Running with / and /home on ext3. Can I switch to ext2? How can I do it without screwing things up? Thanks

Don't know why you'd want to, but the journal can be removed (and re-added) with tune2fs.
The ext2 utilities are used for ext3 as well.

Google is your friend.


The major difference between ext3 and ext2 is that ext3 has a journal. Why are you switching?

I was told that ext2 is more secure for deletions. I installed "bcwipe", which is supposed to be able to securely delete/overwrite the hard drive and files for ext3, but I was told to be sure that everything is gone that I should switch to ext2 then use the program. I have checked my hard drive with magicrescue for files I have deleted with "bcwipe", and nothing could be located after a 35x overwrite. Think I'm safe? Or should I change to ext2.

Google, just google.

There are lots of paranoids out there, it also depends on your own scale of paranoia. Everything is relative when talking about security.

On most cases, and unless your enemy has technology borrowed from the NSA or the NASA, you are secure by just simply overwriting the files, which makes any software based recovery impossible.

Some people think that journal file systems are less secure when erasing. The truth is that it depends. Imagine the following scenario: you are deleting lots of files, and an electrical outage interrupts it, the truth is that a journal file system will replay the operations that are not completed, but a non-journal one will not, leaving the data exposed. Which is more secure now? :P

As you see, it's all relative. While journal file systems are prone to leave metadata around (and it's not trivial to remove it), that's nothing compared to what a non-journal one can do if something fails, since then, potentially, all the file contents will be around, which is far worse. Not to talk about data integrity, which is easily conserved in a journal file system. Note that this affirmation I made might not be accurate, or even be completely wrong depending on the type of journaling you selected. Ext3 is a very versatile and configurable system and can use journals on many different ways.

There's no best way here. Note that both the journal and the redundant rewrites takes lots of cpu cycles. But without them you risk data integrity for the former, and privacy on the later. Encryption hurts greatly the performance, but on the contrary, greatly protects against both, filesystem and low level based unauthorized access.

As you see, it's always a matter of trades: you can't get everything.

This is from my bookmarks, I hope it's of any use to you:

http://www.filesystems.org/docs/secdel/secdel.html


If you really want to convert the filesystem to ext2 I suggest you to:

1.- remove the journal using tune2fs
2.- mount the filesystem as ext2
3.- you can optionally rewrite the empty space by making a big file with dd if=/dev/ramdom of=/bigfile, afterwards you can remove it. This step is not strictly needed. It's just to delete any traces of previous files if you wish.

I am not an expert in security by any means, so don't take any word in this post as an absolute truth either.