title: ERROR: [050]: unable to acquire lock on file '/tmp/pgbackrest/demo-archive.lock': Permission denied
body: <p>I have been trying to load data incrementally in postgres on linux(ubuntu) from the source (<a href="https://access.crunchydata.com/documentation/pgbackrest/2.00/pdf/backrest.pdf" rel="nofollow noreferrer">https://access.crunchydata.com/documentation/pgbackrest/2.00/pdf/backrest.pdf</a>) while I am trying to create a stanza I am getting the following error.</p>
  
  <p>As I am new to the Linux platform it has been taken more then 2 days and I couldn't solve it!</p>
  
  <pre class="lang-none prettyprint-override"><code>sudo -u postgres pgbackrest --stanza=demo --log-level-console=info stanza-create
  2019-10-03 16:16:22.730 P00   INFO: stanza-create command begin 2.16: --log-level-console=info --pg1-path=/var/lib/postgresql/11/demo --repo1-path=/var/lib/pgbackrest --stanza=demo
  
  ERROR: [050]: unable to acquire lock on file '/tmp/pgbackrest/demo-archive.lock': Permission denied
         HINT: does the user running pgBackRest have permissions on the '/tmp/pgbackrest/demo-archive.lock' file?
  2019-10-03 16:16:22.730 P00   INFO: stanza-create command end: aborted with exception [050]
  
  ERROR: [050]: unable to acquire lock on file '/tmp/pgbackrest/demo-archive.lock': Permission denied
         HINT: does the user running pgBackRest have permissions on the '/tmp/pgbackrest/demo-archive.lock' file?
  2019-10-03 16:16:22.730 P00   INFO: stanza-create command end: aborted with exception [050]
  </code></pre>
  
  <p>What is the reason why this is showing and how to solve it?</p>