# How to upgrade PostgreSQL on Ubuntu I recently upgraded PostgreSQL from version 16 to 17 on my Hetzner Ubuntu server, hosting the production instance of [Knowii](https://knowii.net). Here are the steps I followed: ## Upgrade steps These steps include the following version numbers: - 16: old version - 17: new version Adapt those as needed for your particular case. - Install the new packages. Since the latest ones may not be available yet on the official Ubuntu repositories, need to add the official PostgreSQL ones - `sudo sh -c 'echo "deb [http://apt.postgresql.org/pub/repos/apt](http://apt.postgresql.org/pub/repos/apt) $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'` - `wget -qO- [https://www.postgresql.org/media/keys/ACCC4CF8.asc](https://www.postgresql.org/media/keys/ACCC4CF8.asc) | sudo tee /etc/apt/trusted.gpg.d/pgdg.asc &>/dev/null` - `sudo apt update` - `sudo apt install postgresql` - At this point both versions of PostgreSQL should be installed - `dpkg --get-selections | grep postgres` - Note that the new version will have created a default cluster called `main` (empty and unused at this point) - Verify the version running before the upgrade - `psql -c 'select version();'` - Stop the PostgreSQL service - `sudo service postgresql stop` - Rename the new version's default cluster name from `main` to `main_pristine` - `sudo pg_renamecluster 17 main main_pristine` - Upgrade the old cluster to the new version - `sudo pg_upgradecluster 16 main` - This will migrate the data, accounts, etc - Stop and delete the old cluster (unused at this point) - `sudo pg_dropcluster 16 main --stop` - At this point there is a v17 `main` cluster and the v17 `main_pristine` cluster that we renamed earlier - Stop and delete the default cluster of v17 - `sudo pg_dropcluster 17 main-pristine stop` - Start the PostgreSQL service - `sudo service postgresql start` - Verify that the version running now is the correct one - `psql -c 'select version();'` - Remove the old version packages - `sudo apt-get remove postgresql-16 postgresql-client-16` ## References - https://gorails.com/guides/upgrading-postgresql-version-on-ubuntu-server - https://askubuntu.com/questions/1456014/how-to-upgrade-postgresql-from-14-to-15-on-ubuntu-22-04