Why doesn't subdomain work in Apache 2?

Question

Uninterruptable power source

Hello! Created a configuration file /etc/apache2/sites-available/dfkids.ru.conf with the following content:

<VirtualHost *:80>
        ServerName dfkids.dart.fvds.ru
        ServerAlias *.dfkids.dart.fvds.ru
        ServerAdmin [email protected]
        DocumentRoot /var/www/dfkids
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

But for some reason the subdomain of my site does not open -
Cannot access the site
Cannot find the DNS address of the server dfkids.dart.fvds.ru.
ERR_NAME_NOT_RESOLVED
(the site itself looks like site1.host.com, the subdomain is sub1.site.host.com)
What could be the reason?
OS: Debian 8.5 Jessie

Answer 1

Thanks to. Here the question is immediately, but is there anything in the cheaper segments for my case, or are there exclusively top-end and expensive models?
For example, this model:
www.dns-shop.ru/product/817b6821c0a23361/ibp-apc-b...
Can it withstand the full power of this video card for at least a minute? (in case of power outage)

Answer 2

Why doesn't it open? Just a white page, error?
What's in the ${APACHE_LOG_DIR}/error.log and ${APACHE_LOG_DIR}/access.log logs when trying to open a page?