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itsbrad212 03-10-2010 02:58 PM

Quote:

Originally Posted by penguiniator (Post 3893319)
rm deletes a file permanently. It is sent into oblivion.

Or move them to /dev/null :)

And sorry about my double post earlier in this thread. I accidentally hit the post button twice :P

jamescondron 03-10-2010 02:59 PM

Blimey, don't move them to /dev/null. You write to it, a mv will replace /dev/null

penguiniator 03-10-2010 04:07 PM

Quote:

Originally Posted by jamescondron (Post 3893329)
Not quite. Scrub perhaps, but not rm.

Well, yes. My point was that rm should be used with extreme caution. There is no simple undelete command to restore rm'd files.

jamescondron 03-10-2010 04:13 PM

Code:

root@jcmain:~# apt-cache search undelete
e2undel - Undelete utility for the ext2 file system
ntfsprogs - tools for doing neat things in NTFS partitions from Linux
magicrescue - recovers files by looking for magic bytes
recover - Undelete files on ext2 partitions


penguiniator 03-10-2010 04:18 PM

Are we all using ext2 these days? I'm certainly not.

jamescondron 03-10-2010 04:20 PM

Wow, I don't know how to answer that...

Ext3 and Ext4 are just the journalling versions of ext2; they're both ext2.

penguiniator 03-10-2010 04:23 PM

And reiserfs, etc.? You cannot count on having an easy time of undeleting files on any filesystem. That's my point.

jamescondron 03-10-2010 04:27 PM

Well, you can always go into Data Carving, which is a bit of a tarpit, though useful. There are many forensics tools out there that does this. That being said, I think a reiser partition is an extremely rare thing to find nowadays; lets face it, it was never that good.

And its hardly going to be improved, what with the designer's *ahem* legal problems.

penguiniator 03-10-2010 04:37 PM

Also, its unlikely the op is using ext2. He's using Mac OS X.

jamescondron 03-10-2010 04:39 PM

Well quite, but wasn't the matter being discussed whether or not rm sends a file into oblivion or not?

penguiniator 03-10-2010 04:44 PM

In the context of Mac OS X's file system. Yes. And of course, even there files can be undeleted. But without advanced preparation, it is still not guaranteed to be a simple operation.

jamescondron 03-10-2010 04:50 PM

Well in which case the shorter version of all of this is that it in fact sends it nowhere, and certainly not oblivion. Data carving, high end magnetic force microscopes, image analysis or a lot of high end equipment will bring, if not all, a fair chunk of the data back.

And as drives get larger and filesizes stay the same, similar or, thanks to better compression, smaller it'll get less and less likely that you'll sufficiently overwrite your files.

Which is great news for Forensics people, and also a good money spinner.

penguiniator 03-10-2010 04:52 PM

Yeah, that's simple and easy.

fbsduser 03-10-2010 04:55 PM

Quote:

Originally Posted by jamescondron (Post 3893432)
Well, you can always go into Data Carving, which is a bit of a tarpit, though useful. There are many forensics tools out there that does this. That being said, I think a reiser partition is an extremely rare thing to find nowadays; lets face it, it was never that good.

And its hardly going to be improved, what with the designer's *ahem* legal problems.

Maybe reiserfs is currently abandoned (it could get picked by someone else, it's opensource after all) but there are two other filesystems for linux that are in active development and aren't in the ext* family. Those are xfs and jfs, can you point to undeletion tools for them?

jamescondron 03-10-2010 05:05 PM

reiserfs probably wont be picked up, it took a lot of flack when it was in active development, xfs and jfs I don't know about; I'm pretty sure there is no undelete to recover paths/inode data but once again forensic techniques abound. Foremost has excellent results on xfs; jfs I've never looked at, though it seems stupid to assume that foremost wont have similar results.

@penguiniator:
There is an old phrase I remember reading in a Dawkins book, I can't remember who he attributes it too, and I dare say it doesn't matter; "Just because you don't understand doesn't mean I can't". I'm not saying these things are easy, though they're not as hard as I think you think they are (count the recursion..), and this was never a case of ease or difficulty.

You said the files get sent to oblivion. They don't. They get set as free/blank space, and as such can be recovered. Nothing more or less. I'm sorry if you've taken this as a personal insult or challenge, it certainly wasn't supposed to be, merely clearing up a misconception that, even if you yourself don't have, comments such as that lead other people to.


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