You can add and delete users on the Virtual Appliance Management Interface to create the appropriate level of security:

Create a new user and add the user to the Virtual Appliance Management Interface group.
useradd -G vami,root

Create a password for the user.
passwd

Disable root access on the Virtual Appliance Management Interface.
usermod -R vami root

How to Verify that the password history enforced for the root account.
 cat /etc/pam.d/common-password-vmware.local | grep pam_pwhistory.so