JOURNAL LOG CONTROL SYSTEM, JOURNAL LOG CONTROL METHOD, AND JOURNAL LOG CONTROL PROGRAM

摘要

To improve writing performance in a file system by securing consistency of both of file system data and metadata when an error has occurred by using journaling and reducing writing volume associated with the journaling.SOLUTION: A permanent memory 200 stores data, metadata, and a journal log being an update history of the data and the metadata. When writing is requested, a journal log control unit 110 controls execution of a journaling process of storing data related to the writing request and update history of meta data into the journal log, a commitment process for fixing the update history stored in the journal log, a check point process for reflecting the fixed update history stored in the journal log to the data and the meta data, and a delayed checkpoint process for delaying the checkpoint process.SELECTED DRAWING: Figure 1