Patent ID: 7152078

Claim:
A method of backup and restore procedure using a first storage subsystem and second storage subsystem which are connected to each other via a path, the first storage subsystem connected to a first host, the second storage subsystem connected to a second host, the method comprising the steps of: performing a backup procedure comprising the steps of: providing a first logical volume in the first storage subsystem and a second logical volume and a third logical volume in the second storage subsystem, the second logical volume being a copied logical volume of the first logical volume, the first and second logical volumes being in sync state, the third logical volume being a copied logical volume of the second logical volume, the second and third logical volumes being in sync state; and splitting the second logical volume and the third logical volume by a command sent by the first storage subsystem; and performing a restore procedure comprising the steps of: mounting the third logical volume to the second host, receiving an indication of an individual file to be restored, reading, at the second host, the file to be restored from the third volume, writing, at the second host, the file to the second volume, and re-synchronizing the first volume with the second volume.