JPH0830398A - Optical disc system - Google Patents

Abstract

(57) [Abstract] [Purpose] An optical disc system in which data is written to a medium via a cache memory, in which data loss is prevented when a failure occurs and reliability of data writing is improved. When a failure occurs in an optical disk device, data waiting to be written to the optical disk device, which is temporarily stored in a cache memory, is saved in a save area prepared in advance in the magnetic disk device. After that, when the failure of the optical disk device is recovered, the saved write-waiting data is written to the optical disk to be originally written. By providing the above-described data guarantee function, it is possible to prevent data loss when a failure occurs in the optical disk device and improve the reliability of data writing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk system, and more particularly to an optical disk system for writing data on an optical disk via a cache memory.

[0002]

2. Description of the Related Art In recent years, with the spread of CSS (client / server system), a personal computer (P
There are an increasing number of cases where network systems are constructed using C) and workstations (WS) as servers. In such a network system, a magnetic disk device or an optical disk device is often connected to a PC or WS used as a server machine to perform centralized management of data commonly used in the network system. In this case, in a server machine to which an optical disk device whose access speed is generally slower than that of a magnetic disk device is connected, data is written on the optical disk via a cache memory as described in Japanese Patent Laid-Open No. 5-73413. By doing so, the access speed is improved.

[0003]

In the above conventional technique, when a program writes a data write request to an optical disc, when the data write to the cache memory provided for the optical disc is completed,
The OS notifies the program that the data writing is completed. As a result, the program can execute the next process at the time when the data writing to the cache memory is completed, so that the apparent access speed to the optical disk is improved. However, if a failure occurs in the optical disk device between the notification that the data writing is completed and the writing of the data temporarily stored in the cache memory to the optical disk is completed, all the data in the cache memory becomes invalid. However, there is a problem in that data that the program should have written to the optical disk is lost, resulting in data loss. In particular, optical disc devices often fail due to dust,
There is a problem that the above-mentioned risk of data loss is great.

Therefore, an object of the present invention is to solve the above-mentioned problems, prevent data loss when an optical disk device in which data is written via a cache memory has a failure, and improve reliability of data writing. It is to provide an optical disk system that can be improved.

[0005]

In order to achieve the above-mentioned object, the optical disk system of the present invention is configured as either (1) or (2) shown below.

(1) In an optical disc system in which data is written to an optical disc loaded in the optical disc device via a cache memory, when a failure occurs in the optical disc device, the write wait data temporarily stored in the cache memory is written. In addition to being saved in another nonvolatile storage medium, a data guarantee function is provided to write the saved write-waiting data to the optical disk when the failure is recovered in the optical disk device.

(2) In an optical disc system including a plurality of optical disc devices, in which data is written to an optical disc loaded in the optical disc device via a cache memory, the cache memory is used when a failure occurs in the optical disc device. In this configuration, the write waiting data temporarily stored in the optical disk is written on the optical disk by using another normal optical disk device.

[0008]

[Operation] The operation based on the configuration of (1) or (2) will be described.

(1) In the optical disc system (part 1) of the present invention, in the optical disc system in which the data writing process to the optical disc loaded in the optical disc device is performed through the cache memory, when a failure occurs in the optical disc device, A configuration having a data assurance function of saving the write-waiting data temporarily stored in the cache memory to another nonvolatile storage medium and writing the saved write-waiting data to the optical disc at the time of failure recovery in the optical disc device. By doing so, it is possible to prevent the loss of write-waiting data and improve the reliability of data writing.

(2) In the optical disc system (2) of the present invention, the optical disc system is provided with a plurality of optical disc devices, and the data writing process to the optical disc loaded in the optical disc device is performed through the cache memory. When a failure occurs in an optical disk device, the data waiting function temporarily stored in the cache memory is written to the optical disk by using another normal optical disk device. It is possible to prevent this, improve the reliability of data writing, and improve the operational performance of the entire system.

[0011]

Embodiments of the optical disk system of the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a block diagram showing an example of the configuration of a file server including the optical disc system of the present invention.
In the figure, 101 is a central processing unit (CPU), 10
2 is a main memory (MM), 103 is an I / F unit (I / F)
F), 104 is a mouse (MS), 105 is a keyboard (KBD), 106 is a display control unit (CRTA), 107
Is a display device (CRT), 108 is a LAN connection unit (LANA) for connecting to another client device via a LAN (local area network), 109 is a device control unit for magnetic disk (SCSIA), and 110 is a magnetic disk. Disk drive (HDK) controlled by the device control unit SCSIA 109, 111 is an optical disk device control unit (SCSIA), and 112 is a cache memory (CA) for improving the apparent access speed.
CH), 113 is an optical disk device control unit SCSIA
Optical disc library device (OL
U), 114 are system buses (BUS), and 115 and 116 are SCSI buses.

