IO is a often a bottleneck with databases and if your dedicated server has a second physical disk use that to improve IO throughput.
Here are the steps. Please note that these are steps for a CentOS 5.x system with /disk2 as the second HDD mount.
Step 1. Stop mysql
service mysqld stop
Step 2. locate my.cnf –To locate your mysql config file
Step 3. Open the file in your favourite browser like nano,pico or vi
Step 4. Look for the line for datadir. This is the current location of your mysql database files.
Step 5. Create a backup of your mysql folder
cp -R /var/lib/mysql /var/lib/mysql_backup
Step 6. Move mysql folder to /disk2
mv /var/lib/mysql /disk2/
Step 7. Change the ownership for the files to mysql
chown -R mysql.mysql /disk2/mysql
Step 8. Create a symbolic link from /var/lib/mysql to /disk2/mysql
ln -s /disk2/mysql/ /var/lib/mysql
Step 9. Edit the my.cnf file and modify the parameters as below
10. Start up mysql
service mysqld start
If, for any reason, mysqld fails to start check the log file
tail -10 /var/log/mysqld.log
If you need any help, please feel free to get in touch.