<notextile><pre>~$ <span class="userinput">sudo service rh-postgresql94-postgresql start</span></pre></notextile>
# "Set up Arvados credentials and databases":#rails_setup for the services that will use this PostgreSQL install.
+h2(#centos7). Install PostgreSQL on CentOS 7
+
+# Install PostgreSQL:
+ <notextile><pre>~$ <span class="userinput">sudo yum install postgresql-server</span></pre></notextile>
+# Initialize the database:
+ <notextile><pre>~$ <span class="userinput">sudo postgresql-setup initdb</span></pre></notextile>
+# Configure the database to accept password connections:
+ <notextile><pre><code>~$ <span class="userinput">sudo sed -ri -e 's/^(host +all +all +(127\.0\.0\.1\/32|::1\/128) +)ident$/\1md5/' /var/lib/pgsql/data/pg_hba.conf</span></code></pre></notextile>
+# Configure the database to launch at boot:
+ <notextile><pre>~$ <span class="userinput">sudo systemctl enable postgresql</span></pre></notextile>
+# Start the database:
+ <notextile><pre>~$ <span class="userinput">sudo systemctl start postgresql</span></pre></notextile>
+# "Set up Arvados credentials and databases":#rails_setup for the services that will use this PostgreSQL install.
+
h2(#debian). Install PostgreSQL on Debian or Ubuntu
# Install PostgreSQL: