pg_dropcluster - completely delete a PostgreSQL cluster
pg_dropcluster [--stop] cluster-version cluster-name
This program removes all files that belong to a given PostgreSQL cluster; that includes the data, wal, and tablespace directories, the log file, and all configuration files that were created by pg_createcluster(1). If the configuration directory (/etc/postgresql/version/cluster) is empty after this, it is removed as well. An empty socket directory other than /var/run/postgresql or /tmp is also removed.
Usually a cluster which still has a running server attached will not be deleted. To override this, the --stop option forces a server shutdown before the files are removed.
pg_createcluster(1), pg_ctlcluster(1)
Martin Pitt <mpitt@debian.org>