Abstract: A method and apparatus for mirroring data stored in a storage device in a mass storage system by caching mirror coherency synchronization operation requests (break mirror and/or snapshot) from the operating system of a server and rapidly sending an acknowledgement to the server that the mirror operation has been completed. Thereafter, the mass storage system performs the flushing and mirroring processes to establish a mirror of the storage device at a time that is appropriate and convenient for the mass storage system to perform such mirroring. To facilitate such a mirror operation at a later time, the mass storage system may utilize a mirror table containing information concerning the mirror request. This information enables the mass storage system to subsequently flush the cache of data that is pertinent to a time before the mirror request occurred. Consequently, the mirror operation only mirrors data that would have been available for mirroring at the time the mirror request was received from the server.

Abstract: A system and method for recording and storing data such that in the event of a fault condition, a management file can be regenerated. This is accomplished by writing first management files, for managing time-sequential data, onto a recording medium. A second management file, which indicates recording positions and sizes on the recording medium, is also written onto the recording medium. A third management file, which manages all of the time-sequential data, is also written onto the recording medium. In the event of a fault condition, which may compromise the integrity of the third management file, a duplicate third management file can be generated based on the second management file.