Patent ID: 6701455
Filing Date: 2004-03-02
Classification: G06F,Y10S

Abstract:
A method for providing data integrity in a storage system having a local storage unit including local data storage media and a remote storage unit including remote data storage media, the local storage unit being coupled to the remote storage unit by a communications link, the method comprising:providing at least one additional remote data storage media in the remote storage unit; upon interruption of the communications link: maintaining a first record of transactions which have been stored in the local data storage media and have not yet been stored in the remote data storage media; copying data from the remote data storage media to the additional remote data storage media, and maintaining a second record of the data copied to the additional remote data storage media; upon restoration of the communications link: using the first record of transactions to determine which transactions have not been written to the remote storage unit, and sending those transactions to the remote storage unit; and in the remote storage unit comparing the transactions received from the local storage unit to the second record and writing new transactions into the additional remote data storage media.