A delta disk backing is a way to preserve a virtual disk backing at some point in time. A delta disk backing is a file backing which in turn points to the original virtual disk backing (the parent). After a delta disk backing is added, all writes go to the delta disk backing. All reads first try the delta disk backing and then try the parent backing if needed.
Promoting does two things
If the unlink parameter is true, the net effect of this operation is improved read performance, at the cost of disk space. If the unlink parameter is false the net effect is improved read performance at the cost of inhibiting future sharing.
This operation is only supported if VcHostCapability is true.
This operation is only supported on VirtualCenter.
|unlink||boolean||If true, then these disks will be unlinked before consolidation.|
|disks||VcVirtualDisk||The set of disks that are to be promoted. If this value is unset or the array is empty, all disks which have delta disk backings are promoted.|