Error: An error occurred while connecting to depot during vLCM compliance check or vSphere HA configuration

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• vSphere HA configuration fails with the below error:
  
  Applying HA VIBs on the cluster encountered a failure". Failed installing HA component on the host
  
  
• Checking compliance on a cluster or a ESXi host fails with the below error:
  
  An error occurred while connecting to depot


• /var/run/log/lifecycle.log on ESXi host shows below entries:
  
  lifecycle[2110183]: imagemanagerctl:358 Got spec from vAPI: {'add_on': {'name': 'x86ArmPartcomponentaddon', 'version': '1.0.0-1'}, 'base_image': {'version': '<ESXi_version>'}, 'components': {}, 'hardware_support': None, 'solutions': None}
lifecycle[2110183]: Downloader:373 Opening http://<vCenter FQDN>:9084/vum/repository/hostupdate/__micro-depot__vendor-vmw__vmw-<ESXi_version>-metadata__index__.xml for download
lifecycle[2110183]: Downloader:210 Download failed: <urlopen error [Errno -2] Name or service not known>, 9 retry left...

Environment

• vCenter Server 7.0
• vCenter Server 8.0
• vSphere ESXi 7.0
• vSphere ESXi 8.0

Cause

This issue occurs when the ESXi host is unable to resolve the vCenter Server's FQDN or when network communication between the host and vCenter is blocked on TCP port 9084. To confirm this is the cause, log in to the affected ESXi host via SSH and perform the following:

1. Run the nc (netcat) utility to verify that TCP port 9084 is open and listening:

   nc -z <vCenter-FQDN-or-IP> 9084

   Success: Connection to <vCenter-IP-or-FQDN> 9084 port [tcp/*] succeeded!
Failure: nc: connect to <vCenter-IP-or-FQDN> port 9084 (tcp) failed: Connection refused or a timeout.

2. Attempt to download the metadata file over port 9084 using the wget command. Use the specific URL found in the ESXi host's lifecycle.log:
   
   wget http://<vCenter FQDN>:9084/vum/repository/hostupdate/__micro-depot__vendor-vmw__vmw-<ESXi_version>-metadata__index__.xml
   
   The command times out or fails to download the .xml file.
   
   Note: The above URL in the command will vary based on the specific environment

Resolution

1. Verify the ESXi host can successfully resolve the vCenter FQDN
2. Configure firewall rules to allow traffic from the ESXi host to vCenter over port 9084
3. Check the configuration of /etc/resolv.conf and /etc/hosts on the ESXi host to ensure proper name resolution.

Additional Information

Ensure this is not a match of "Download failed: <urlopen error timed out>", Enabling vSphere HA and vLCM Compliance check fails after upgrading vCenter Server to 8.0 U3 as this has a different cause and resolution.