We are building a 6 server WordPress cluster with a load balancer. MariaDB using Galera Cluster so each WordPress instance can use the local MariaDB server on each host. Ubuntu 16.04 NGINX PHP7.0 Redit etc... We would like to have a single location for all /var/www files instead of 6 copies of each. We thought about using the ISPConfig3 Mirroring of servers for configuration but that would prove troublesome for things like Let's Encrypt etc. The real issue is file permissions. Using CIFS allows you to mount a windows share but you are stuck with a single user/group. For instance people might do this for www-data or nobody. For us we like the security that ISPConfig3 uses having a different user/group for each website. So we know that CIFS is out. Would NFS be able to accomplish this? Would we be better off using something like GlusterFS and is it capable of the permissions scheme needed to have many users own their own files? Anyone ever done this and have suggestions on how to proceed? We will be using the MultiSite feature in WordPress but that will be for subsites of certain domains. We originally thought about using MultiSite with Domain Mapping for all sites and have a single WordPress instance but that would be a nightmare. Just the fact that all MySQL tables are in 1 Database was enough to detour that path. So anyone have suggestions?