MySQL root password unset

[Thirumalesh Gorantala]

Hi,

I have installed MySQL 5.1.73 version on CentOS 7. And after that reset root password using below commands

service mysql stop;mysqld_safe --skip-grant-tables &
mysql>
UPDATE mysql.user SET Password=PASSWORD('newpwd') WHERE User='root';
FLUSH PRIVILEGES;
exit;

mysqladmin -u root -p shutdown;service mysql start

But after every couple of hours this root pwd is getting unset and i can access DB using simple "mysql" command without using password

Does anyone faced this?

Thiru