If you did not enable reverse protection, your source is a domain controller, or if you have to rebuild your source, you have two options after a failover. You can continue running from the failed over server indefinitely. This server is your source (running on the original target hardware) and you can protect it to a new target. Your other option is to go back to the original hardware. Without reverse protection, you have to complete this process manually, which can be difficult.
Preparation of your original source hardware or a new server is key to this manual process. The type of preparation required will depend on the role of the original source server, the applications that were used on the original server, whether the original source was a physical or virtual server, and the failure or event that occurred.
New virtual guest—If your original guest is unusable, start with 1A. Preparing a new server by reinstalling Windows and then continue with the remaining instructions.
If possible, you can attach any virtual hard disks that survived the failure event to a new virtual guest. Reusing any undamaged disks will decrease the time required to restore data because you can use a difference mirror.
As an alternative to manually creating a new virtual guest, you can let Double-Take automatically provision (create) the new virtual guest for you. If you choose this option, you will need to use the instructions Creating a full server to ESX job or Creating a full server to Hyper-V job instead of the instructions in this section.