A redundant storage virtualization computer system is provided. The redundant storage virtualization computer system comprises a host entity for issuing an IO request, a redundant storage virtualization controller set coupled to the host entity for performing an IO operation in response to the IO request issued by the host entity, and a plurality of physical storage devices for providing storage space to the computer system. Each of the physical storage devices is coupled to the redundant storage virtualization controller set. The redundant storage virtualization controller set comprises a first and a second storage virtualization controller both coupled to the host entity, the storage virtualization controllers communicate therebetween via a PCI-Express interconnect. In the redundant storage virtualization controller set, a storage virtualization controller will take over the functionality originally performed by the alternate storage virtualization controller when the alternate storage virtualization controller is not on line.