Thanks, most of these came out restriction, we cant afford to throw money on horizontal scaling (adding more server,load server etc). So we kind of forced to try out new things to keep cost affordable. There are many thing left out on above doc: IIRC, we started with openvz and even today our security relies on SELinux, how we remapped user account creation with pre-existing templates for ext4 quota, we moved to xfs because of flexibility. Mysqldb quota/limits, fork bombs by college/school students bringing out docker environment. Old school internet is right term.