I had not given hostname or ip address during my initial installation of Redhat 9. MySQL was up and running and I was able to connect to MySQL instance after my Redhat 9 initial starting up, and even I startup OS many times later.
Then I use 'neat' command to change hostname and IP address and reboot my Redhat 9, the os up and running including MySQL DB. However, I got message of "Access denied for user: 'root@localhost' (Using password: NO)" when I tried to logon to MySQL instance by using user either 'mysql' or 'root'. Please anyone tell me how to fix it !! TKS, TKS.