Smith: This approach installs a low-profile appliance into an IT storage infrastructure (the SAN) to capture and transmit copies of production data. Data is captured as it traverses the SAN from a host to storage, eliminating the need for host workload impacts, and for storage workload impacts. (One example of this is the Unisys SafeGuard solution which you can learn more about here.) A single deployment can protect a large number of hosts and a large number of disk storage subsystems. This minimizes the production impact of installing and maintaining data replication. This approach also allows different (mismatched) storage subsystems at production and disaster sites. The availability of out-of-band processing also allows the appliance to provide a rich feature set to manage the data replication flow. For example, Unisys's out-of-band appliance reduces the amount of wide-area network bandwidth required between a production site and the data replica at a disaster site -- typically by a factor of 10 or more -- and it does so without consuming host or storage cycles. It also retains before and after data images with the replica, enabling selected data rollback to any point in the past -- a real boon to recovering from unexpected data corruption at the production site.
Here are the chief advantages to an out-of-band data replication strategy:
- A single deployment to cover many hosts and many storage subsystems.
- The ability to mix and match different kinds of storage subsystems.
- Data protection with virtually no impact to production workloads.
- The ability to coordinate sync points in the data stream between different hosts and different storage subsystems.
- Superior bandwidth reduction to minimize wide area network link costs.
Out-of-band can be a very attractive approach to enabling protection of a complex environment, without having to disrupt the entire environment along the way.
InfoWorld: Thanks Norm. Needless to say, there are many factors to consider when considering your data replication strategy. Each environment will ultimately need to make the choices. Hopefully it's clear that choices must be made to ensure your company can continue to operate under the most extreme circumstances.
Are you prepared? I would like to know what you are doing to address these issues and which solutions you find beneficial for your particular environment.