title: Restore old data to new version of Postgres
body: <p>I have postgres installed on a server (version 9.3).
  I plan to change server and update Postgres to new version.
  In my new server I have Postgres v.12</p>
  <p>I have copied the raw data files from old server to new server. Data is pasted in folder /var/lib/postgres/12/main/</p>
  <p>I am not able to see databases in new server with command /l</p>
  <p>What steps should I take to restore these databases to newer versions from raw data file folder?</p>