title: MySQL 8.0 No data dictionary version number found
body: <p>I have updated MySQL 8.0.3 to 8.0.4 on my test server. However, it does not start the service.</p>
  
  <p>Attached information of the LOG:</p>
  
  <pre><code>2018-01-24T04:32:26.996977Z 0 [System] [MY-010116] /usr/sbin/mysqld (mysqld 8.0.4-rc-log) starting as process 12406 ...
  2018-01-24T04:32:27.444234Z 1 [ERROR] [MY-011096] No data dictionary version number found.
  2018-01-24T04:32:27.444725Z 0 [ERROR] [MY-010020] Data Dictionary initialization failed.
  2018-01-24T04:32:27.444802Z 0 [ERROR] [MY-010119] Aborting
  2018-01-24T04:32:28.806928Z 0 [System] [MY-010910] /usr/sbin/mysqld: Shutdown complete.
  </code></pre>
  
  <p>I also try to run mysqld_safe and it throws me the following:</p>
  
  <pre><code>2018-01-24T04: 25: 33.852181Z mysqld_safe Logging to '/var/log/mysql/error.log'.
  2018-01-24T04: 25: 33.857404Z mysqld_safe Directory '/var/run/mysqld' for UNIX socket file do not exists.
  </code></pre>
  
  <p>The directory does not exist so I proceed to create it again:</p>
  
  <pre><code>sudo mkdir -p /var/run/mysqld
  sudo chown mysql: mysql /var/run/mysqld
  sudo mysqld_safe
  </code></pre>
  
  <p>He throws the following at the console:</p>
  
  <p>2018-01-24T04: 27: 29.816902Z mysqld_safe Logging to '/var/log/mysql/error.log'.
  2018-01-24T04: 27: 29.870025Z mysqld_safe Starting mysqld daemon with databases from / var / lib / mysql
  nohup / usr / sbin / mysqld --basedir = / usr --datadir = / var / lib / mysql --plugin-dir = / usr / lib / mysql / plugin --user = mysql --log-error = / var /log/mysql/error.log --pid-file = / var / run / mysqld / mysqld.pid --socket = / var / run / mysqld / mysqld.sock --port = 3309 
  
  <p>I proceed again to start the service and throw me:</p>
  
  <pre><code>Job for mysql.service failed because of the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.
  </code></pre>
  
  <p>I search the log and the following comes up:</p>
  
  <pre><code>2018-01-24T04: 30: 11.601843Z 0 [System] [MY-010116] /usr/sbin/mysqld (mysqld 8.0.4-rc-log) starting as process 9140 ...
  2018-01-24T04: 30: 12.001705Z 1 [ERROR] [MY-011096] No data dictionary version number found.
  2018-01-24T04: 30: 12.002121Z 0 [ERROR] [MY-010020] Data Dictionary initialization failed.
  2018-01-24T04: 30: 12.002232Z 0 [ERROR] [MY-010119] Aborting
  </code></pre>
  
  <p>What could I do to start the service? I have reviewed the /var/lib/ mysql directory and there are the databases.</p>