[CentOS] Utility to zero unused blocks on disk

[Chris Murphy]

On Mon, Feb 8, 2016 at 10:54 PM, Chris Murphy <lists at colorremedies.com> wrote:
> Secure erase is really the only thing to use on SSDs.

Oops. It's probably a fairly close approximation to just mkfs.btrfs -f
(or xfs) the entire block device for the SSD. If the kernel sees it as
non-rotational, it'll issue a whole device trim first, then write out
scant amount of metadata (btrfs writes out a tiny amount of metadata
at mkfs time, xfs a bit more, ext4 a lot and then even more after
mounting).

For most people this is probably a lot easier than the multistep
process using hdparm and secure erase.

-- 
Chris Murphy