| 摘要 |
PURPOSE:To process update requests by plural tasks in parallel and to efficiently restore data by stopping a process in a short period in the case of fault detec tion. CONSTITUTION:An update request by a task 1 to a block B1 is fetched (S9) and an update request by a task 2 to B1 is fetched (S10). Once the task 1 makes a commitment, update information (update journal, data before update, and data after update) determined by the S9 and S10 is saved in a magnetic disk device(MD). Then the update request by the task 1 is fetched (S14) and then the update request by the task 2 is fetched (S15). Once the task 2 makes a commitment 2, update information determined by S14 and S15 is saved in the MD. If a fault occurs here, the pieces of update information in the MD are stored in a corresponding storage area in a main storage device to enter the storage state at the time of the commitment 1 which is determined last time, and CPU processing is restarted. |
