1. Stop mysql service i.e.

/etc/init.d/ mysql stop

ps auxw|

grep -i mysql" command.

2. Find old installed rpms and remove –

rpm -qa | grep MySQL

remove old rpms

rpm -e --nodeps MySQL-xxx-xxxx MySQL-xxx XX XX

3. Safe copy of old mysql –

cd /var/lib/; cp -rp myql orig_mysql; mv mysql
mysql_5_0

4. install mysql-5.1
5. Stop mysql service –

/etc/init.d/ mysql stop

6. Cleanup directories from
orig_mysql –

cd /var/lib/orig_ mysql/; rm -rf
*.err *.pid plugins test mysql

7. Cleanup innodb files from newly installed mysql and move data from
orig_mysql to mysql –

cd /var/lib/mysql; rm -f ib*; mv ../orig_mysql/ * ./;
chown -R mysql:mysql *

9. Start mysql and run force upgrade-

/etc/init.d/ mysql start; mysql_upgrade
--force