In disk arrays, a business continuance volume, or BCV, is EMC Corporation's term for an independently addressable copy of a data volume, that uses advanced mirroring technique for business continuity purposes.
BCVs can be detached from the active data storage at a point in time and mounted on non-critical servers to facilitate offline backup or parallel processing. Once offline processes are completed, these BCVs can be either:
discardedre-attached (re-synchronized) to the production data againused as a source to recover the production dataThere are two types of BCVs:
A clone BCV is a traditional method, and uses one-to-one separate physical storage (splitable disk mirror)least impact on production performancehigh cost of the additional storagepersistent usageA snapshot BCV, that uses copy on write algorithm on the production volumeuses only a small additional storage, that only holds the changes made to the production volumelower cost of the additional storagereads and writes impact performance of production storageonce snapshot storage fills up, the snapshot becomes invalid and unusableshort-term usage