifier, file space information, etc., 212 is ream management information of the optical disk delete, and 213 is one or more page map pin entries constituting the page map page 22. be. 5. The data format of each entry 213 constituting the I-Jimazzo page is shown at the right end of the figure.

6- Each entry has a stage/destage flag (S/
D), update flag (UP), level number (IJV
)1,2 y7 PL/S(ADH) Consists of ka.

The stage/destaging flag contains flag information indicating whether the page has been staged to the magnetic disk 2, and the update flag contains a flag indicating whether the page has been updated after staging to the magnetic disk 2. Information is stored respectively. The level number is a number indicating the hierarchical level of the IJ, and the number of pages managed by the IJ is set and stored, that is, the number of page map entries per page.
s If the level number is n, then mn pages will be managed. Files are managed in one frame, including a file management page 2 and a page map page 22, and the memory map thereof is as shown in FIG.

The page address indicates the actual address storage position used for address conversion, and in the staging state it indicates the address on the magnetic disk 2, and in the destaging state it indicates the address on the optical disk 3. Indicates an address.

FIG. 3 is a conceptual diagram showing the configuration of an optical disk volume. In the figure, 31 indicates a volume management area, and 32 indicates a data management area. The former stores a file management page 21 that exists for each file, and the latter stores a page map page 22 and a data page 23. In the figure, the data area 32 uses optical disk blocks serially from the top address position downwards (as indicated by the arrow), and the volume management area 31 uses optical disk blocks serially from the bottom address position (as indicated by the arrow).
Arrow ■) Use Hikari Pro for the serial.

FIG. 4 is an operational conceptual diagram showing the dual configuration on a magnetic disk and an optical disk on a memory map. 1st in the diagram
Blocks labeled with the same numbers as those in FIGS. 1 to 3 are the same as those in FIGS. 1 to 3, so a description of f will be omitted here to avoid duplication.

5 to 8 are flowcharts showing the operation of the present invention, and show the respective flows of file address conversion processing, page staging, page destaging processing, and file destaging processing.

The operation of the embodiment of the present invention will be described in detail below. first,
A request to stage a file is issued from a host computer (not shown). At this time, the optical disk subsystem control device 3 stages, on the magnetic disk 2, a file having a file directory that matches the file identifier given from the /IJ name management area 31 of the magnetic disk device 2. File staging is performed by reading the last file management file 21 written to the optical disk 3 with the matching file identifier 211 from the optical disk volume and writing it to the magnetic disk 2.

At this time, only the file management page is staged. Access to a file from the host computer is performed using a logical address that regards the file space as a continuous space, and the conversion process from this logical address to (-) is shown in Figure 5. Become.

In the flowchart of FIG. 5, in step 51, a counter register value Plt built in the control device 1 is set to "'0". Step f52 calculates a control interval number based on the logical address and registers CI
Store in.

In Step 4, the I interface of the page Mazzo entry is positioned at the first page Ma, de entry of the page. In step 54, the number of pages managed by the page map entry pointed to by the pointer ■ is calculated, added to the contents of the register P1, and stored in the register P1. In step 55, the contents of register P and register CI are compared, and it is determined whether the page (value stored in the CI register) corresponding to the logical address is under the control of this (-sima, zone entry). In step 56, the contents of the stage/destage flag of the page master and entry 213 are checked to determine whether or not this page is in the stage state.In step 51, when the page is in the stage state, based on the disk address of the page, Read the page. Step 58
Now, when a page is in the destaged state, the page is staged. In step 59, the level number of the entry is checked and if "MO", the conversion process is completed. In step 60, if the contents set in register CI are not under the control of the current page map entry, the contents of register P2 are loaded into P1, The moromi interface is moved to the next page map entry and the same operation as above is repeated.In the figure, M indicates the number of Pezo Mazzo entries per page.

The page staging process follows the flowchart shown in FIG. In step 61, a page space is allocated to an empty area of the magnetic disk 2. Then, in step 62, the address information field of the page map entry is checked and if it is 0'', it is set to the initial state.In addition, in step 63, the corresponding page is read from the optical disc volume according to the address value set in the address information field, and the Stellar 7°
Write to the magnetic disk area 2 allocated in step 61. In Step 4, the value of the address information field is changed to the address of the assigned magnetic disk 2, and the stage/destage flag is set to the stage state. Writing to a file is performed to a page on the magnetic disk 2.

