up all your mysql users, permissions, etc -- but it can wreak havoc with things like the debian-sys-m... word and the debian-sys-maint password, of course it won't automatically change the expected debian-sy... ld and new servers, you can use mysqladmin to fix it:
<code>mysql -p -u root password 'newpassword'</... However, when you apt-get installed mysql-server, it probably prompted you for the new mysql root pass