> echo "SELECT pg_is_in_recovery();" | sudo -u postgres psql
 pg_is_in_recovery 
-------------------
 t
(1 row)

> ls -lha /var/lib/postgresql/16/main/standby.signal
-rw------- 1 postgres postgres 0 May  8 18:39 /var/lib/postgresql/16/main/standby.signal

> sudo pg_ctlcluster 16 main promote

> echo "SELECT pg_is_in_recovery();" | sudo -u postgres psql
 pg_is_in_recovery 
-------------------
 f
(1 row)

> ls -lha /var/lib/postgresql/16/main/standby.signal
ls: cannot access '/var/lib/postgresql/16/main/standby.signal': No such file or directory

> echo "CREATE ROLE repl WITH LOGIN REPLICATION PASSWORD 'AejohTe6';" | sudo -u postgres psql
CREATE ROLE

> echo "ALTER ROLE repl SET synchronous_commit = off;" | sudo -u postgres psql
ALTER ROLE

> echo "SELECT rolname, rolreplication FROM pg_roles WHERE rolreplication = true;" | sudo -u postgres psql
 rolname  | rolreplication 
----------+----------------
 postgres | t
 repl     | t
(2 rows)