Disaster Recovery Options Replication & Deduplication

Data replication involves data being replicated and sent across your Wireless Area Network (WAN) to a remote disaster recovery location. Replication is scheduled for a certain time every day and automatically backed up to your remote server.

Data deduplication is the process of backing up data by eliminating redundancies. With data deduplication, only one unique instance of data is retained, meaning that every subsequent instance of that piece of data is referenced back to the one saved copy.

Data deduplication is beneficial for both replication and tape backup. With replication, it reduces replication time and bandwidth, improving recovery point objective (RPO) and recovery time objective (RTO) at the disaster recovery site with increased replication frequency. With tape backup, the increase of data retention on disk may result in lower frequency of tape copies and less tapes being stored off-site.

A more sophisticated version of replication is synchronous replication. This is a technique for replicating data between databases (or file systems) where the system being replicated waits for the data to be recorded on the duplicate system before proceeding. The synchronous replication approach requires access to all slave databases and 100% network availability for the replication to be successful. Therefore, network managers have to plan for synchronous replication and ensure that network availability is sufficient.

With synchronous replication, you have the guarantee that the duplicate system has a copy of the data, but the disadvantages that the primary system must wait for the secondary system before proceeding and replication will not be completed without high network availability.

Synchronous replication is currently the most sophisticated and costly form of data backup.

Coming next Wednesday in our Disaster Recovery series: Virtualization.