I just did a couple of fresh installs to test some things. First I ran everything as root to exclude any permission issues. As I suspected, the directory structure is not created in dyndir if precreateperms is not set even though the documentation states "If unset, the directories will be created dynamically with umask 022." Maybe it works for something else, but not for Master-Slave. The result was "(No such file or directory)" when Slave tries to POST data to the Master.
Then I unset dyndir so the default datadir would be used, where the directory tree is precreated. That worked fine running as root.On the next fresh install I just unset dyndir with everything running as the intended user and surprise: (Permission denied) when Slave tries to POST data to the Master. After setting dyndir to default and setting precreateperms = 775 everything works fine. I'm sure there's a better way with setuid or setfacl or something, and setting lower chmod, but I can't figure it out right now.
