Gordan Bobic <[email protected]> wrote: >If you are using an image, please make sure you do: > >dd if=/dev/zero of=/scrub bs=8MB; rm -f /scrub > >before you create the image to zero out the free space.
I wrote the zerofree utility for just this sort of thing. It looks for non-zero free blocks in an ext2/3/4 filesystem and zeroes them. Because it doesn't write to blocks that are already zeroed it can be more efficient than using dd. It only works on unmounted (or read-only) filesystems, though. My write-up on zerofree is here: http://intgat.tigress.co.uk/rmy/uml/sparsify.html For the terminally impatient: # e2fsck -f /dev/sdx1 # zerofree -v /dev/sdx1 # e2fsck -f /dev/sdx1 The -v flag shows progress and prints the number of blocks zeroed, total free blocks and total blocks at the end of the process. Use '-n -v' to perform a dry run to see if it's worth bothering to zero a given filesystem. It's available in the standard repositories for Fedora and Debian, plus EPEL for CentOS/RHEL 5, though not 6. I really ought to make an RPM for 6. Ron _______________________________________________ users mailing list [email protected] http://lists.redsleeve.org/mailman/listinfo/users
