symlinks that become directories question

[Matt McCutchen]

On Mon, 2007-10-29 at 13:15 -0400, rob at mangiafico.net wrote: 
> If I have a backup script that does the following:
> (latest 2.6.9 rsync)
> 
> rsync --archive --hard-links --force --ignore-errors --numeric-ids 
> --keep-dirlinks --delete / /backup
> 
> I've found that if there is a symlink in place that gets backed up (which 
> goes fine), i.e.:
> homelink -> /home/
> 
> and then that symlink gets changed into an actual directory, i.e.:
> rm homelink
> mkdir homelink

I assume this directory is empty? 

> rsync will actually delete everything in the directory that the symlink 
> pointed to (in the above case it deletes /home).

Rsync's behavior, however surprising, is correct.  Since you passed
--keep-dirlinks, rsync is mapping the source's "homelink" directory to
the target directory of the destination's "homelink" symlink,
i.e., /home.  (Without --keep-dirlinks, rsync would first replace the
destination's "homelink" with an actual directory.)  Since you passed
--delete, rsync deletes any and all files from /home that lack
counterparts in the source's "homelink".

> Is the workaround to use --delete-after to avoid this behavior, or is my 
> logic flawed in using rsync with the command above to produce a mirror 
> copy of an entire server to a backup drive?

--delete-after gives the same behavior.  To stop rsync from following
the destination's symlink to /home, you will have to remove
--keep-dirlinks.  Unfortunately, if there are other dirlinks that you
*do* need to keep, you will have to do something more complicated.

Matt