A system for optimizing storage operations by operating only on mapped
blocks may include a first and a second set of one or more storage
devices, a virtual device client and a virtual device server. The virtual
device server may be configured to aggregate storage in the first set of
one or more storage devices into a virtual storage device, and make the
virtual device accessible to the virtual device server. In preparation
for a synchronization operation, the virtual device server may obtain a
map identifying one or more in-use regions of the virtual storage device
from the virtual device client. The virtual device server may then
perform the synchronization operation by copying the one or more in-use
regions of the virtual storage device to the second set of one or more
storage devices.