In FIG. 1, the entire file server is a CP.
It is controlled by U101, and the mouse 104 and the keyboard 105 are connected to the internal system bus 114.
I / F unit 103 for controlling the display, display control unit 106 for controlling the CRT 107, LANA 108, and SCSI for controlling the magnetic disk device (HDK) 110 which is the primary storage medium
A109, a SCSIA111 for controlling an optical disk library unit (OLU) 113 which is a secondary storage medium
Are connected to each other. Also, SCSI11
1 has a cache memory (CACH) 112 for increasing the access speed to the OLU 113.
Has been implemented.

FIG. 2 is a diagram showing a hardware configuration example of an optical disc device portion in the optical disc system shown in FIG. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. 201 is an OLU
A control unit (CNTL), 202 is a SCSI control unit (SCS).
IC), 203 is an optical disk loading control unit (ACC), 2
Reference numeral 04 is an optical disk drive control unit (OFC), 205 to 20
Reference numeral 8 is an optical disk drive (ODD), and 209 is an optical disk. In FIG. 2, SCSIA 111 and OLU
113 and SCSI (Small Computer System Int)
erface) system, and the SCSI control unit 202
Data is input to and output from the OLU 113 via the SCSI bus 116. An optical disk loading controller (ACC) 203 and an optical disk drive controller (OFC) 204 in the OLU 113 are connected to the SCSI bus 116. In this embodiment, the data sent from the system bus 114 to the SCSIA 111 is temporarily stored in the cache memory 112 as write wait data. The OLU control unit 201 notifies the CPU 101 in FIG.
The process of writing data to is started. In the data write process, first, C is transferred via the SCSI bus 116.
The NTL 201 instructs the ACC 203 to load an optical disc on which data is to be written into one of the designated ODDs. And when loading is completed, O
FC204 is the CACH1 for the optical disc being loaded.
The writing of the write wait data received from 12 is started. At this time, the data in the CACH 112 is not erased until the writing of all the write-waiting data is completed.

FIG. 3 is a diagram showing a correspondence relationship between each storage medium and a memory address in the optical disc system of FIG. In the OLU, the ejection and loading operation of the optical disc is frequently performed (for example, when the designated ODD is already loaded with the optical disc, the optical disc is ejected once and the required optical disc is loaded).
Therefore, the access time becomes longer than that of a magnetic disk device or the like. Therefore, on the memory address, the main memory (MM) 301, the magnetic disk device (HDK)
A method is generally used in which the data area 302 corresponding to 110 and the data area 303 corresponding to the OLU 113 are hierarchically managed and the data having a higher access frequency are sequentially stored in a storage medium having a higher access speed. FIG. 3 shows an example in which each storage medium is assigned to memory addresses in the order of high access frequency.

FIG. 4 is an explanatory diagram concerning the data guarantee function when a failure occurs in the optical disk device portion. In the figure, the same components as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 4, CPU1
The transfer of the write data from 01 to the OFC 204 is performed in the order of I → II → IV → V in the figure when the optical disk device portion is operating normally. At this time, CPU1
When the data writing from 01 to the CACH 112 in the SCSIA 111 is completed, S is written by III in the figure.
The CSIA 111 sends a data transfer end report to the CPU 101. On the other hand, for some reason (for example,
OD due to the intrusion of dust when the optical disc is removed or loaded
If a write error in D occurs, SCSIA
The 111 reports an error to the CPU 101 by iii in the figure. Then, the CPU 1 that received the error report
01 saves the data in the cache memory 112 to the save area previously allocated to the magnetic disk device 110. As a result, the cache memory 11
It is possible to prevent the data in 2 from being invalidated due to the occurrence of a failure in the optical disk device and causing the data loss.

FIG. 5 is a diagram showing a state of saving write-waiting data by the data guarantee function. FIG. 5A shows correspondence between each storage medium and memory address in the optical disk system having write-waiting data in the save state. As for the relationship, FIG. 5B shows an address map for managing the storage destination of the saved write-waiting data. In the figure, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

For example, in FIG. 5A, the write wait data temporarily stored in the cache memory assigned to the address area 502 (logical addresses A # to B #) is set to O
When writing cannot be performed due to a problem in LU 113, address area 501 (logical address A # 'to B #')
Area of the HDK110 allocated to the
The write wait data is stored in 2), and the CPU 10
1 is the start address 601 (A #, A # ') of the logical address that identifies the save source address area 502 and the save destination address area 501 according to the address map of FIG. 5B.
It also manages the final address 602 (B #, B # '). After that, when the malfunction of the OLU 113 is corrected and normal operation is confirmed, the CPU 101 deletes the write-waiting data saved in the save area 402 (address area 501) of the HDK 110 based on the address map of FIG. 5B. The operation of reading and writing to the OLU 113 again is performed, and when the operation is normally completed, the address map of FIG. 5B is invalidated.

