How to roll back and replicate a Windows server

Best known for its data replication technology, Double-Take Software has jumped into the snapshot business by adding the ability to replicate system state as well. It said that its Server Recovery Option allows it to recover an entire Windows server either to a real-time image or to a snapshot of its state at any time in the past.

It can even restore the system image to non-identical server hardware, something which differentiates it from many of its snapshot and replication competitors.

The ability to roll the system back to an earlier state is useful for reversing unwanted changes, such as viruses, data corruption and accidental file deletion, the company said. It also avoids the complex task of restoring from tape, a task made much harder if the backup must be restored to different hardware - and because you can roll back to just before the problem occurred, you don't automatically lose all data entered since the last full system backup.

"Data protection should really be about recoverability - making it easy to return to normal operations quickly, regardless of the circumstances," said Bob Roudebush, Double-Take's solutions engineering director.

The company has also used its replication technology to develop what it claimed is the first high availability solution for Windows SBS (Small Business Server). Called ShadowCaster, this continuously replicates the main SBS server to a secondary machine, with the latter taking over if the main server fails. Again, the two servers don't have to be identical.

"What impressed us the most is that ShadowCaster can run on two different servers," said Jeff Reynolds, the MIS manager at Alaska Tanker Company and a Double-Take user. "Competing products require the redundant server to be identical to the subject server."®