When a page is updated, the update flag of the page madde entry is set to 1".Updating the data page is
This means that a new page space is allocated on the optical disk 3 when a file is destaged. Therefore, the page map that points to the page map page that includes the updated page map and print entry, which will update the page storage address on the optical disk 3 that corresponds to the value set in the address information field of the page map and zoentry. The update flag of the entry is also set to 1# in advance.

Since page updates are performed on the magnetic disk 2, rewriting to the same page is possible.

File destaging processing occurs when there is a file destaging request from the host computer and when there is a request from the optical disk device 3 to mount the optical disk.

Further, the destage processing of (-) occurs when there is no page free area on the magnetic disk 3.

The page destage process is as shown in the flowchart shown in FIG. In step 71, the update flag of the page mad entry is checked to determine whether or not the page needs to be destaged. In step 72, a page is allocated to the next empty area of the optical disk 3 after the data area of the volume 32. In step 13, the contents of the corresponding page are read from the page address on the magnetic disk 2 of the page madden entry, and the contents of the page are written in the area allocated in step 2. In step 73, the value of the address information section of the page map entry is set to the address of the optical disc 3 assigned in step 12.

The file destage process is as shown in the flowchart shown in FIG. Step 81 sets (-sima, pointer ■ to the first page of the file management page, f entry. In step 82,
Point with the pointer ■ 4-Jimat! Check the contents of the entry's update flag to determine whether the page has been destaged.

In step 83, the level number of page map 6 entry is checked. In step 84, this level number is
"If not, stack that page map entry in the built-in pushdown stack memory. Step, f8
In step 5, the page map page is read from the address information field of the page manager and the directory (and the pointer I is positioned at the first page manager and zoentry of that page).

In step 86, destage processing of (-ji) is performed.

Step 81 moves the pointer I to the next page mark. Also, in the sticker 8, it is determined whether the pointer I has reached the end of the file management page.Then, in the sticker 89, it is determined whether the tack memory is empty or not. Stella 7°90
Now, pop the above item from the down stack and set its contents to the pointer ■.

Then, update the delume management information on Ste.zo91 and check the original disc? Write to the next free area of the volume 31.

〔Effect of the invention〕

As explained above, according to the present invention, an optical disk can be used equivalently to a file on a magnetic disk, and a file space larger than the capacity of the magnetic disk can be virtually created.
e-). In addition to the above, the following effects are achieved.

(1) Files can be updated logically, and updates are performed on the magnetic disk until the page is destaged, so the space efficiency of the optical disk is good.

(2) Access to staged pages is performed using a magnetic disk, so access to the same page can be made faster.

(3) Staging is performed page by page only for necessary pages, so it is faster and faster than file storage.
Moreover, no special pretreatment is required.

(4) Destaging writes only updated pages back to the optical disk, so the optical disk is more efficient and faster than saving the entire file.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing an example of the configuration of an optical disk subsystem in which the present invention is implemented, Figure 2 is a conceptual diagram showing the configuration of files used in the present invention, and Figure 3 is an optical disk volume. 4 is a conceptual diagram showing the page structure on a magnetic disk and an optical disk on a memory map, and FIGS. 5 to 8 are flowcharts showing the operation of the present invention. , file address conversion processing,
Page stage processing, (-ji destaging processing, file destaging processing are shown. 1-0-Optical disk subsystem control device, 2... Magnetic disk device, 3... Optical disk device, 21・・・
File management (-ji, 22, 213... page, page, 23... data page, 211... file directory, 212... is the volume management information. Applicant's agent, patent attorney, Takehiko Suzue 17-1

Claims (1)

[Claims] An optical disk subsystem consisting of an optical disk that uses a magnetic disk as an auxiliary device, is connected to the magnetic disk via a control device, and manages an integral multiple of one block as a page, and the control device A stage/destination flag indicating whether or not the page has been staged to disk, an update flag indicating whether the page has been updated after staging, and an address on a magnetic disk or an address on an optical disk in the staging or destaging state, respectively. It consists of address information indicating the address, and a level number indicating the number of pages that the nuclear pager and pupil should manage (-consists of at least 1 or more deentry pages (-consists of at least 1 page and the logical address of the file). is converted into a page address by referring to the above page massi page, and the hierarchy of the page map is known from the level number stored in the corresponding entry, and the corresponding page is transferred to the optical disk according to the stage/destage flag of IJ. An optical disk control method using easing, characterized in that the page is staged from the magnetic disk to the optical disk in accordance with the update flag.