Synch group with different gid

[Fabian Cenedese]

At 08:30 11.05.2016, Fabian Cenedese wrote:
>Content-Transfer-Encoding: 7bit
>
>Hello
>
>I have a problem while synching between two NAS boxes with Linux.
>First NAS: group staff=50 (3.0.3pre1)
>Second NAS: groups ftp=50, staff=500 (rsync 3.1.1)
>
>I synched with -rptgo, without --numeric-ids. The expected result
>was that the items on the second group would be staff as well
>even with a different gid. However it looks like the 50 was taken
>literally and now all staff items are ftp items.
>
>1. How could this happen? Is this expected, did I do something wrong?
>2. How can I now synch the ownership correctly?
>
>I tried with -a, with --super, but so far the ownership is not synched.

I can now synch the group by using --groupmap=50:staff. Just doing
--groupmap=ftp:staff or leaving it off doesn't change anything on the
receiving side. However then I don't understand the default behaviour.
Shouldn't that already have happened in the normal use case without
--numeric-ids and --groupmap?

Thanks

bye  Fabi