> the goal is, that the FTP server is a Dropbox for Alice, so she can > upload files and folders and is not able to see the uploaded files > (drwx-wx--- for the main older). > > Bob should be able to rename the files and folders by ftp. (and of > course be able to download them.) > > If this is not possible with the standad permissions, I'm fine, in the > past Users did not try to upload folders and others did not rename > ...Than we look for an other workflow. There is a much more fine-grained ACL system in Linux which sits on top of the standard file permissions. Have a look at, for instance, https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/ch-acls.html or 'man acl' With this you will be able to give specific users different access permissions on the files created. As someone else said, ProFTPD also has a finer-grained permission system - you can change access according to which user is logged in via FTP and you can change which commands they have access to. In other words you allow Alice access to a subset of commands which allow her to upload files and create directories but not rename them. P.