Control apparatus, storage apparatus, and computer product
View Patent ↗Offtrack amounts corresponding to every servo in which data writing has been completed is stored in a storage unit. Offtrack amount corresponding to a next servo frame, which is a servo frame present next to a servo frame for which data has been written, is calculated from the offtrack amounts stored in the storage unit. Based on the offtrack amount of the next servo frame, it is decided whether data needs to be rewritten in a sector present before the next servo frame.
1. A control apparatus that controls a storage apparatus to rewrite data when a write fault occurs while the data is being written to a storage medium included in the storage apparatus, the control apparatus comprising:
a storage unit that stores therein an offtrack amount of a head of the storage apparatus when the head writes data in each servo frame on the storage medium using a plurality of servo frames recorded on the storage medium;
a calculating unit that calculates an offtrack amount corresponding to a next servo frame, which is a servo frame present next to a data-writing-complete servo frame for which the head has completed data writing, based on the offtrack amounts stored in the storage unit; and
a rewrite determining unit that determines, based on the offtrack amount of the next servo frame calculated by the calculating unit, whether the data needs to be rewritten in a sector located before the next servo frame.
2. The control apparatus according to claim 1 , further comprising a number-of-sectors determining unit that calculates number of sectors in which the data needs to be rewritten based on the offtrack amounts of the next servo frame and the data-writing-complete servo frame.
3. The control apparatus according to claim 2 , wherein the storage unit further stores therein an amplification degree by which a read signal read from each of the servo frames recorded on the storage medium is amplified to a predetermined output level, and
the number-of-sectors determining unit determines the number of sectors in which the data is to be rewritten based on the offtrack amounts and the amplification degree.
4. A storage apparatus that rewrites data when a write fault occurs while the data is being written to a storage medium included in the storage apparatus, the storage apparatus comprising:
a storage unit that stores therein an offtrack amount of a head of the storage apparatus when the head writes data in each servo frame on the storage medium using a plurality of servo frames recorded on the storage medium;
a calculating unit that calculates an offtrack amount corresponding to a next servo frame, which is a servo frame present next to a data-writing-complete servo frame for which the head has completed data writing, based on the offtrack amounts stored in the storage unit; and
a rewrite determining unit that determines, based on the offtrack amount of the next servo frame calculated by the calculating unit, whether the data needs to be rewritten in a sector located before the next servo frame.
5. The storage apparatus according to claim 4 , further comprising a number-of-sectors determining unit that calculates number of sectors in which the data needs to be rewritten based on the offtrack amounts of the next servo frame and the data-writing-complete servo frame.
6. The storage apparatus according to claim 5 , wherein the storage unit further stores therein an amplification degree by which a read signal read from each of the servo frames recorded on the storage medium is amplified to a predetermined output level, and
the number-of-sectors determining unit determines the number of sectors in which the data is to be rewritten based on the offtrack amounts and the amplification degree.
7. A computer-readable recording medium that stores therein a computer program that causes a computer to rewrite data when a write fault occurs while the data is being written to a storage medium included in a storage apparatus, the computer program causes the computer to execute:
storing in a storage unit an offtrack amount of a head of the storage apparatus when the head writes data in each servo frame on the storage medium using a plurality of servo frames recorded on the storage medium;
first calculating including calculating an offtrack amount corresponding to a next servo frame, which is a servo frame present next to a data-writing-complete servo frame for which the head has completed data writing, based on the offtrack amounts stored in the storage unit; and
determining, based on the offtrack amount of the next servo frame calculated by the calculating unit, whether the data needs to be rewritten in a sector located before the next servo frame.
8. The computer-readable recording medium according to claim 7 , wherein the computer program further causes the computer to execute second calculating including number of sectors in which the data needs to be rewritten based on the offtrack amounts of the next servo frame and the data-writing-complete servo frame.
9. The computer-readable recording medium according to claim 8 , wherein the storing further includes storing in the storage unit an amplification degree by which a read signal read from each of the servo frames recorded on the storage medium is amplified to a predetermined output level, and
the second calculating includes calculating the number of sectors in which the data is to be rewritten based on the offtrack amounts and the amplification degree.