Messages in this thread | | | Date | Wed, 13 Feb 2002 10:27:41 -0800 | From | Mike Fedyk <> | Subject | Re: secure erasure of files? |
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On Wed, Feb 13, 2002 at 10:33:33AM +0100, Helge Hafting wrote: > Andreas Ferber wrote: > > > I don't know if any filesystem currently relocates blocks if you > > overwrite a file, but it's certainly possible and allowed (everything > > else except the filesystem itself simply must not care where the data > > actually ends up on the disk). > > > A log-structured fs will write new blocks everytime, afaik.
Ext3 only does that on truncate in ordered/writeback mode and probably in data journaling mode too.
> Ext3 with data journalling keeps copies of recently written data > in the journal. Now, if you create a "secret" file and then overwrite > it you'll still find a copy in the journal until the journal wraps > It may not wrap if the next thing you do is umount/shutdown. > > A secure rm must know the fs it works with. A better solution > is to overwrite the entire partition with garbage. The only > perfect way is to destroy the magnetic surfaces though. >
Yep, very true.
Phycally breaking the drive apart into pieces and then burning should suffice.
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