Patent ID: 7100077
Filing Date: 2006-08-29
Classification: G06F

Abstract:
1. A backup method for requesting a backup system to back up files stored on a predetermined NAS of plural NASs in response to a backup request given from a client computer, comprising: selecting backup target files based on the backup request given from the client computer; allocating the selected backup target files respectively to the plural NASs: causing the respective NASs to request the backup system to back up the allocated backup target files in parallel; detecting an occurrence of a fault by monitoring the plural NASs from each other; taking over, when detecting that the fault has occurred, to another NAS the backup target files at or after a point of time when the fault occurred from within the backup target files of a fault-occurred NAS on which the fault occurred; causing the other NAS to request the backup system to back up the backup target files taken over; wherein the detecting the occurrence of the fault by monitoring the plural NASs from each other, comprises: setting counters associated respectively with the NASs; updating the counter corresponding to a file count of the files for which the backup request has been made, every time the backup request is given to the backup system; detecting a change in value of the counter; and judging, when there is no change in the counter value after a predetermined time has elapsed, that the fault has occurred on the NAS associated with the counter.