I would like to create a mirror, so i copied some stuff via a high-speed connection and transfered it home. I typed the command "rsync -rtlv ......." in order to fill in the "blanks"- the missing files ( i hadn't downloaded anything i needed) using my 384 adsl. However, i think that at the present time rsync isn't filling the "blanks" only, but is also replacing stuff.

How can i find out if this is true?
How can i stop it this from happening? - I thought that the main characteristic of rsync was, that it also files that have changed, deletes old ones, download new ones, after comparing some file lists.
Thanks

It depends on the options you use. For mirroring, I usually use:

rsync --rsh="ssh" -av --partial --delete-after --progress source destination

The 'man rsync' command will provide full documentation on rsync and its options.

Another question:
I rsync to a folder containing only rpms:
---------------------
FreeWnn-1.10pl020-6.fc4.i386.rpm
FreeWnn-devel-1.10pl020-6.fc4.i386.rpm
FreeWnn-libs-1.10pl020-6.fc4.i386.rpm
GiNaC-1.3.1-6.fc4.i386.rpm
...rpms
---------------------

However in my local folder the following 3 folders are added:
---------------------
debug
repodata
headers
FreeWnn-1.10pl020-6.fc4.i386.rpm
FreeWnn-devel-1.10pl020-6.fc4.i386.rpm
FreeWnn-libs-1.10pl020-6.fc4.i386.rpm
GiNaC-1.3.1-6.fc4.i386.rpm
...rpms
---------------------
I don't think that something like this has happened in other occasions. Is this something, that the admin has programed? Is this the default behavior of the rsync?
What caused it anyway?
Thanks

The directories existed at some point, so rsync copied them. Unless you use one of the delete options (like "--delete-after" in my example), files and directories will accumulate - they will never be deleted, even if they are deleted from the source.