On Mon, February 8, 2016 3:37 pm, Digimer wrote:
Personally, I just do 'dd if=/dev/zero of=/path/to/zero.img bs=1M; rm -f /path/to/zero.img'. It's inelegant, for sure, but it works (note to run it as a normal user or else be careful of how your system reacts to running out of disk space for a moment).
This definitely does the trick. reallocated bad blocks aside, one path writing zeroes on modern drives is sufficient, according to one nice paper on the subject I remember. Does not comply DoD (and similar) secure data destruction though... As it always is when army is concerned: overkill ;-)
Valeri
fix-it-with-a-hammer-digimer
On 08/02/16 04:34 PM, Wes James wrote:
Is there a utility to zero unused blocks on a disk?
CentOS 6.7/Ext4
I saw zerofree, but Iâm not sure it would work on Ext4 or even work on this version of CentOS.
thanks,
-wes _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
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++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++