What type of replication ensures that all data copies are synchronized across primary and remote storage?

Synchronous replication is designed to ensure that all data copies are kept in perfect alignment across both primary and remote storage locations. This method creates an exact duplicate of data in real-time, meaning that any changes made to the primary data are simultaneously applied to the remote copy. As a result, both the primary and secondary sites always reflect the exact same data state at any given moment.

This approach is crucial for applications that require high availability and immediate data consistency, such as transactional systems where even minor delays or discrepancies could lead to data integrity issues. By using synchronous replication, organizations can mitigate risks associated with data loss, as retrieval from the secondary site yields fully up-to-date information.

In contrast, asynchronous replication does not ensure the same immediate data consistency because it allows changes to be written to the primary storage first, and then asynchronously sends those changes to the remote site later, which could cause temporary mismatches. Incremental replication focuses on transferring only the changes made since the last replication, rather than ensuring real-time synchronization, while partial replication involves only a subset of data being replicated rather than the entirety, further negating the condition for full synchronization across all copies.