Delta Vmdk -

Instead of modifying the original flat VMDK file, VMware freezes the parent disk and creates a new, sparse file (the delta). All new writes go to this delta file. Reads, however, must check both the delta (for recent changes) and the parent (for unchanged data).

In the world of VMware virtualization, the Virtual Machine Disk (VMDK) file is the primary container for a virtual machine's hard drive. However, when you take a snapshot, clone a VM, or use linked clones, you encounter a special type of file: the Delta VMDK . What Is a Delta VMDK? A Delta VMDK (often seen with the -delta.vmdk suffix) is a difference disk . It records only the changes made to the original parent VMDK disk since a specific point in time. delta vmdk