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: