How to completely clean unistall MySql in Linux system redhat centos

Some time we faces issues with MySQL installation on Linux machine. If we simply remove MySQL packages and re-install doesn’t fixes the issue, in that case old settings may still exists on server which again affects new install. In that case first uninstall MySQL completely from system and erase all settings of old install. To do the same follow the below settings.

Note: Please do not use below steps if MySQL have any running databases.

First uninstall all the MySQL packages installed on your server

 # yum remove mysql mysql-server

Now we need to remove MySQL data directory from system which by default exists at /var/lib/mysql. If you didn’t find this, It may be changed to some other place, which you can find in my.cnf file with variable datadir. Delete the /var/lib/mysql directory from system but we prefer to rename it to keep a backup of existing files.

 # mv /var/lib/mysql /var/lib/mysql_old_backup

After removing MySQL completely, install it again using yum package manager, It will re create mysql directory under /var/lib/.

# mv /etc/my.cnf /etc/my.cnf_old_backup

# mv /etc/my.cnf.d /etc/my.cnf.d_old_backup

After completing above three steps, now you have a fresh MySQL install on your system with new settings.

After removing MySQL completely, install it again using yum package manager, It will re create mysql directory under /var/lib/ and mysql config under /etc/.

# yum install mysql mysql-server

After completing above three steps, now you have a fresh MySQL install on your system with new settings.