A Case for a Physical DC at the DC
Today I was pulled into an interesting situation where a power outage knocked out a company's data center. The cascade started: UPSs had minimal uptime due to overloaded circuits, then full power outage. Everything. Power restored, everyone is scrambling, nothing works! Pull in the network dude. Queue Matthew West !
"Yo, it's me. I heard your DC went down. How about I put some DCs into your DC so you can DC with your DCs?"
As I started troubleshooting, I confirmed connectivity by IP out to the Internet, so it wasn't the 'network' per se. "But the internet isn't working!" Well, it is, but DNS isn't, so the World Wide Web is useless to you, I think. I say, "OK let's get DNS back up." "It's on the domain controllers which are on the virtual infrastructure... and it's where our monitoring is."
DNS is the most critical network service that many systems and network engineers overlook. Having all your domain controllers or DNS/DHCP servers virtualized increases your recovery time. Period.
Many forget that virtualization management platforms require DNS. Hosting your DNS servers there creates a barrier to bringing a company's full infrastructure back up. Here's my advice from a near 20-year veteran in IT Operations: Keep a domain controller at your DC physical, and while you are at it, you might want a PRTG or SolarWinds node physical for bonus points. Keep your heads up and your DCs!