Run multiple PostgreSQL instances on one machine
October 26, 2019
I’m on Ubuntu 18.04 having PostgreSQL 10.10 installed. For testing I had to run PostgreSQL 9.5 along with 10.10.
If you don’t know how to install version 9 on Ubuntu 18.04 check this doc on postgres site.
To install version 9.5 just run:
sudo apt install postgresql-9.5
That’s it. You should not face any other issues.
I’ve been always starting postgres instance with
sudo service postgresql start but now,
when we have two different version we should use:
sudo systemctl start firstname.lastname@example.org
9.5-main at the end is the cluster name. Cluster is something we always have per database version. You can find all the clusters you have on your machine with:
The output looks like this:
Ver Cluster Port Status Owner Data directory Log file 9.5 main 5432 online postgres /var/lib/postgresql/9.5/main /var/log/postgresql/postgresql-9.5-main.log 10 main 5432 down postgres /var/lib/postgresql/10/main /var/log/postgresql/postgresql-10-main.log
You can see that right now I have 9.5 running and 10 down.
To run version 10 again just stop the 9.5 instance and run
sudo systemctl start postgresql@10-main
If you want to run both instances simultaneously then you have to edit
postgresql.conf of your version
(every version’s config file is in its own directory under
/etc/postgresql) and set another port to listen in one of your versions.