title: postgresql doesn't start with Linux
body: <p>I'm facing a problem with postgresql, when I try to execute queries with psql I'm getting this kind of error:</p>
  
  <p><strong>psql: could not connect to server: No such file or directory
      Is the server running locally and accepting
      connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?</strong></p>
  
  <p>the solution I have found on the web is to change access rights for this file:</p>
  
  <p><strong>sudo chmod 777 /var/run/postgresql</strong> and to restart postgresql by this command line <strong>pg_ctl -D /home/mycomputer/var/postgres/ -l logfile restart</strong></p>
  
  <p>After I log as postgres user <strong>sudo su postgres</strong> But for now I'm getting this error message:
  <strong>psql: FATAL:  role "postgres" does not exist</strong></p>
  
  <p>I have searched on the web and didn't find the good way to solve this.</p>
  
  <p>Could someone help me on this please. thank you in advance</p>