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Storage Virtualization | FAQs & Discussions

Implementing Synchronous Data Mirroring Between FC SANs Using iSCSI Over Standard IP

Synchronous Data Mirroring is an excellent means to achieve combined Business Continuity and Disaster Recovery. Until recently, Synchronous Mirroring was reserved as a premium feature offered only on high-end SAN storage arrays. The proliferation of storage vendors and ultimate commoditization of storage hardware has somewhat changed that rule, and Synchronous Mirroring options are now found on the upper end of the mid-range market.

Synchronous Data Mirroring — An Overview

Synchronous Mirroring is, in effect, an implementation of RAID-1 with the implication that the mirrored "disks" are physically separated, either across the building, across campus or across geographies. The data is written to both disks or volumes at once, before the write acknowledgement is returned to requester. The principle idea is that at any given moment, the failure of a disk will not result in a loss of any data.