Patent ID: 7234033
Filing Date: 2007-06-19
Classification: G06F

Abstract:
1. A processing system, comprising: a local site having a local host and a local storage system, the local storage system having a primary volume and receiving write data from the local host to the primary volume; at least two remote sites, each having a remote host computer and a remote storage system, each remote storage system including a mirrored volume of the primary volume for storing a copy of the write data; and a communication channel between the local storage system and at least one of the remote storage systems, the local storage system sending one or more commands to each of the remote storage systems to cause a copy of the write data to be stored on their respective mirrored volumes, each of the remote storage systems having one or more queues for queuing information used to produce the copy of write data, one of the remote storage systems communicating to another of the remote storage systems information relating to the queued information in order to identify differences between data images maintained by each of the mirrored volumes upon occurrence of a failure of the local storage system.