System Hostname

Why can i not use a FQDN with an existing DNS record outside my Cloudmin installation as a systems hostname?
All i get is this error:

Failed to create system : The hostname for a Xen instance cannot contain a . , as the domain name is added automatically

But i cant see no reason why i shouldnt use a FQDN for the guest.

Thanks for explaining that to me

When you create a Xen instance in Cloudmin, it expects you to just enter a name like “myvps” which is then used as the Xen instance name. The domain name that you set at Host Systems -> Xen Host Systems -> yourhost is then appended to get the fully qualified hostname.

Of course, once this is done you are free to register a DNS domain or add a DNS record separately like and have it resolve to the IP of your new Xen instance. You can then change the hostname in Cloudmin, on the Edit System page.

Thanks for explaining - but i still dont know why i cant use the FQDN straight away?
There must be a reason why i’m ‘forced’ to use a subdomain of my Host system.

The reason you can’t enter an arbitrary FQDN is that Cloudmin needs to create a DNS entry for that hostname to match the IP address it assigns for the Xen instance, and it can only do this for a hostname in the DNS domain that it controls.

I must admit, this baffled me at first too, but the more I use it, the more I think it’s not such a bad idea. I’ve had people come to me for a VPS before and had no idea what a hostname was or why they needed it and as such I had to manually provide them with one.