Re: pg_upgrade 13.6 to 15.1?

pf(at)pfortin(dot)com writes:
> Trying to upgrade from 13.6 to 15.1, pg_upgrade complains with:
> [postgres(at)pf ~]$ /usr/bin/pg_upgrade -b /usr/local/pgsql/bin -B /usr/bin \
> -d /mnt/db/var/lib/pgsql/data -D /mnt/work/var/lib/pgsql/data \
> -s /tmp -U postgres

> This utility can only upgrade to PostgreSQL version 15. <=====<<< ??

This indicates that it thinks the new data directory (-D) is the
wrong version. Perhaps the error message could be clearer about that.

> Due to the database size, I have the working copy on a 4TB NVMe SSD
> mounted at /mnt/work/var/lib/{pgadmin,pgsql} and an identical copy on an
> 18TB platter at /mnt/db/var/lib/{pgadmin,pgsql}. Both copies are
> currently at 13.6.

I think you misunderstand how this is supposed to work. The -D
argument should point at an *empty* data directory that has been
freshly initialized with the new version's initdb. pg_upgrade then
transfers data into that from the old database (-d argument).

regards, tom lane