My trusty single server is 5 years old with a single S2008r2 VM on ESXi with application services, file services, DNS, DHCP, and Active Directory Domain Services roles for 25 clients and 17 users in a medical office. We have backup covered, but want to add a new server and use replication for failover back to the old server. Both servers would be S2012r2 hyper-v hosts.
So my only domain controller has been virtual and we haven't had any problems, but I would like some advice for how to configure each Hyper-V host.
My research says the host should be off of the domain, have only the Hyper-V role enabled, and I will have a backup app there. I am guessing that I will need a VM for DNS, DHCP, and Active Directory Domain Services, and another for file and application services.
For my applications, I have a Sybase advantage database that gets the most users, and 3 sql server express databases. Should those be split into separate VMs so that sql server has it's own? Is it worth buying 2 extra 2012r2 licenses for the two hosts to have 3 VMs each now vs upgrading later if needed? Does it affect backup?
Appreciate your small business modified best practices advice.