zerofree:
zerofree: Zerofree finds the unallocated, non-zeroed blocks in an ext2, ext3,
zerofree: or ext4 filesystem and fills them with zeroes. This is useful if the
zerofree: device on which this file-system resides is a disk image. In this
zerofree: case, depending on the type of disk image, a secondary utility may be
zerofree: able to reduce the size of the disk image after zerofree has been run.
zerofree:
zerofree: Homepage: https://frippery.org/uml/
zerofree:
zerofree: