Dynamic magnetic information storage or retrieval – General recording or reproducing – Recording-or erasing-prevention
Reexamination Certificate
1995-12-15
2001-11-13
Neal, Regina Y. (Department: 2651)
Dynamic magnetic information storage or retrieval
General recording or reproducing
Recording-or erasing-prevention
Reexamination Certificate
active
06317281
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a disk storage device having a rotary recording/reproducing medium, and in particular to a disk storage device capable of improving reliability of recorded data by preventing intentional or accidental destruction of recorded data.
A conventional disk storage is connected to a host device via an interface such as SCSI (Small Computer System Interface). As for the control command of the disk storage device used in this interface, the disk storage device which has received the command cannot determine whether the control command is correct. Therefore, the disk storage device unconditionally executes operation, such as a read or write operation, ordered by the control command.
At the present time, the position occupied by auxiliary storage devices such as disk storage devices in computer systems becomes increasingly important. That is to say, an application program for conducting increasingly complicated and sophisticated processing, and precious user data such as deposit balance are preserved in the disk storage device. At the same time, however, there is an enhanced risk that nonreplaceable precious data preserved in the disk storage device will be destroyed because of a processing error of the application program in the host device, an operation mistake of an operator handling the system, or the existence of a computer virus which is now constituting a social problem.
In order to prevent such a risk of user data destruction, a file management method has been proposed in JP-A-4-287254, for example. According to the file management method, an OS (Operation System) for controlling the host device manages the storage area of the disk storage device in order to prevent abnormal data being written into the disk storage device.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a disk storage device capable of giving hardware protection to user data therein.
In accordance with an aspect of an embodiment of the present invention, a disk storage device includes a data transfer control device for transferring data from a higher rank device to a storage medium and transferring data from the storage medium to the higher rank device, an identification device having identification information for determining whether it should be permitted or inhibited to write data into a predetermined recording area of the storage medium, and data transfer command device, responsive to a data recording command given by the higher rank device, to order the data transfer control device to write data into the storage medium according to the identification information of the identification device.
The data transfer command device is a microprocessor. In response to a data write command given to the storage medium by the higher rank device, this microprocessor does not order the data transfer control device to transfer data to the storage medium when the identification information possessed by a predetermined sector of the storage medium indicates data write inhibition.
When the identification information possessed by a predetermined sector of the storage medium indicates data write inhibition in response to the data write command, the microprocessor informs the higher rank device of this write inhibition error.
Furthermore, a state display device is connected to the microprocessor. When the identification information possessed by a predetermined sector of the storage medium indicates data write inhibition in response to the data write command, the state display device displays a data write inhibition error of the predetermined sector in response to an order given by the microprocessor.
When the state display device displays a data write inhibition error of the predetermined sector, the microprocessor allows selection of running stop, running continuation, or low-speed data transfer running by specifying beforehand the operation to be conducted at the time of error occurrence in accordance with a command given to the disk storage device by the host computer or by changing over a switch mounted on the disk storage device to manual operation beforehand.
When the higher rank device sends a command for initializing the storage medium to the disk storage device at the time of normal operation, the microprocessor inhibits acceptance of the command and orders display of this inhibition state on the state display device.
The identification information possessed by the identification device is flag information possessed by each sector on each track of the storage medium. This flag information includes a combination of three bits indicating whether a data portion corresponding to the flag information is a bad sector, an alternate sector, or a reserve sector.
Furthermore, the flag information includes an “overwrite” flag for permitting data overwriting on the data portion, a “one time write” flag for permitting write operation only once, and a “write protect” flag for inhibiting data writing.
When a data write command is given to the storage medium by the higher rank device, the microprocessor checks the “overwrite” flag, the “one time write” flag, and the “write protect” flag of the flag information. If the “write protect” flag is on in response to the data write command, the microprocessor does not order the data transfer control device to execute the operation for writing data into the data portion of the sector. In case of “one time write” flag, the microprocessor changes the flag to the “write protect” flag after data have been written into the medium.
The identification information including the flag information is stored in a memory. In response to the data write command given to the storage medium by the higher rank device, reference to the identification information is made and the microprocessor determines whether or not the microprocessor should order the data transfer control device to execute writing.
The memory includes a nonvolatile memory. When a data write command given by the higher rank device is write inhibit, the nonvolatile memory is rewritten so that the “write protect” flag of the flag information may turn on.
The memory includes a volatile memory. When a data write command given by the higher rank device is write inhibit, the flag information is temporarily preserved in the volatile memory so that the “write protect” flag of the flag information may turn on. When a magnetic head is squared with a predetermined sector according to rotation of the sector, the flag information of the volatile memory is written into the sector.
Owing to the above described configuration of the invention, data from the host computer is prevented from being written into the disk storage device as a result of an operation mistake of a user operating the higher rank device such as a host computer or as a result of an operation aimed at destroying user data.
REFERENCES:
patent: Re. 33328 (1990-09-01), Director
patent: 4549295 (1985-10-01), Purvis
patent: 4760566 (1988-07-01), Kobayashi et al.
patent: 4774700 (1988-09-01), Satoh et al.
patent: 5060218 (1991-10-01), Chiyomatsu
patent: 5136569 (1992-08-01), Fennema et al.
patent: 5265230 (1993-11-01), Saldanha et al.
patent: 5283779 (1994-02-01), Otsuki
patent: 5341359 (1994-08-01), Birukawa et al.
patent: 5369533 (1994-11-01), Ottensen et al.
patent: 5379380 (1995-01-01), Mori et al.
patent: 5485439 (1996-01-01), Hamasaka et al.
patent: 5525902 (1996-06-01), Nakajima et al.
patent: 5657473 (1997-08-01), Killean et al.
patent: 59-175064 (1984-10-01), None
patent: 4-287254 (1992-10-01), None
patent: 2-183461 (1994-07-01), None
Katayama Yukari
Kojima Akira
Ogawa Hitoshi
Saiki Eisaku
Tsunoda Motoyasu
Crowell & Moring LLP
Hitachi , Ltd.
Neal Regina Y.
LandOfFree
Disk storage device having identification information for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disk storage device having identification information for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk storage device having identification information for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2614165