I'm currently configuring two-node HA cluster based on CentOS with DRBD.
Most services are packed in virtual machines with migration available.

I have not made decision where to put some core services as: dhcp, ldap, dns - which are critical for all network infrastructure.
There are two possibilities:

1. Configure them as redundant HA services on cluster hosts.
2. Pack them all into dedicated virtual machine.

What is the best practice?