Originally posted by: Christophe
A first line of protection can be local or in-system replication, a process that copies volumes of data internal to the storage array. This allows customers to leverage point in time copies for a variety of needs, the scope of which is well beyond data recovery and includes business reasons such as; i) change/control, ii) maintenance, iii) use by other applications for analytical purposes and more. More importantly, using a local full volume copy on a cyclical basis also protects users from data corruption, allowing them to revert back to an uncorrupted version of their data. This is a critical function for some mission-critical applications, such as email and high transactional OLTP applications for example.
If site-wide events occur however, data assets are exposed to destruction. To mitigate this risk, replicating data over a certain distance is the answer. Two remote replication modes traditionally used are i) synchronous remote replication and ii} asynchronous remote replication.