rsync - Jan 2004 - File rename detection?

Hello!

As I was found rsync do not detect file renaming. If I just copy my
backup.0.tgz (many Mbytes in size having it's md5) to backup.1.tgz
(which will be equial in size and md5) it will be the same file
in fact...

Rsync will delete old file (backup.0.tgz) on the receiving side and
download new one (backup.1.tgz). I do not think there are any
difficulties to detect this situation and follow the natural way:
just rename the file on the receiving side.

Am I right?

--
Dmitry

On Wed, Jan 28, 2004 at 09:06:52PM +0300, ??????? ????????
wrote:
> Hello!
> 
> As I was found rsync do not detect file renaming. If I just copy my
> backup.0.tgz (many Mbytes in size having it's md5) to backup.1.tgz
> (which will be equial in size and md5) it will be the same file
> in fact...
> 
> Rsync will delete old file (backup.0.tgz) on the receiving side and
> download new one (backup.1.tgz). I do not think there are any
> difficulties to detect this situation and follow the natural way:
> just rename the file on the receiving side.
> 
> Am I right?
Reliably detecting renamed files in a manner that rsync can
act on it is very difficult.

-- 
________________________________________________________________
	J.W. Schultz            Pegasystems Technologies
	email address:		jw@pegasys.ws

		Remember Cernan and Schmitt

I have a feeling that the problem of file-renaming does not have a good 
solution in general, but it may be possible for people to come up with a 
rule-based or pattern-based algorithm that works for their particular 
environment (e.g. I use emacs so I'd want rsync to check file.c~ when 
trying to match file.c).

Anyway, I thought I'd mention that there is still a patch in the rsync 
source tree that was submitted a long time ago to attempt a "fuzzy" 
match on file names (patches/rusty-fuzzy.diff). It doesn't patch 
correctly on the current sources, BTW.


-- Alberto


On Wed, Jan 28, 2004 at 05:12:04PM -0800, jw schultz wrote:

 >> On Thu, Jan 29, 2004 at 11:42:12AM +1100, Donovan Baarda wrote:
 >
 >>> > On Thu, 2004-01-29 at 06:27, jw schultz wrote:
 >>
 >>>> > > On Wed, Jan 28, 2004 at 09:06:52PM +0300, ???????
???????? wrote:
 >>>
 >>>>> > > > Hello!
 >>>>> > > >
 >>>>> > > > As I was found rsync do not detect file
renaming. If I just
copy my
 >>>>> > > > backup.0.tgz (many Mbytes in size having
it's md5) to
backup.1.tgz
 >>>>> > > > (which will be equial in size and md5) it
will be the same file
 >>>>> > > > in fact...
 >>>>> > > >
 >>>>> > > > Rsync will delete old file (backup.0.tgz)
on the receiving
side and
 >>>>> > > > download new one (backup.1.tgz). I do not
think there are any
 >>>>> > > > difficulties to detect this situation and
follow the
natural way:
 >>>>> > > > just rename the file on the receiving side.
 >>>>> > > >
 >
 >>
 >>
 >> In most cases it is reasonable to adjust file naming schemes
 >> to use less ephemeral names thereby avoiding the problem
 >> altogether.



-- 

**************************************************************************
Alberto Accomazzi, NASA Astrophysics Data System    http://ads.harvard.edu
Harvard-Smithsonian Center for Astrophysics     http://cfa-www.harvard.edu
60 Garden St, MS 31, Cambridge, MA 02138, USA   aaccomazzi@cfa.harvard.edu
**************************************************************************