The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/11/pgupgrade.html Description:
pg_upgrade seems to assume that the datadir and the configdir are the same but on Debian/Ubuntu they are not the same by default (installing from the postgres repository). The current documentation: -d configdir --old-datadir=configdir the old database cluster configuration directory; environment variable PGDATAOLD -D configdir --new-datadir=configdir the new database cluster configuration directory; environment variable PGDATANEW In order for this to work on Debian/Ubuntu you need to also pass some options with the actual configuration directory. For example: -o 'config_file=/etc/postgresql/9.6/main/postgresql.conf' -O 'config_file=/etc/postgresql/10/main/postgresql.conf' I think the documentation could use some clarification on this point.