similar to: Utility to zero unused blocks on disk

On Mon, Feb 8, 2016 at 3:18 PM, <m.roth at 5-cent.us> wrote: > Chris Murphy wrote: >> DBAN is obsolete. NIST 800-88 for some time now says to use secure erase >> or enhanced security erase or crypto erase if supported. >> >> Other options do not erase data in remapped sectors. > > dban doesn't? What F/OSS does "secure erase"? And does it do

On 2/8/2016 9:54 PM, Chris Murphy wrote: > Secure erase is really the only thing to use on SSDs. Writing a pile > of zeros just increases wear (minor negative) but also doesn't > actually set the cells to the state required to accept a new write, so > you've just added a lot more work for the SSD's garbage collector and > wear leveling, so it's going to be slower

> -----Original Message----- > From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On > Behalf Of EGO-II.1 > Sent: den 9 februari 2016 09:00 > To: CentOS mailing list > Subject: Re: [CentOS] Utility to zero unused blocks on disk > > > > >> the only truly safe way to destroy data on magnetic media is to grind > >> the media up into

DBAN is obsolete. NIST 800-88 for some time now says to use secure erase or enhanced security erase or crypto erase if supported. Other options do not erase data in remapped sectors. Chris Murphy

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). 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? >

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

On 2/8/2016 2:14 PM, Chris Murphy wrote: > DBAN is obsolete. NIST 800-88 for some time now says to use secure erase or > enhanced security erase or crypto erase if supported. > > Other options do not erase data in remapped sectors. the only truly safe way to destroy data on magnetic media is to grind the media up into filings or melt it down in a furnace. -- john r pierce,

Chris Murphy wrote: > DBAN is obsolete. NIST 800-88 for some time now says to use secure erase > or enhanced security erase or crypto erase if supported. > > Other options do not erase data in remapped sectors. dban doesn't? What F/OSS does "secure erase"? And does it do what dban's DoD 5220.22-M does? mark, overkill

On 2/8/2016 3:33 PM, Valeri Galtsev wrote: > DRAM had more persistent imprint of information that was sitting in it, > which appears much harder to destroy than information on hard drive. well aware of that. 30 years ago a friend and I built a specialized video card for a consulting project.... discovered on the prototype that we could power it down, go home, come back the next day,

On 02/08/2016 03:05 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. Wes didn't say the reason he wanted to zero

Once upon a time, Greg Bailey <gbailey at lxpro.com> said: > Wes didn't say the reason he wanted to zero unused blocks, but I > always do this in kickstart scripts when constructing VM images as > the image size is considerably reduced by doing this... For that purpose, use something that can TRIM a VM image, like virt-sparsify. -- Chris Adams <linux at cmadams.net>

On 02/08/16 15:34, 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. > > thanks, > . a comment on replies to your post. i find it interesting that "Subject:" is and you ask for info to *zero unused blocks on disk*

On 02/08/2016 07:04 PM, Chris Adams wrote: > Once upon a time, Greg Bailey <gbailey at lxpro.com> said: >> Wes didn't say the reason he wanted to zero unused blocks, but I >> always do this in kickstart scripts when constructing VM images as >> the image size is considerably reduced by doing this... > > For that purpose, use something that can TRIM a VM image,

On 02/08/16 23:10, Digimer wrote: > On 09/02/16 12:08 AM, g wrote: >> >> >> On 02/08/16 15:34, 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. >>> >>>

On 02/08/2016 07:38 PM, Always Learning wrote: > On Mon, 2016-02-08 at 14:22 -0800, John R Pierce wrote: > >> the only truly safe way to destroy data on magnetic media is to grind >> the media up into filings or melt it down in a furnace. > I unscrew the casing, extract the disk platter(s), slide a very strong > magnet over both sides of the platter surface then bend the

On 09/02/16 12:24 AM, g wrote: > > > On 02/08/16 23:10, Digimer wrote: >> On 09/02/16 12:08 AM, g wrote: >>> >>> >>> On 02/08/16 15:34, 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

On 02/08/16 23:39, Digimer wrote: > On 09/02/16 12:24 AM, g wrote: <<>> >> fell better? :-P > > I need ice cream to feel better. ;) > . Baskin-Robbins 32 flavors + special of month. -- peace out. If Bill Gates got a dime for every time Windows crashes... ...oh, wait. He does. THAT explains it! -+- in a world with out fences, who needs gates. CentOS GNU/Linux

On 2/9/2016 12:42 AM, g wrote: > On 02/08/16 23:39, Digimer wrote: > > > >I need ice cream to feel better.;) > > > . > Baskin-Robbins 32 flavors + special of month. After seeing Aaron Neville tonight (wow, what a show, 3rd row center seats in a small theater, we were 15' from the stage), we stopped at The Penny Ice Creamery, and I had a small cone of Meyers Lemon

On 09/02/16 12:08 AM, g wrote: > > > On 02/08/16 15:34, 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. >> >> thanks, >> > . > a comment on replies to your post. > > i find

On Mon, 2016-02-08 at 14:22 -0800, John R Pierce wrote: > the only truly safe way to destroy data on magnetic media is to grind > the media up into filings or melt it down in a furnace. I unscrew the casing, extract the disk platter(s), slide a very strong magnet over both sides of the platter surface then bend the platter in half. How secure is that ? I can't afford a machine that