Preserving the disaster copy virtual machine
The disaster copy virtual machine should only be manually powered on through the virtualization server in the case of an actual disaster. Once powered on, the operating system present in the disaster copy will modify its disk, and incremental virtual machine restores will no longer be possible after this point.
IMPORTANT: If a test of the disaster copy is required, clone the disaster VM to another location and use that copy for testing. If the disaster copy has already been used for testing purposes, and then an actual disaster occurs, the disaster copy may have already been altered during testing and no longer be suitable as a disaster copy.