| US 7,565,501 B2 | ||
| Storage controller and data management method | ||
| Katsuo Mogi, Odawara (Japan); Koji Nagata, Kaisei (Japan); Shoji Kodama, Sagamihara (Japan); and Ikuya Yagisawa, Machida (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
| Filed on Feb. 22, 2006, as Appl. No. 11/358,051. | ||
| Claims priority of application No. 2006-005580 (JP), filed on Jan. 13, 2006. | ||
| Prior Publication US 2007/0168629 A1, Jul. 19, 2007 | ||
| Int. Cl. G06F 12/00 (2006.01) | ||
| U.S. Cl. 711—162 [707/204] | 16 Claims |
| 1. A storage controller providing a volume for storing data transmitted from a host system, comprising:
a management unit for managing said data written into a first block area configured in said volume, or into a second block
area configured in said first block area which is smaller than said first block area;
a snapshot acquisition unit for acquiring a snapshot of said volume at a prescribed timing; and
a transfer unit for transferring said written data of said volume and said snapshot acquired by said snapshot acquisition
unit to an external device including a volume also configured with said first block area and said second block area to backup
said written data and said snapshot therein,
wherein data to be backed-up to the external device is transferred in a data size of the first or second block area depending
upon a size of said data,
said transfer unit transfers said data with said first block area when said data is not being managed with said management
unit in said second block area, and
when a total value of the areas of said second block area is greater than a prescribed threshold value, said management unit
deletes all areas of said second block area that it is managing.
|