postmaster.opts is a file in the data directory written after startup which contains the options used to start the postmaster process. The contents of
postmaster.opts are used to ensure the postmaster process can be restarted with the same options with which it was originally started.
postmaster.opts was added in PostgreSQL 7.0.
postmaster.opts following a startup with custom options:
$ pg_ctl -D /tmp/opttest -l /tmp/opttest.log -o '-p5434' start $ cat /tmp/opttest/postmaster.opts /usr/local/bin/postgres "-D" "/tmp/opttest" "-p5434"
postmaster.opts must be present for a restart to succeed:
$ rm /tmp/opttest/postmaster.opts $ pg_ctl -D /tmp/opttest restart waiting for server to shut down.... done server stopped pg_ctl: could not read file "/tmp/opttest/postmaster.opts"