JPH07182116A - External storage - Google Patents

Abstract

PURPOSE:To attain fault processing of an optical disk without applying any load to a host by sending the abnormal optical disk to an optical disk access device and transferring the data sent to a data cache device to a reserved optical disk device. CONSTITUTION:When it is decided that an optical disk is abnormal, a request is given to a sending mechanism 36 to send the abnormal disk to an optical disk access device 18. Then the data stored in the abnormal disk are sent to a data cache device 16 from the device 18. At the same time, the data under transfer are registered in an address table 30. When all data of the abnormal disk are sent to the device 16, a controller 12 gives a request to the mechanism 36 to return the abnormal disk to a storing shelf 34. Then the position of the abnormal disk is exchanged with the position of the shelf 34 of a reserved optical disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collective type optical disk having a storage shelf for storing a plurality of optical disks, an optical disk access device, and a transfer mechanism for transferring an optical disk between the storage shelf and the optical disk access device. The present invention relates to an external storage device using a device, and more particularly to an external storage device capable of automatically repairing a failed optical disk.

[0002]

2. Description of the Related Art Conventionally, an optical disk device has been widely used as an external storage device of a computer due to its characteristics such as large capacity, random accessibility and exchangeability.

[0003]

However, in the optical disk device, since the optical disk, which is a storage medium, can be removed from the apparatus, there is a high probability that a defect of writing due to a problem of the optical disk or a defect of reading due to it is high. There is a point.

As a countermeasure against such a problem, the administrator of the host computer regularly backs up the data on the optical disk to another medium, and the data backed up at the time when the problem occurs to another optical disk. The problem was repaired by transferring it.

However, in such a method, (1) it is necessary to make a backup only for the used optical disk, and the capacity is large. (2) Due to (1), it takes a lot of time to take a backup. (3) When the defect is repaired, the data recovery after the previous backup is not guaranteed. There is such a problem.

The present invention has been made to solve the above-mentioned conventional problems. It has a small capacity for media for repairing defects, reduces the load on the host side, reduces the probability of data loss, and automatically writes optical disks. It is an object of the present invention to provide an external storage device that can be restored.

[0007]

The present invention provides a storage shelf for storing a plurality of optical disks, an optical disk access device, and
An aggregate optical disc device having a transport mechanism for transporting an optical disc between the storage shelf and the optical disc access device, and a cache memory of the aggregate optical disc device in block units, which is a predetermined number of data of consecutive optical disc addresses. A data cache device used,
A failure-preventing optical disk arranged on the storage shelf as a reserve in the collective-type optical disk apparatus, a mechanism for detecting the occurrence of a failure of the optical disk, data transfer between the data cache storage apparatus of the optical disk and the optical disk, and a collective-type An external storage device comprising a controller for controlling the transport of an optical disk of an optical disk device and a data transfer between the external storage device and a host, the optical disk having a failure when the controller has the failure. The above object is achieved by automatically avoiding a failure of the optical disk by transferring the data of (1) to the cache memory and then transferring the data to the reserved optical disk.

[0008]

According to the present invention, the controller has the information indicating which data of the optical disk on the storage shelf is stored in the data cache device, and transmits the request from the host to each device. If the request is for the optical disk access device, the controller refers to the information, and if the requested data is in the data cache device, issues a request to the data cache device and the requested data is the data cache device. If not, issue a request to the optical disk access device.

Further, the controller confirms an optical disc abnormality with respect to the optical disc failure detection mechanism within a range not hindering the host request. If there is an abnormality, the optical disc transport mechanism transports the abnormal optical disc to the optical disc access device and transfers the data to the data cache device. At this time, the controller keeps track of which data has been transferred. afterwards,
The optical disk carrying mechanism returns the abnormal optical disk to the storage shelf, and the reserved optical disk is carried to the optical disk access device. Finally, by transferring the data transferred to the data cache device to the reserved optical disk, the failure of the optical disk can be automatically repaired.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an outline of a first embodiment according to the present invention.

In FIG. 1, an external storage device 10 is connected to the host 20, and comprises a controller 12, a collective type optical disk device 14 and a data cache device 16. The collective optical disk device 14 includes an optical disk access device 18 and a storage shelf 3 for storing a plurality of optical disks.
4, a transport mechanism 36 for transporting an optical disk between the storage shelf 34 and the optical disk access device 18, and a failure detection mechanism 32 for detecting a failure of the optical disk. or,
The controller 12 is provided with an address correspondence table 30 showing information indicating which data of the optical discs in the storage shelves 34 is cached in the data cache device 16, and data transfer between the data cache device 16 and the optical discs, a collective type optical disc. The optical disc transport control of the device 14 and the data transfer control between the external storage device 10 and the host 20 are performed.

The controller 12 responds to the request issued from the host 20 by the collective type optical disk device 14
To the optical disc device 14
Issue a request corresponding to. If the request from the host 20 is a request to the optical disk access device 18, the controller 12 refers to the address correspondence table 30, and if it is determined that the requested data is cached in the data cache device 16. , If a request is issued to the data cache device 16 and the requested data is not cached in the data cache device 16,
A request is issued to the optical disk access device 18.

Further, the controller 12 is the host 2 described above.
A request for confirming whether or not there is an abnormality in the optical disk is issued to the failure detection mechanism 32 of the optical disk within a range not hindering the request from 0. In response to this request, when it is determined that a certain optical disc is abnormal, a request is issued to the transport mechanism 36 to transport the abnormal optical disc to the optical disc access device 18. Next, the optical disk access device 18 transfers the abnormal optical disk data to the data cache device 16. At this time, which data is transferred is registered in the address correspondence table 30. When the transfer of all the data on the defective optical disk to the data cache device 16 is completed, the controller 12 issues a request for the transport mechanism 36 to return the defective optical disk to the storage shelf 34.

