physical data replication

An on-line data replication method that duplicates I/O writes to another disk on a physical block basis. Physical replication can be hardware-based where data is replicated between disks over a dedicated link (e.g. EMC's Symmetrix Remote Data Facility or the HP StorageWorks E Disk Array XP Series Continuous Access), or software-based where data is replicated on multiple disks using dedicated software on the primary node (e.g. MirrorDisk/UX).