Patent ID: 7139932

Claim:
A storage system comprising: a local storage system having at least a first storage volume for storing data; a remote storage system having at least first and second remote storage volumes for storing data; and a communication link between the local storage system and each of the first and second remote storage volumes, wherein the at least first local storage volume is mirrored to at least the first remote storage volume, wherein upon detecting an interruption in communications between the local storage system and the first remote storage volume: a first record of the changes made to the first local storage volume from the time of the interruption is created and stored on the first local storage volume, the first record thereafter being updated with changes to the first local storage volume made subsequent to the interruption; a second record of the changes made to the first remote storage volume from the time of the interruption is created and stored on the first remote storage volume; and a copy of the first record is provided to the second remote storage volume, wherein the first remote storage volume and the second remote storage volume can be resynchronized based on the second record stored on the first remote storage volume and on the copy of the first record stored on the second remote storage volume.