The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/11/runtime-config-resource.html
Description:
The server has an undocumented maximum value of 10 for
bgwriter_lru_multiplier, and will fail to start if it's set higher than
this:
LOG: 20 is outside the valid range for parameter "bgwriter_lru_multiplier"
(0 .. 10)
FATAL: configuration file "/.../pgdata/postgresql.conf" contains errors