Removing MySQL completely on Linux

Question

I'm fairly new to Linux, when I first installed MySQL it was during an LAMP setup on personal machine with a Ubuntu Setup. ATM, I'm trying to get a fresh, clean install of only MySQL. I've been to trying to research how to fix this error:

  ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

But realized it's a wild goose-chase, this seems to be a common problem, with a number on solution of it not running in the background. Any Who, I still can't find out what my issue is and I know there is nothing important in this database, so:

 sudo apt-get purge mysql-server mysql-client

Or probably does work, but there is still (conf) files of it saved somewhere. What subdirectories/directories would I have to go into and do a 'sudo rm -f [db_files]' on. (Or other apt-get purge(s) am I missing)

Solution 1

What this error message says is "I am unable to connect throught a local file" which can mean either mysqld is not running or it is configured to disable socket or it is in another place.

To completly reinstall mysql :

1) Purge totally mysql packages : apt-get purge mysql mysql-server mysql-common mysql-client (depends on distributions). You can check for remaning packages with dpkg -l | grep mysql

2) Check that the configuration file is gone. It should be under /etc/my.cnf or /etc/mysql/my.cnf. You can make sure by doing find / -name my.cnf. (Note : anything under /usr/share are documentations and example configuration and should not make problems)

3) Remove or move the directory /var/lib/mysql which containe (old) database files

4) apt-get install mysql-server && /etc/init.d/mysqld start should get you a fresh new mysql install.

5) If the error remains, check that mysqld is running using command ps -ef | grep mysqld. If it is, you may want to specify the "sock" parameter under "[mysqld]" in the configuration file names in 2). You can also try to connect using mysql -h 127.0.0.1 --protocol=TCP to force a network connection instead of using UNIX sockets.

Solution 2

mysql removiing and reinstall process;

Step 1: Uninstall existing rpms using yum

# yum remove mysql mysql-server

Step 2: Remove or move /var/lib/mysql folder.

# mv /var/lib/mysql /var/lib/mysql-bak

Step 3: Reinstall mysql again using yum.

# yum install mysql mysql-server

Step 4: Now mysql service will start successfully.

Comments

[Tom]

Your error indicates that mysql was not running on the machine when you tried to connect to it, you could have tried running the server manually by running sudo /etc/init.d/mysqld. As for removing configuration files, apt-get purge should have done that, otherwise try sudo dpkg -P mysql-server or manually remove /etc/mysql/. As for database files, the default Ubuntu install location for them is, I want to say, /var/db, but I don't use Ubuntu so I don't know. Also, you might want to take this to askubuntu.com, which is the StackExchange site for Ubuntu users.

[Thalys]

from the use of apt, he's probably not on centos or RHEL - as they question says he runs ubuntu

[mveroone]

How did this question reached the top ? didn't see it was from a year ago. The problem is probably long gone...