First-time installs of a given PostgreSQL major release require the instantiation of the database cluster. A database cluster is a collection of databases that are managed by a single server instance. Rationale: For the purposes of security, PostgreSQL enforces ownership and permissions of the data cluster such that: An initialized data cluster is owned by the UNIX account that created it. The data cluster cannot be accessed by other UNIX user accounts. The data cluster cannot be created or owned by root The PostgreSQL process cannot be invoked by root nor any UNIX user account other than the owner of the data cluster. Incorrectly instantiating the data cluster will result in a failed installation.
Solution
Attempting to instantiate a data cluster to an existing non-empty directory will fail: # whoami root # PGSETUP_INITDB_OPTIONS='-k' /usr/pgsql-13/bin/postgresql-13-setup initdb Data directory is not empty! In the case of a cluster instantiation failure, one must delete/remove the entire data cluster directory and repeat the initdb command: # whoami root # rm -rf ~postgres/13 # PGSETUP_INITDB_OPTIONS='-k' /usr/pgsql-13/bin/postgresql-13-setup initdb Initializing database ... OK