title: lower_case_table_names=1 on Ubuntu 18.04 doesn't let mysql to start
body: <p>I have installed mysql community server 8.013 on ubuntu 18.04 and I have the following issue.
  I want to set lower_case_table_names=1 in order to have case insensitive table names in my db.
  I edited /etc/mysql/mysql.conf.d/mysqld.cnf and added the following line under [mysqld]</p>
  
  <pre><code>lower_case_table_names=1
  </code></pre>
  
  <p>mysqld.cnf now is as follows</p>
  
  <pre><code>[mysqld]
  pid-file        = /var/run/mysqld/mysqld.pid
  socket          = /var/run/mysqld/mysqld.sock
  datadir         = /var/lib/mysql
  log-error       = /var/log/mysql/error.log
  lower_case_table_names=1
  </code></pre>
  
  <p>I stopped the mysql server using</p>
  
  <pre><code>sudo service mysql stop
  </code></pre>
  
  <p>Then I tried to start it again using</p>
  
  <pre><code>sudo service mysql start
  </code></pre>
  
  <p>but I get the following error</p>
  
  <pre><code>Job for mysql.service failed because the control process exited with error code.
  See "systemctl status mysql.service" and "journalctl -xe" for details.
  </code></pre>
  
  <p>I tried </p>
  
  <pre><code>systemctl status mysql.service
  </code></pre>
  
  <p>and I got the following info </p>
  
  <pre><code>christoph@christoph-Latitude-E6530:/etc/init.d$ systemctl status mysql.service
  ● mysql.service - MySQL Community Server
     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Thu 2018-11-01 16:38:14 EET; 24s ago
       Docs: man:mysqld(8)
             http://dev.mysql.com/doc/refman/en/using-systemd.html
    Process: 6681 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)
    Process: 6642 ExecStartPre=/usr/share/mysql-8.0/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
   Main PID: 6681 (code=exited, status=1/FAILURE)
     Status: "SERVER_BOOTING"
      Error: 2 (No such file or directory)
  
  Νοε 01 16:38:12 christoph-Latitude-E6530 systemd[1]: Starting MySQL Community Server...
  Νοε 01 16:38:14 christoph-Latitude-E6530 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
  Νοε 01 16:38:14 christoph-Latitude-E6530 systemd[1]: mysql.service: Failed with result 'exit-code'.
  Νοε 01 16:38:14 christoph-Latitude-E6530 systemd[1]: Failed to start MySQL Community Server.
  </code></pre>
  
  <p>using journalctl -xe I got the following info</p>
  
  <pre><code>-- The result is RESULT.
  Νοε 01 17:32:00 christoph-Latitude-E6530 sudo[2526]: pam_unix(sudo:session): session closed for user root
  Νοε 01 17:32:04 christoph-Latitude-E6530 wpa_supplicant[743]: wlp3s0: WPA: Group rekeying completed with 4c:5e:0c:7a:95:cf [GTK=CCMP]
  Νοε 01 17:32:08 christoph-Latitude-E6530 gnome-shell[1565]: Some code accessed the property 'discreteGpuAvailable' on the module 'appDisplay'. That property w
  Νοε 01 17:32:08 christoph-Latitude-E6530 gnome-shell[1565]: Some code accessed the property 'WindowPreviewMenuItem' on the module 'windowPreview'. That proper
  lines 1349-1371/1371 (END)
  Νοε 01 17:31:58 christoph-Latitude-E6530 systemd[1]: Starting MySQL Community Server...
  -- Subject: Unit mysql.service has begun start-up
  -- Defined-By: systemd
  -- Support: http://www.ubuntu.com/support
  -- 
  -- Unit mysql.service has begun starting up.
  Νοε 01 17:31:58 christoph-Latitude-E6530 audit[2593]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/usr/sbin/mysqld" pid=2593 comm=
  Νοε 01 17:31:58 christoph-Latitude-E6530 kernel: kauditd_printk_skb: 28 callbacks suppressed
  Νοε 01 17:31:58 christoph-Latitude-E6530 kernel: audit: type=1400 audit(1541086318.959:39): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name
  Νοε 01 17:32:00 christoph-Latitude-E6530 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
  Νοε 01 17:32:00 christoph-Latitude-E6530 systemd[1]: mysql.service: Failed with result 'exit-code'.
  Νοε 01 17:32:00 christoph-Latitude-E6530 systemd[1]: Failed to start MySQL Community Server.
  -- Subject: Unit mysql.service has failed
  -- Defined-By: systemd
  -- Support: http://www.ubuntu.com/support
  -- 
  -- Unit mysql.service has failed.
  </code></pre>
  
  <p>I also tried to start the server using </p>
  
  <pre><code>sudo service mysql start --initialize lower_case_table_names=1
  </code></pre>
  
  <p>as described here
  <a href="https://stackoverflow.com/questions/51803216/lower-case-table-names-settings-in-mysql-8-0-12/51804009?noredirect=1#comment93087502_51804009">lower_case_table_names Settings in MySQL 8.0.12</a>
  but I still get the same error and mysql doesn't start at all</p>
  
  <p>If I run the following </p>
  
  <pre><code>sudo vi /var/log/mysql/error.log
  </code></pre>
  
  <p>I get the following cause of the error</p>
  
  <pre><code>Different lower_case_table_names settings for server ('1') and data dictionary ('0').
  Data Dictionary initialization failed.
  </code></pre>
  
  <p>Any ideas why this is happening and how to fix it?</p>