To Delete MySQL bin-log files

Log files are in /var/lib/mysql/

root@server01 [~]# find /var/lib/mysql/ -name 'mysql-bin.*' | wc -l
21115
root@server01 [~]# find /var/lib/mysql/ -name 'mysql-bin.*' -exec rm -f {} \;
root@server01 [~]# find /var/lib/mysql/ -name 'mysql-bin.*' | wc -l
0

Mysql Downgrade in Cpanel server

We need to do the following steps for downgrade MySQL,

1. Change the MySQL version in /var/cpanel/cpanel.config file,

mysql-version=4.1 to mysql-version=4.0

2. Take old MySQL database bakup,

# cp -rpf /var/lib/mysql /var/lib/mysql.old

3. Remove the old database,

# rm -rf /var/lib/mysql

4. Remove old mysql binary,

# rm -f /usr/sbin/mysqld

5. Now run the script mysqlup

# /script/mysqlup --force

6. It will install MySQL 4.0 on server.