On Sunday, July 6, 2025, PG Bug reporting form <
noreply@postgresql.org> wrote:
The following bug has been logged on the website:
Bug reference: 18979
Logged by: Jorge Solorzano
Email address: jorsol@gmail.com
PostgreSQL version: 17.5
Operating system: Linux
Description:
The upgrade fails with the following error:
command: "/usr/pgsql-17/bin/pg_ctl" -w -l
"/var/lib/pgsql/17/data/pg_upgrade_output.d/20250706T152559.441/log/pg_upgrade_server.log"
-D "/var/lib/pgsql/17/data" -o "-p 50432 -b -c synchronous_commit=off -c
fsync=off -c full_page_writes=off -c max_slot_wal_keep_size=-1 -c
listen_addresses='' -c unix_socket_permissions=0700 -c
unix_socket_directories='/var/lib/pgsql'" start >>
"/var/lib/pgsql/17/data/pg_upgrade_output.d/20250706T152559.441/log/pg_upgrade_server.log"
2>&1
waiting for server to start....2025-07-06 13:25:59.929 GMT [9439] LOG:
invalid value for parameter "max_slot_wal_keep_size": 500
2025-07-06 13:25:59.929 GMT [9439] DETAIL: "max_slot_wal_keep_size" must be
set to -1 during binary upgrade mode.
2025-07-06 15:25:59.930 CEST [9439] FATAL: configuration file
"/var/lib/pgsql/17/data/postgresql.conf" contains errors
stopped waiting
pg_ctl: could not start server
Additional Context:
While pg_upgrade does pass other required parameters like -c
max_slot_wal_keep_size=-1 on the command line when starting the new cluster
in upgrade mode, the value in postgresql.conf appears to override this,
leading to startup failure.
It doesn’t override it but both the value in the conf and the one on the startup command are evaluated and the one in the conf causes the failure before the startup command version can restore the system to a valid state. I.e., validation is not deferred.
It would be helpful if pg_upgrade temporarily overrides the setting
correctly, regardless of the static config.
The existing behavior by pg_upgrade makes sense but it pointless given the existing implementation of setting handling. It seems doable to remove the check from the setting area and place it elsewhere.
David J.
