You may see following error when you scanning ESXi hosts by vCenter Update Manager.
You also see similar logs in /var/log/esxupdate.log.
The root cause could be following:
Host cannot download files from VMware vSphere Update Manager patch store. Check the network connectivity and
firewall setup, and check esxupdate logs for details.
You also see similar logs in /var/log/esxupdate.log.
[Errno -2] Name or service not known
The root cause could be following:
- ESXi host cannot resolve DNS name of vCenter Update Manager Server.
- One of the DNS servers incorrect if you set multiple DNS servers on ESXi host.