Disclosed is a storage virtualization subsystem (SVS) architecture comprising a plurality of SVSs, each SVS comprising at least one storage virtualization controller (SVC), and, in some cases, a physical storage disk (PSD) array attached to the SVC. A first and a second data access path is configured passing through the SVSs to form the SVS architecture such that when one path is failed, the other can be taken as a substitution. The SVSs in the first path are connected in a first sequence and the SVSs in the second path are connected in a second sequence different from the first one. In another embodiment, each SVS comprises a plurality of redundantly-configured SVCs rather than one SVC. The first path is formed passing through a first set of SVCs and the second path is formed passing through a different second set of SVCs.