Replication is the practice of continually copying from a source system to a target system all files or blocks that have changed on the source system. Replication used to be what companies implemented after everything was completely backed up and redundant, which meant that few used replication. However, many people are now using replication as their first line of defense for providing backup and disaster recovery.
Newer products such as XOsoft make replication (and therefore disaster recovery) accessible and reasonable for companies of all sizes.
Replication advantages:
- easy to install and use
- hardware agnostic – you can replicate to heterogeneous systems
- provide failover capability
- have multiple methods of user and application redirect
- are VMware compatible
- work with databases and files – including Exchange
There are host-based replication products, hardware-based replication products (at the disk array level) and there are now a growing number of continuous data protection (CDP) products available.
The first step in selecting the right product for your organization is to clearly establish your business requirements (number of copies, retention, recovery time objectives, etc). When evaluating replication alternatives consider the following criteria:
- Distance between data source and destination (this will determine whether you can do synchronous or asynchronous replication. This will influence performance to various degrees.
- Features and functionality (i.e. how many point-in-time copies, block-or file-level replication, restore granularity, etc.).
- Ease of management—How user-friendly is the interface and what kind of training will be required (if any)?
- Cost (capacity-based versus host-based licensing should be compared).
- Scalability—This will depend on your anticipated future growth.
