High availability and low capacity thin provisioning data storage system

摘要

A data storage system and method for simultaneously providing thin provisioning and high availability. The system includes external storage volume and two storage subsystems coupled together and to external storage volume. Each of storage subsystems includes disk drives and a cache area, each of the storage subsystems includes at least one virtual volume and at least one capacity pool. The virtual volume is allocated from storage elements of the at least one capacity pool. The capacity pool includes the disk drives and at least a portion of external storage volume. The storage elements of the capacity pool are allocated to the virtual volume in response to a data access request. The system further includes a host computer coupled to the storage subsystems and configured to switch input/output path between the storage subsystems. Each of the storage subsystems is adapted to copy received write I/O request to other storage subsystems. Upon receipt of request from another storage subsystem, storage element of the capacity pool of storage subsystem is prevented from being allocated to the virtual volume of that storage subsystem.