Retaining undelete data on ext3

[Bodo Thiesen]

Andreas Dilger <adilger at clusterfs.com> wrote:

> On Sep 24, 2006  10:55 -0700, Stephen Samuel wrote:
> > Having just spent a day trying to recover a deleted ext3 file
> > for a friend, I'm wondering about this way of maintining
> > undelete information in ext3, like is done for ext2:
> > 
> > The last step in the deletion process would be to put back
> > the (previously zeroed) block pointers.  Since it gets logged
> > to the journal, I _think_ that this should be safe.  The worst
> > that would happen is that, if the plug gets pulled in the
> > middle of a file delete, the old block pointers would be
> > unavailable --  I don't see this as a killer issue, since
> > editing the filesystem to do an undelete should be considered an
> > emergency operation anyways.
> 
> I've written a couple of times the best way to do this,

Your solution works only for small files.

Big files must managed another way, like how I wrote on Sun, 1 Feb 2004 
07:00:58 +0100 in the thread "Ext3 and undeletion - A way how it could 
work."

But it semms, that the problem is not ideas on how to implement it, but in 
somebody just doing it ...

I don't have the knowledge currently, else I would have done it already.

Regards, Bodo