Storage controller, storage system and storage control method
AssigneeFujitsu Limited
InventorKenji UCHIYAMA
Life of this patent
Estimating the term…
Abstract
A storage controller, when writing n sets of data into a first storage device, adds dummy data to other sets of data except for a first set of data having a largest size among the n sets of data such that sizes of other sets of data become equal to the size of the first set of data, calculates (n−1) parities based on the first set of data and the other sets of data, and when reading the n sets of data from the first storage device, concurrently performs a processing of reading a second set of data having a smallest size among the n sets of data from the first storage device and a processing of restoring each of two or more sets of data in the n sets of data except for the second set of data, by using the (n−1) parities and the dummy data.
Claims15
A storage controller comprising:
- a parity calculation unit that:
- when writing n sets of data (n is an integer of three or more) into a first storage device,
- adds dummy data to other sets of data except for a first set of data having a largest size among the n sets of data such that sizes of other sets of data become equal to the size of the first set of data,
- calculates (n−1) parities based on the first set of data and the other sets of data to which the dummy data is added, and
- stores the (n−1) parities into a second storage device;
- and
- a controller unit that:
- when reading the n sets of data from the first storage device,
- concurrently performs a processing of reading a second set of data having a smallest size among the n sets of data from the first storage device and a processing of restoring each of two or more sets of data in the n sets of data except for the second set of data, by using the (n−1) parities and the dummy data.
A storage system comprising:
- a first storage device;
- a second storage device;
- and
- a storage controller that:
- when writing n sets of data (n is an integer of three or more) into a first storage device,
- adds dummy data to other sets of data except for a first set of data having a largest size among the n sets of data such that sizes of other sets of data become equal to the size of the first set of data,
- calculates (n−1) parities based on the first set of data and the other sets of data to which the dummy data is added, and
- stores the (n−1) parities into a second storage device,
- when reading the n sets of data from the first storage device, and
- concurrently performs a processing of reading a second set of data having a smallest size among the n sets of data from the first storage device and a processing of restoring each of two or more sets of data in the n sets of data except for the second set of data, by using the (n−1) parities and the dummy data.
A storage control method comprising:
- when writing n sets of data (n is an integer of three or more) into a first storage device, using a computer,
- adding dummy data to other sets of data except for a first set of data having a largest size among the n sets of data such that sizes of other sets of data become equal to the size of the first set of data,
- calculating (n−1) parities based on the first set of data and the other sets of data to which the dummy data is added, and
- storing the (n−1) parities into a second storage device,
- when reading the n sets of data from the first storage device, using a computer,
- concurrently performs a processing of reading a second set of data having a smallest size among the n sets of data from the first storage device and a processing of restoring each of two or more sets of data in the n sets of data except for the second set of data, by using the (n−1) parities and the dummy data.
Dependencies are inferred from the claim text.