support updating an existing sparse raw file like e2image -racp #267
Description
e2image -racp can be used to update an existing sparse raw file (make holes in sparse target if source are zeros)
from e2image doc
-c
Compare each block to be copied from the source device to the corresponding block in the target image-file. If both are already the same, the write will be skipped. This is useful if the file system is being cloned to a flash-based storage device (where reads are very fast and where it is desirable to avoid unnecessary writes to reduce write wear on the device).