lower_case_table_names=1 on Ubuntu 18.04 doesn't let mysql to start

Question

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

Answer 1

You need to reinit MySQL data directory. According to https://dev.mysql.com/doc/refman/8.0/en/identifier-case-sensitivity.html lower_case_table_names can only be configured when initializing the server.

You can do it using this script https://github.com/igrmk/ubuntu-reinit-mysql.

Please note that your data will be DESTROYED! So create a backup before running it.

Answer 2

Please go to below location and add the following code

location - cd /etc/mysql/mysql.conf.d/

then sudo vim mysqld.cnf

next, add below under the [mysqld]

lower_case_table_names=1

Answer 3

I also had the same issue.

I edited the /etc/mysql/conf.d/mysql.cnf file. (NOT the /etc/mysql/mysql.conf.d/mysqld.cnf file.)

I inset the lower_case_table_names=1 just below [mysqld] line. (There were no lines below [mysqld] line below.

Then I restarted mysql using sudo service mysql restart

It solved my issue.

Answer 4

This worked for me on a fresh Ubuntu Server 20.04 installation with MySQL 8.0.20 (no existing databases to care about - so if you have important data then you should backup/export it elsewhere before doing this):

So... I did everything with elevated permissions:

sudo su

Install MySQL (if not already installed):

apt-get install mysql-server

Backup configuration file, uninstall it, delete all databases and MySQL related data:

cp /etc/mysql/mysql.conf.d/mysqld.cnf /etc/mysql/mysql.conf.d/mysqld.cnf.backup
service mysql stop
apt-get --purge autoremove mysql-server
rm -R /var/lib/mysql

Restore saved configuration file, edit the file (add a line just under [mysqld] line):

cp /etc/mysql/mysql.conf.d/mysqld.cnf.backup /etc/mysql/mysql.conf.d/mysqld.cnf
vim /etc/mysql/mysql.conf.d/mysqld.cnf

...
lower_case_table_names=1
...

Reinstall MySQL (keeping the configuration file), configure additional settings:

apt-get install mysql-server
service mysql start
mysql_secure_installation
mysql

SHOW VARIABLES LIKE 'lower_case_%';
exit

Answer 5

In order to make this work in MySQL 8.0 and linux follow the steps bellow

0) Backup mysql schema before executing the following steps using

mysqldump  -h localhost -u root -p mysql > /home/username/dumps/mysqldump.sql

and then stop mysql using

sudo service mysql stop

1) move or remove /var/lib/mysql directory. This will delete all databases!!!!

mv /var/lib/mysql /tmp/mysql

2)Create a new /var/lib/mysql directory and make mysql user as owner

mkdir /var/lib/mysql
chown -R mysql:mysql /var/lib/mysql
chmod 750 /var/lib/mysql

3)edit /etc/mysql/mysql.conf.d/mysqld.cnf and add the following line after [mysqld]

lower_case_table_names=1

4) Initialize mysql using the following

mysqld --defaults-file=/etc/mysql/my.cnf --initialize lower_case_table_names=1 --user=mysql --console

Change defaults-file with the actual location of your defaults file. more info on mysql initialization here: https://dev.mysql.com/doc/refman/8.0/en/data-directory-initialization-mysqld.html

5) (Optional) Repeat

chown -R mysql:mysql /var/lib/mysql
chmod 750 /var/lib/mysql

if owner of the files in /var/lib/mysql is not mysql

6)Start mysql using

sudo service mysql start

7) If everything worked correctly, open mysql using

mysql -u root -p

and by running this query

SHOW VARIABLES where Variable_name like 'lower%';

you will get

'lower_case_table_names', '1'

8)Restore mysql schema using the dump created in step 0.

9)Execute mysql_upgrade to create the sys schema