Host upgrade is failing with error 'Unable to download files'.

Products

• VMware vSphere ESXi

Issue/Introduction

• vCenter UI shows error 'Host cannot download files from VMware vSphere Lifecycle Manager patch store'.
  
  
  
  
• Host is unable to resolve fqdn of vCenter. Nslookup fails.
  [root@esx:~] nslookup <vCenter_URL>

Environment

VMware vSphere ESXi

Cause

Correct DNS server is not configured on host.

Resolution

Check DNS configuration on host.
[root@esx:~] cat /etc/hosts
[root@esx:~] cat /etc/resolv.conf

Add correct DNS server configuration on host and ensure it is able to resolve vCenter FQDN.

Additional Information

Refer to the following KB for steps to validate DNS configuration -
How to troubleshoot DNS and hostname resolution related issues

If the issue is still present refer to following KB for further troubleshooting steps -
"Host cannot download files from VMware vSphere Update Manager patch store. Check the network connectivity and firewall setup, and check esxupdate logs for details."