摘要:
A method and apparatus for minimizing performance degradation resulting from reassignment of data to alternate sectors as a result of a defect within the original sector. For example, when a request for writing data “a” into a sector A is made but the data is written into an alternative sector A′ in an alternative sector area X because the sector A is defective. Therefore, when a write request for writing data “b” into a sector B is made subsequently, re-assignment is performed to a sector B′ subsequent to the alternative sector A′. Similarly, a defective sector C for which a request for writing data “c” is made is re-assigned an alternative sector C′. Thus, the successive data a, b, and c are written into the successive sectors A′, B′, and C′ in the same alternative sector area X, minimizing performance degradation.
摘要:
A disk storage device is disclosed for avoiding the instantaneous performance degradation as much as possible, and a method for processing a defective sector in such a disk storage device. There is executed a predetermined check related to a function of the disk storage device, preferably at least one of a read test, a write servo test, or a write test, when the disk storage device is in a waiting state where the disk storage device has no access from a host. The read test and write servo test are used to search for a defective sector on a disk and reassign the defective sector. The write test is used to indicate an abnormal condition of a head. Furthermore, the disk storage device includes a detector for detecting the waiting state, and a check logic for executing a predetermined check.
摘要:
A system and method are provided that reduce the amount of data held commonly in both high-ranking and low-ranking cache memories, thereby having each of those cache memories hold data more efficiently. More particularly, a computer system is provided with an HDC card 21 connected to an expansion bus 20 and an HDD unit 22 connected to the HDC card 21. The HDC card 21 is provided with a disk cache (high-ranking cache memory) and the HDD unit 22 is provided with a disk cache 54 (low-ranking cache memory). The HDC card 21 and the HDD unit 22 exchange select information for selecting a swap mode of each cache memory when the system is started up, thereby selecting different swap modes according to the exchanged select information respectively.
摘要:
A disk drive device comprising a disk-shaped recording medium, having a recording surface on which a plurality of tracks having a predetermined width in a radial direction are defined, said recording surface including a first area wherein a plurality of recording tracks and a plurality of non-recording tracks are located so as to form an alternating pattern along the radial direction of the recording surface. The disk drive device may further comprise: a transducer to record information on the disk-shaped recording medium; a position error detector element to detect position error relative to a target track to be recorded on; an actuator to move the transducer to the target track according to the position error; and an end-of-seek detector, wherein when the transducer is moved to a target track inside the predetermined area the end-of-seek detector determines an end of seek based on whether the position error is less than a first threshold, and when the transducer is moved to a target track outside the predetermined area, the end-of-seek detector determines an end of seek based on whether the position error is less than a second threshold, wherein the second threshold is less than the first threshold.
摘要:
A method and system are disclosed to prevent significant degradation of a data transfer rate in write cache transfer, thereby keeping the minimum data transfer rate high. The initial value Ti of the virtual buffer full capacity T(tx) is set to F/N (where F is a data capacity of the buffer, and N>1) and it is determined if the amount of write cached data S(tx) reaches the virtual buffer full capacity T(tx) so that write cache transfer is enabled during an S(tx)
摘要:
Methods and apparatus are described for a data transfer unit between a storage unit and a host, wherein a slower data transfer rate is established when a predetermined error is detected. In one embodiment the cyclicity of the error occurrence calculated and a wait is inserted between data to avoid transferring data at the calculated cyclicity point of the detected error. Optionally the data transfer unit may return the data transfer rate to the original data transfer rate or state after a predetermined time has elapsed, after a predetermined number of commands have been received, after a predetermined amount of data have been transferred, or by combination of these.
摘要:
An external controller performs a thorough analysis and prediction on true requests from an application to issue a look-ahead request to an HDD or other auxiliary storage. An HDC card is connected to an HDD device which stores data and has a cache memory. The HDC card, which controls the HDD device, includes an access request tracer for tracing a true access request made by an application program executed by a host directly from the application program, a speculation request determination section for determining a speculation request to be expected later based on the traced true access request, and an HDC for issuing the determined speculation request to the HDD device.
摘要:
In the case of magnetic head of magnetoresistance effect type whose breakdown voltage is as low as 0.3 V, it is impractical to ignore even a very small amount of static electricity that occurs during fabrication or use. In one embodiment, the desired magnetic head is produced by forming an SiO2 layer on a silicon slider, thereby forming an SOI substrate; forming on the SOI substrate circuits to protect a TMR element from overvoltage and a read-write circuit; forming field effect transistors from an Si semiconductor layer (formed by reduction of the SiO2 layer or epitaxial growth on the SiO2 layer); forming three electrodes (source, gate, drain) on the Si semiconductor layer; forming a Schottky diode by Schottky contact (metal) with the Si semiconductor layer; forming overvoltage protective circuits of aluminum wiring on the SOI substrate; and forming a TMR element.
摘要:
In the case of magnetic head of magnetoresistance effect type whose breakdown voltage is as low as 0.3 V, it is impractical to ignore even a very small amount of static electricity that occurs during fabrication or use. In one embodiment, the desired magnetic head is produced by forming an SiO2 layer on a silicon slider, thereby forming an SOI substrate; forming on the SOI substrate circuits to protect a TMR element from overvoltage and a read-write circuit; forming field effect transistors from an Si semiconductor layer (formed by reduction of the SiO2 layer or epitaxial growth on the SiO2 layer); forming three electrodes (source, gate, drain) on the Si semiconductor layer; forming a Schottky diode by Schottky contact (metal) with the Si semiconductor layer; forming overvoltage protective circuits of aluminum wiring on the SOI substrate; and forming a TMR element.
摘要:
A novel optical film is provided that exhibits a wavelength dispersion (a reverse wavelength dispersion) such that the birefringence of the film decreases as the wavelength becomes shorter, at least in the visible light range. The optical film includes a layer formed of a resin (A) having a heteroaromatic group or a molecular structure represented by the following formula (1), (2) or (3): where in the formula (1), n is a natural number in the range of 1 to 4, and R1 and R2 each independently represent a hydrogen atom or a methyl group. The optical film exhibits a wavelength dispersion such that the birefringence of the film decreases as the wavelength becomes shorter, at least in the visible light range.