title: How do I get write access to EFS from Lambda?
body: <p>I've created a lambda function.
  I created a Elastic File System (EFS) and access points using all the default settings.
  I attached the EFS to the lambda function, again just using the defaults.</p>
  <p>But! There is no write access to EFS.</p>
  <p>What did I miss?</p>
  <p>Hope some kind person knows :)</p>
  <p><strong>Notes....</strong></p>
  <p><em>The current answer doesn't seem to work. I've also been onto AWS support for over a week. They seem to think the EFS is not mounting.</em></p>
  <p>EFS is mounted to lambda at = /mnt/fs</p>
  <p>EFS Access point - Root Directory Path = / (A suggestion of changing this to /fs causes an internal server error, AWS support suggested /mnt/fs which also causes an internal service error).</p>
  <p>AmazonElasticFileSystemClientFullAccess and AWSLambdaVPCAccessExecutionRole added to execution role.</p>
  <p><strong>Test Node js example:</strong></p>
  <pre><code>exports.handler = function(event, ctx, callback) {
      const fs = require(&quot;fs&quot;);
      fs.mkdir('/mnt/fs/newfolder', { recursive: true }, (err) =&gt; {
          callback(null, {
              statusCode: 200,
              &quot;content-type&quot;: &quot;text/html&quot;,
              body: (err || &quot;ok&quot;).toString()
          })
      });
  };
  </code></pre>