VM not part of Domain after resize | Cloudbreak for Hortonworks Data Platform on Azure Marketplace

[#1]

Hello Team,
i have resized multiple VMs in my Azure HDP as per https://hortonworks.github.io/cloudbreak-azure-docs/azure-clusters-manage/index.html

after the resize one of the VMs is not resolving the FQDN and cant even resolve any DNS records 

while other VMs in the same Vnet/Subnet are working fine

any thoughts 

[#2]

Hello , 

We had the same problem upon resizing the machines via the azure portal.

Here are the steps to fix the issue :

1. netstat -tulpn | grep 53 - Ensure unbound resolver is running.
2. cat /var/lib/unbound/root.key - this file was empty which was the root cause of the issue.
3. "unbound-anchor -v" - execute this command to populate the root.key file
4. systemctl start unbound.service
5. systemctl status unbound.service
6. nslookup google.com