What? You Want Replications With That?

Data replication can play a key role in assuring data availability and recovery for networked storage. Replication in the form of data snapshots as well as full site-to-site mirroring can be achieved via three methods:

• Host Based. Software running on the host servers manages volume copying and replicates storage writes.
• Array Based. Replication is done by software running on a disk array controller.
• Network Based. Replication is managed on the network either through software on a “smart” switch or via network attached appliance or server.

This note looks at the relative pros and cons of each approach to replication as well as the current state of the market in terms of vendor offerings.