By Ann Silverthorn
—Tomorrow, Double-Take Software will launch two products based on a technology the company calls System State Protection and Recovery, which replicates the operating system, registry, drives, hot fixes, and patches—everything that makes up the server's identity—not just the data. In addition, it replicates applications and their settings.
The two new products—Double-Take ShadowCaster and Double-Take Server Recovery Option—are built on top of the company's replication technology and allow recovery to hardware that may be different than that of the production system. The new server doesn't need to be the same type or manufacturer. It can also be a virtual server.
ShadowCaster is a stand-alone product that provides a high-availability solution for Windows Small Business Server (SBS) 2003. It includes Double-Take Replication and addresses the need for SBS local fail-over, allowing cluster-like availability, something small businesses typically cannot afford. The ShadowCaster interface is simpler than the standard Double-Take interface, and the software performs all target maintenance, such as patches and security hot fixes, automatically. The company claims that in case of a production-system failure, fail-over to the target server can be completed in about 10 minutes.
Server Recovery Option (SRO) requires a Double-Take Replication license and combines continuous data replication with continuous system-state protection. It allows recovery from either a real-time image of the system or a snapshot image from a previous point in time.
SRO replicates multiple servers to a central disk-based repository. More a disaster-recovery product than a fail-over one, SRO is designed for servers that typically back up to tape. These are typically middle-tier servers that don't require real-time fail-over.
SRO also reportedly reduces recovery from a half day for tape backup to one hour (or from a full day to two hours). The software allows recovery from either a real-time image or a previous point-in-time image of the original server. The new server doesn't have to be the same hardware as the old. The only requirement is that the new server runs the same version of Windows.
Because SRO uses Double-Take Replication, it allows compression, bandwidth throttling, and scheduling, so the target server can reside in a separate location, unlike ShadowCaster, which requires a local target. SRO automates the recovery process—pushing Double-Take Replication plus the data, applications, and operating system of the production server to the new system.
SRO lists at $595 for each protected server, in addition to $2,870 for the standard edition of Double-Take's replication software. ShadowCaster pricing starts at $1,495.