Re: WAPBL and recovery

[David Holland <dholland-tech%netbsd.org@localhost>]

On Fri, Aug 22, 2008 at 01:21:11PM +0200, Marcin M. Jessa wrote:
 > > Just roll the journal forward, then proceed.
 > 
 > I am not sure what you mean here. How would one "roll the journal forward" ?

This is what happens normally for crash recovery.

 > Does this mean you can role the journal backward as well to get the deleted 
 > (with rm) data back?

No; it only journals metadata. It is possible that with fsdb or
equivalent you might be able to find the data blocks of a recently
deleted file by inspecting the journal, and thus restore the file by
hand if it hasn't been overwritten. I don't know to what extent fsdb
supports this; probably not very much yet.

In general, Unix filesystems don't have undelete.

-- 
David A. Holland
dholland%netbsd.org@localhost