Sometimes we need or want to have a DNS server for WHM cPanel for external synchronization/mirroring, without having to spend too much. By purchasing a cheap VPS of 512Mb of ram (minimum to have quality, experience of our own), we can circumvent the installation process by changing the minimum server requirements. Here are the steps:

1. Download installer: curl -the latest-dnsonly -L https://securedownloads.cpanel.net/latest-dnsonly
2. Start custom installation: sh latest-dnsonly --keep
3. Edit the installation file inside the created folder: vi /installd/install
4. Change the key below:
my $min_memory_rules = {
default => 512, # CentOS 5/6 => in a better world should be 512
7 => 1_024, #CentOS 7
};
5. Save the file and continue the installation: sh bootstrap-dnsonly