partial-dir not being used?!

[Carlos Carvalho]

Matt McCutchen (matt at mattmccutchen.net) wrote on 15 July 2009 18:50:
 >On Wed, 2009-07-15 at 17:01 -0300, Carlos Carvalho wrote:
 >> Here's a running instance caught by ps (lines broken for readibility):
 >> 
 >> rsync --perms --times --timeout=3600 --stats --no-motd -hh --force
 >> --hard-links -ii --links --partial-dir=.~tmp~ --recursive --exclude
 >> <some excludes> --out-format=<format> --delete-during
 >> --max-delete=75000 --ignore-errors source dest
 >> 
 >> During download files are being created at
 >> path/.filename.random-string instead of path/.~tmp~/filename. How can
 >> this be? Version is 3.0.6 on linux.
 >
 >That's a temporary file, which goes in the --temp-dir.  Rsync will move
 >the file to the --partial-dir if the transfer is interrupted.

What's the purpose of --partial-dir then? I thought it was leaving the
partial transfer as path/partial/filename instead of
path/.filename.random. That's what it tried to do but this isn't fine
if it needs another move. If rsync is killed with STOP or the machine
crashes this partial will be lost? That doesn't look very useful.

How can we make rsync put the partial in path/partial/filename during
the transfer?