Unusual Question

Matthias Apitz guru at unixarea.de
Mon Jul 10 05:22:47 UTC 2017

El día domingo, julio 09, 2017 a las 05:34:06p. m. -0700, Doug Hardie escribió:

> >> but it gives an not permitted error.  The whole thing can crash and
> >> burn at the end.  This is an unmanned site so moving drives is not viable.
> >> _______________________________________________
> Thanks for the info.  I've never tried the rm approach, but the dd approach seems to work.  After a couple hours the machine became unresponsive and ssh sessions were terminated.  I think the drive is now empty.  I'd like to be able to get it back to verify, but that won't happen.  I still have 3 more systems to do this to.  The others will have to wait for awhile as I may still need them for a few more days.

I do not think that this approach worked in the sense of overwriting all
blocks of the disk. While walking through at some point the kernel will
miss sectors of the disk, for example of memory mapped files of shared
libs of other running processes or swapped out memory to disk. And the kernel
will just crash or halt and you will notice that as terminating ssh session.
Do not rely on the fact that the (sensitive) information on the disk was
overwritten. The only secure way is doing this from a system running on
some other disk and even this would allow to recover information with
forensic tools reading beside of the tracks. Only physical destruction
will help, for example burning the thing, as you said.


Matthias Apitz, ✉ guru at unixarea.de, ⌂ http://www.unixarea.de/  ☎ +49-176-38902045
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8 de mayo de 1945: Quien no festeja perdió la Guerra.
May 8, 1945: Who does not celebrate lost the War.
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