Patent ID: 8527725

Claim:
A method for storing data in a clustered network comprising a first storage system including a first logical volume and a second storage system including a second logical volume in communication with the first storage system, the method comprising: receiving, at the second storage system, from a host a command to write data to the second logical volume; transmitting, by the second storage system, the command to the first storage system; writing, by the first storage system, the data to the first logical volume; transmitting, by the first storage system, a write permission to the second storage system; receiving, by the second storage system, the write permission; and writing, by the second storage system, the data to the second logical volume in response to receiving the write permission, wherein: the second storage system does not write the data to the second logical volume prior to receiving the write permission, and the first storage system writes the data to the first logical volume without permission.