zerofree command finds the unallocated, non-zeroed blocks in an ext2 or ext3 file-system and fills them with zeroes
A NTFS Windows machine, with a mechanical drive, was upgraded from 7 to 10. The drive is old and I suspect that much of the free space actually has data and not filled with zeros.
Is it possible (how?) to zero out the free space, so that when an image is created, the size is minimal?
Assume either a bootable USB configured with Ubuntu or SysRescueCD is available to process the HDD by mounting the NTFS partion with
NTFS-3G if necessary
Go to Source