postgresql 9.3: two instances on same port and two different ip adresses don't work i'm setting up multiple instances of postgres 9.3 on the same machine (centos 7). I have 2 virtual ip addresses, one instance is bound to first address and second is bound to second one. Same configuration is working on postgres 8.4 and very old red hat server.

I have configured 2 .service files in /usr/lib/systemd/system and i have done the setup initdb servicename commands.

the problem is: if i starts first service it goes well, but the second says that /tmp/.s.PGSQL.5432.lock file already exists. 

in previuos db and os version i could set two different /var/run path in order to manage two instances,but now i cannot do it beacause i don't find any setting to write lock file where i want.

obviously if i change listening port on second instance all works well beacuse it create another lock file with different name,but i would to mantian same configuration. I don't know if in new version they delete the possibility to have 2 instances on same port and different ips but it seems strange to me.

how can i do?

thanks
You must also set separate unix_socket_directories.