Upgrading PostgreSQL 12 to version 14

Shut down MAAS before starting this upgrade

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Create a data backup

Optional but strongly advised: backup all existing data.

sudo -u postgres pg_dumpall > backup.sql

Perform the service upgrade

1. Update and install packages

   bash sudo apt-get update sudo apt-get install postgresql-14 postgresql-server-dev-14

2. Halt the old server

   bash sudo systemctl stop postgresql.service

3. Migrate configuration files

   bash sudo -u postgres /usr/lib/postgresql/14/bin/pg_upgrade \ --old-datadir=/var/lib/postgresql/12/main \ --new-datadir=/var/lib/postgresql/14/main \ --old-bindir=/usr/lib/postgresql/12/bin \ --new-bindir=/usr/lib/postgresql/14/bin \ --old-options '-c config_file=/etc/postgresql/12/main/postgresql.conf' \ --new-options '-c config_file=/etc/postgresql/14/main/postgresql.conf'

4. Reconfigure server ports

   bash sudo vim /etc/postgresql/14/main/postgresql.conf # Set port to 5432 sudo vim /etc/postgresql/12/main/postgresql.conf # Set port to 5433

5. Activate new server and verify version

   bash sudo systemctl start postgresql.service sudo -u postgres psql -c "SELECT version();"

6. Execute new cluster script

   bash sudo -u postgres ./analyze_new_cluster.sh

Reset user passwords

PostgreSQL v14 defaults to scram-sha-256 for password hashing. Redefine all existing passwords.

sudo -u postgres psql
postgres=# \password $USER

Or, modify /etc/postgresql/14/main/pg_hba.conf to switch back to md5. But be cautious, as future versions may not support MD5.

Remove old version

1. Remove old packages

   bash sudo apt-get remove postgresql-12 postgresql-server-dev-12

2. Delete configuration and data

   bash sudo rm -rf /etc/postgresql/12/ sudo -u postgres ./delete_old_cluster.sh