Mirroring data

Make sure you have a valid source and target specified, click Configure protection from the main Full-Server Failover Manager page, and then select the Advanced tab.
Specify how you want to mirror data.

Mirroring—Select the type of Double-Take Availability mirroring process you want to perform. A Full mirror will transmit all files from the source to the target. A Checksum mirror will transmit only the blocks of data that are different between the source and target.
Estimate Replication Set size based on volume—The size of the replication set is used to determine mirroring remaining calculations. If this option is enabled, the replication set size is based on the volume size, which is a faster calculation. If disabled, the replication set size is based on the selected data, which can be a slower calculation. The mirror will remain in an initializing state until the calculation is complete.