hdparm supports ATA secure erase. This is SSD safe, unlike other options. It's faster than writing zeros to both HDD and SSD. Chris Murphy On Mon, Feb 8, 2016, 3:06 PM <m.roth at 5-cent.us> wrote: > Wes James wrote: > > Is there a utility to zero unused blocks on a disk? > > > > CentOS 6.7/Ext4 > > > > I saw zerofree, but I’m not sure it would work on Ext4 or even work on > > this version of CentOS. > > > I don't understand the point of doing this. If you want to sanitize the > disk, use dban <dban.org>, which surely approaches industry standard for > the open source answer. > > Just zeroing random blocks? Why? If you want to wipe a specific file, > there's shred. > > mark > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >