Martín Fernández wrote: > After reading the pg_upgrade documentation multiple times, it seems that after running pg_upgrade on the primary instance, we can't start it until we run rsync from the primary to the standby. I'm understanding this from the following section in the pg_upgrade manual page. > > You will not be running pg_upgrade on the standby servers, but rather rsync on the > primary. Do not start any servers yet. Immediately following, you can read: If you did not use link mode, do not have or do not want to use rsync, or want an easier solution, skip the instructions in this section and simply recreate the standby servers once pg_upgrade completes and the new primary is running. So this is not compulsory, it's just an efficient method to quickly get the standby server updated. There is nothing wrong with rebuilding the standby later. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com