Objective: Backup standby database (synchronous streaming replication) using LVM snapshot.
When running pg_start_backup:
postgres=# SELECT pg_start_backup('label');
ERROR: recovery is in progress
HINT: WAL control functions cannot be executed during recovery.
Is it possible to copy
tablespace_map from the primary database's cluster directory into the standby database's cluster directory in order to perform the LVN snapshot backup of the standby cluster directory?