Thanks for the method.
I also find it's okay if I set the DNS record of 'raw.githubusercontent.com' into /etc/hosts via terminal (if anyone wish not to stop the vm/docker is running
root@Server:~# head /etc/hosts
# Generated
127.0.0.1 Server localhost
54.149.176.35 keys.lime-technology.com
X.X.X.X raw.githubusercontent.com
replace the X.X.X.X part to the result of what nslookup raw.githubusercontent.com 8.8.8.8 told you
May I ask if you are running with any graphic cards with IPMI?
I currently have a 3600X + 1060 windows server and want to change to Unraid, I'm not sure if I can use IPMI to manage the server without graphic card with 3600X