Linux "zerofree" Command Line Options and Examples

zero free blocks from ext2, ext3 and ext4 file-systems

zerofree finds the unallocated, blocks with non-zero value content in an ext2, ext3 or ext4 filesystem (e.g. /dev/hda1) and fills them with zeroes (or another octet of your choice).

Usage:

zerofree [-n] [-v] [-f fillval] filesystem

Command Line Options:

-n

Perform a dry run (do not modify the file-system);


                            zerofree -n ...

-v

Be verbose: show the number of blocks modified by zerofree (or that would be modified, in case the


                            zerofree -v ...