I'm trying to get my head around how this aspect of my server works and am uncertain I'm understanding it correctly. I'm looking for either confirmation my assumptions below are correct or correction to the assumptions.
We have a dedicated server (running WHM & cPanel) which has multiple sites, including our own. We also have a couple of subdomains pointed to other servers and our email is hosted by a different service as well. Our NS records all point to our dedicated server. The setup is roughly as follows:
- site.com : our dedi server
- support.site.com : 3rd party service (zendesk)
- status.site.com : our dedi server (temporarily)
- emails / MX : 3rd party service (rackspace)
status.site.com is temporarily on our server, but I'm looking to move this to a separate server - I can't report downtime if status.site.com is down too!
We had some downtime recently due to a data center issue, and here's what happened when we did:
- site.com : down (obviously)
- support.site.com : accessible
- status.site.com : down
- emails : down
My assumptions then are as follows (please correct if I'm wrong!!):
- support.site.com has a CNAME record that points to the 3rd party server. Was this why subdomain was still accessible while the main server was down?
- email has the MX records set to point at the 3rd party service. Do the MX records work differently and have to buzz the server before bouncing on to the 3rd party service? Why is this different from how the subdomain worked?
Also, assuming I setup a separate server to host status.site.com, can I assume that this should then continue to function as support.site.com did in the event of server downtime?