Change Block Tracking CBT)
The “Storage Area Network” (SAN) is used for storing data on blocks which do not have a tag about their changing status sothat only a full backup could be performed. The “Change Block Tracking” (CBT) allows virtual machines to create an index for the blocks that they forward to the backup server. After changes, only the altered blocks need to be sent. The CBT may also be used to relocate larger databases within a VMFS-environment.