FIG. 6 is an explanatory diagram of a data guarantee function when a failure occurs in an optical disk device portion in an optical disk system including a plurality of optical disk devices. FIG. 6A shows that all the optical disk devices are normal. FIG. 6B shows a correspondence relationship between each storage medium and a memory address in the operating optical disk system, and FIG. 6B shows a correspondence relationship between each storage medium and a memory address in the optical disk system when a failure occurs in a certain optical disk device. , Respectively. In the figure, the same components as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

As described above, in the OLU, when the exchange of the optical disk as the medium occurs internally, the processing speed is significantly reduced. Therefore, as shown in FIG.
In the OLU having (ODD1 to ODD4), the specific optical disc 703 having the highest access frequency among the optical discs managed by the OLU is assigned to the specific ODD (FIG.
In (a), the ODD1) is always fixedly loaded, and an address area 701 dedicated to the ODD1 is fixed.
May be allocated separately from the shared address area 702 for the other ODD2 to ODD4 to speed up the service provision. However, if a failure occurs in the ODD 1 due to dust or the like, the specific optical disc 703 is reloaded into another normal ODD 2 and the OD is restored.
A dedicated address area 704 is assigned to D2, and O
By allocating the shared address area 705 to the ODD3 and ODD4 other than the DD1, the processing operation of the entire system is continued.

As described above, according to the present embodiment, it is possible to prevent the loss of the write-waiting data temporarily stored in the cache memory, improve the reliability of data writing, and improve the operation performance of the entire system. it can.

Incidentally, the "optical disk" which is the object of the present embodiment includes what is generally called a magneto-optical disk. Further, as long as data can be written, an optical disc (magneto-optical disc) that can be written only once or an optical disc (magneto-optical disc) that can be written many times may be used.

[0023]

【The invention's effect】

(1) As described in detail above, according to the optical disc system (No. 1) of the present invention, in the optical disc system in which the data writing process to the optical disc loaded in the optical disc device is performed through the cache memory, the optical disc device When a failure occurs, the write-waiting data temporarily stored in the cache memory is saved to another non-volatile storage medium, and at the time of failure recovery in the optical disk device, the saved write-waiting data is written to the optical disk. With the configuration having the function, it is possible to obtain an effect that it is possible to prevent the loss of write-waiting data and improve the reliability of data writing.

(2) Alternatively, according to the optical disk system (No. 2) of the present invention, a plurality of optical disk devices are provided, and the data writing process to the optical disk loaded in the optical disk device is performed via the cache memory. In the optical disk system, when a failure occurs in a certain optical disk device, the data waiting function temporarily written in the cache memory is written to the optical disk by using another normal optical disk device. It is possible to prevent the loss of data, improve the reliability of data writing, and improve the operation performance of the entire system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a file server including an optical disc system of the present invention.

FIG. 2 is a diagram showing a hardware configuration example of an optical disc device portion in the optical disc system in FIG.

3 is a diagram showing a correspondence relationship between each storage medium and a memory address in the optical disc system of FIG.

FIG. 4 is an explanatory diagram regarding a data guarantee function when a failure occurs in an optical disk device portion.

FIG. 5 is a diagram showing a state of saving write-waiting data by a data guarantee function.

FIG. 6 is an explanatory diagram relating to a data guarantee function when a failure occurs in an optical disk device portion in an optical disk system including a plurality of optical disk devices.

[Explanation of symbols]

 112 cache memory 113 optical disk library device 201 optical disk device interface control unit

Claims (2)

[Claims] 1. An optical disc system in which data is written to an optical disc loaded in an optical disc device through a cache memory, and when a failure occurs in the optical disc device, the write-waiting data temporarily stored in the cache memory 2. An optical disc system having a data guarantee function of writing the saved write-waiting data to the optical disc at the time of failure recovery in the optical disc device while saving the data to the non-volatile storage medium. 2. An optical disc system comprising a plurality of optical disc devices, wherein data writing processing to an optical disc loaded in the optical disc device is performed via a cache memory, wherein when a failure occurs in a certain optical disc device, the cache memory is stored in the cache memory. An optical disc system having a data guarantee function for writing temporarily stored write-waiting data to an optical disc using another normal optical disc device.