AiiDA needs a database backend to store the nodes, node attributes and other information, allowing the end user to perform very fast queries of the results. Currently, only postgresql is allowed as a database backend.

Setup instructions

In order for AiiDA to be able to use postgres it needs to be installed first. On Ubuntu and other Debian derivative distributions this can be accomplished with:

$ sudo apt-get install postgresql postgresql-server-dev-all postgresql-client

For Mac OS X, binary packages can be downloaded from the official website of postgresql or you can use brew:

$ brew install postgresql
$ pg_ctl -D /usr/local/var/postgres start

To manually create a database for AiiDA that will later be used in the configuration with verdi setup, you should follow these instructions. First you will need to run the program psql to interact with postgres and you have to do so as the postgres user that was created upon installing the software. To assume the role of postgres run as root:

$ su - postgres

and launch the postgres program:

$ psql

Create a new database user account for AiiDA by running:

CREATE USER aiida WITH PASSWORD '<password>';

replacing <password> with a password of your choice. Make sure to remember it, as you will need it again when you configure AiiDA to use this database through verdi setup. If you want to change the password you just created use the command:

ALTER USER aiida PASSWORD '<password>';

Next we create the database itself:


and grant all privileges on this DB to the previously-created aiida user:


You have now created a database for AiiDA and you can close the postgres shell by typing \q. To test if the database was created successfully, you can run the following command as a regular user in a bash terminal:

$ psql -h localhost -d aiidadb -U aiida -W

and type the password you inserted before, when prompted. If everything worked well, you should get no error and see the prompt of the psql shell.

If you uses the same names used in the example commands above, during the verdi setup phase you want to use the following parameters to use the database you just created:

Database engine: postgresql_psycopg2
PostgreSQL host: localhost
PostgreSQL port: 5432
AiiDA Database name: aiidadb
AiiDA Database user: aiida
AiiDA Database password: <password>


Do not forget to backup your database (instructions here).


If you want to move the physical location of the data files on your hard drive AFTER it has been created and filled, look at the instructions here.


Due to the presence of a bug, PostgreSQL could refuse to restart after a crash, or after a restore from binary backup. The workaround given below is adapted from here. The error message would be something like:

* Starting PostgreSQL 9.1 database server
* The PostgreSQL server failed to start. Please check the log output:
2015-05-26 03:27:20 UTC [331-1] LOG:  database system was interrupted; last known up at 2015-05-21 19:56:58 UTC
2015-05-26 03:27:20 UTC [331-2] FATAL:  could not open file "/etc/ssl/certs/ssl-cert-snakeoil.pem": Permission denied
2015-05-26 03:27:20 UTC [330-1] LOG:  startup process (PID 331) exited with exit code 1
2015-05-26 03:27:20 UTC [330-2] LOG:  aborting startup due to startup process failure

If this happens you should change the permissions on any symlinked files to being writable by the Postgres user. For example, on Ubuntu, with PostgreSQL 9.1, the following should work (WARNING: Make sure these configuration files are symbolic links before executing these commands! If someone has customized the server.crt or server.key file, you can erase them by following these steps. It’s a good idea to make a backup of the server.crt and server.key files before removing them):

(as root)
# go to PGDATA directory
cd /var/lib/postgresql/9.1/main
ls -l server.crt server.key
# confirm both of those files are symbolic links
# to files in /etc/ssl before going further
# remove symlinks to SSL certs
rm server.crt
rm server.key
# copy the SSL certs to the local directory
cp /etc/ssl/certs/ssl-cert-snakeoil.pem server.crt
cp /etc/ssl/private/ssl-cert-snakeoil.key server.key
# set permissions on ssl certs
# and postgres ownership on everything else
# just in case
chown postgres *
chmod 640 server.crt server.key

service postgresql start