On Fri, 7 Dec 2012, Chuck Burns wrote: > dd if=/dev/zer of=/dev/ada0 > > ^^^ There's your "badblocks" program. Any hard drive made in the last decade > have been self-remapping.. That should be /dev/zero. And this will be very slow, going one 512-byte block at a time. Using a 64K or 128K buffer (bs=128K) will speed it up tremendously.