My database has stopped deleting WAL files and
pg_xlog grows to eventually take all my disk space. I have to use
pg_archivecleanup to delete them manually.
I'm almost certain it's to do with my tinkering with replication, but I thought I removed it, and the only remnant of that I can see is the replication slot, but when I try to remove it:
pg_drop_replication_slot('barman') causes  ERROR: replication slots can only be used if wal_level > = archive. Which I find strange because I'm trying to remove it, not use it.
$ barman list-server shows nothing
SHOW wal_level minimal
SHOW archive_command (disabled)
SELECT * FROM pg_replication_slots barman,,physical,,,false,,,,23/DF000000
SHOW server_version 9.5.14
My postgresql.conf is absent of all WAL settings except
max_replication_slots = 1, which I tried to set to
0, but the database will not start if I do.
How can I remove my replication slot, or otherwise troubleshoot postgres not deleting its WAL files?