‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Friday, September 24, 2021 1:40 PM, Eric Blake <ebl...@redhat.com> wrote:
> On Fri, Sep 24, 2021 at 12:30:48PM +0000, Evan Greenup wrote: > > > +1 Here, > > If shred can support shredding directory tree recursively, it would be > > awesome. > > It can't, because that's not how shred works. Recursively shredding > files within a larger filesystem does NOT guarantee that the old file > is wiped out, because modern file systems tend to write the new file > to a different part of the block storage while leaving the old storage > unchanged other than marked as unused; with the right software, it's > fairly trivial to read the contents of those areas of the disk. On an > even more fundamental level, SSD disks tend to use wear-leveling > technology, where the hardware itself will dynamically reroute writes > to the same logical address to different portions of the storage over > time, again leading to hardware still containing old data that was not > overwritten. If you are not shredding an entire disk, chances are you > are not actually shredding the old data from the storage. Adding a > recursive option to shred to visit a series of files (rather than an > entire block device) would give users a false sense of security, so we > are unlikely to do it. Could it work on a specific partition? > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ > > On Friday, September 24th, 2021 at 9:06 PM, jedenfalco via GNU coreutils > > General Discussion coreutils@gnu.org wrote: > > > > > I have a laptop and want to securely wipe the hard drive. It would be > > > good to be able to wipe out an directory tree (e.g. /home) but it seems > > > that dd can only wipe an entire drive. > > > This means that I have to remove the hard drive and connect it externally > > > to another PC to wipe it. > > No need to unplug the hard drive, when you could instead boot your > computer from a live USB stick with a minimal operating system that > contains enough software to perform the shredding of your unmounted > hard drive. You may have to tweak BIOS/UEFI settings to be able to > boot from live media instead of from the hard drive, but that's still > easier than moving the hard drive to a different PC. > You are right. Wanted to avoid moving the hard drive to a different PC to do this thing.