After that, the controller 12 issues a request to the transport mechanism 36 to transport the reserved optical disc to the optical disc access device 18. After the transportation is completed, the controller 12 transfers the cached data to the reserved optical disk. After the transfer is completed, the positions of the storage shelves 34 of the failed optical disk and the reserved optical disk are exchanged.

After this process, the host 20 makes an access request to the optical disk in which the failure has occurred, so that the host 20 does not deal with the failure regardless of the occurrence of the failure. It becomes accessible.

FIG. 2 is a block diagram showing the outline of the second embodiment according to the present invention.

The device configuration of the second embodiment is almost the same as that of the first embodiment, except that the collective type optical disk device 14 of the first embodiment has two optical disk access devices instead of the failure detection mechanism 32. 18 and 19 are provided. The optical disk access devices 18 and 19 are equipped with a mechanism for detecting a failure of the optical disk.

The failure detection mechanism in the second embodiment is the EDAC (Error) normally provided in the optical disk access device.
This is performed as follows using the Detect And Correct function.

First, the ability of a normal EDAC, for example, the number of bytes for correcting an error is set to half of the normal value, and when an event that cannot correct the error occurs in this state, it is determined that the optical disk is a failure. Is. When such an event occurs, the error correction capability is returned to the maximum and the request from the host is processed.

Similar to the first embodiment, the controller 12
In response to the request issued from the host 20, if the request is for the collective optical disk device 14, then the corresponding request is issued to the collective optical disk device 14. If the request from the host 20 is a request to the optical disk access device 18, the controller 12 refers to the address correspondence table 30, and if it is determined that the requested data is cached in the data cache device 16. , Issues a request to the data cache device 16,
If the requested data is not cached in the data cache device 16, the optical disc access device 18
Issue a request to.

Further, the controller 12 is the host 20.
If there is no request from the optical disc access device 19 for 10 seconds, a request is issued to the transport mechanism 36 to transport the optical discs in the storage shelf 34 to the optical disc access device 19 in order, and a read request for the optical disc is issued. The presence or absence of is detected. If no failure is detected, the transport mechanism 36 is requested to transport the optical disc from the optical disc access device 19 to the storage shelf 34. After that, the optical disc is conveyed to the optical disc access device 19, and the presence or absence of a fault in the optical disc is detected. These processes are performed on all the optical disks to detect the presence / absence of a failure.

When it is determined that a certain optical disc is abnormal, the data of the abnormal optical disc is sent from the optical disc access device 18 to the data cache device 1 at that time.
Transfer to 6. At this time, which data is transferred is registered in the address correspondence table 30. When the transfer of all the data on the defective optical disc to the data cache device 16 is completed, the controller 12 issues a request to the transport mechanism 36 to transport the reserved optical disc to the optical disc access device 18. After the transportation is completed,
The controller 12 transfers the cached data to the reserved optical disk. After the transfer is completed, the optical disc access device 19 issues a request to the transport mechanism 36 to return the faulty optical disc to the storage shelf 34 in which the reserved optical disc was mounted.

After that, a request is issued to the transport mechanism 36 to return the reserved optical disk to the storage shelf 34 on which the defective optical disk was mounted. After that, the display lamp indicates that a failure has occurred. In such a case, a new failure can be dealt with by ejecting the failed optical disk during maintenance of the external storage device 10 and inserting a new optical disk as a reserve into the collective optical disk device 14.

If there is a request from the host 20 during the processing of the above-mentioned optical disk failure, the transfer from the optical disk or the transfer to the optical disk is interrupted,
Execute the request from the host. Since the interrupted processing is continued after the processing of the request is completed, the request from the host is not affected. The continuation of the processing can be easily executed by referring to the address correspondence table 30. As a result, the failure processing of the optical disk can be automatically performed without causing the host 20 to perform the failure processing work.

[0026]

As described above, according to the present invention, there is an effect that the failure processing of the optical disk can be executed with almost no load on the host. Further, conventionally, a backup having the same capacity as that of the optical disk was required for a failure, but the present invention has an effect that it can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a gist of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a gist of a second embodiment of the present invention.

[Explanation of symbols]

 10 ... External storage device 12 ... Controller 14 ... Collective type optical disk device 16 ... Data cache device 18, 19 ... Optical disk access device 20 ... Host 30 ... Address correspondence table 32 ... Failure detection mechanism 34 ... Storage shelf 36 ... Optical disk transport mechanism

Claims (1)

[Claims] 1. A storage shelf for storing a plurality of optical disks, an optical disk access device, and a collective type optical disk device having a transport mechanism for transporting optical disks between the storage shelf and the optical disk access device; A data cache device used as a cache memory of the collective optical disk device in units of blocks, which is a predetermined number of data, an optical disk for failure protection arranged on the storage shelf as a reserve in the collective optical disk device, and an optical disk failure A controller for controlling the data transfer between the data cache storage device of the optical disc and the optical disc, the transport control of the optical disc of the collective optical disc device, and the data transfer between the external storage device and the host. An external storage device comprising: The controller automatically avoids the failure of the optical disk by transferring the data of the failed optical disk to the cache memory when the failure occurs and then transferring the data to the reserved optical disk. Characteristic external storage device.