This post is applicable to customers using VMware vCenter Server Appliance (vCSA) 6.7 Update 3d with vSphere Update Manager.

Problem:

1. vCenter Server Appliance 6.7 Update 3d with vSphere Update Manager configured to scan a cluster of ESXi hosts. DNS is fully configured and functioning correctly for ESXi and vCSA.
2. The Check Compliance action from the vSphere Client returns the error message: “There are errors during the scan operation. Check the events and log files for details.”
3. In the /var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server-log4cpp.log file of the vCSA instance, there are “HostUpdateDepotManager” ERROR messages with “http://<vcsa url>:9048/vum/repository/hostupdate/vmw/vmw-ESXi-6.7.0-metadata.zip – Name or service not known” listed.

Solution:

1. In the vSphere Client, select Home, Update Manager, Settings, Administration Settings, Network Connectivity.
2. Change the “Update Manager Patch Store host name or IP address” from the vCSA FQDN to the vCSA IP address from the drop-down menu.
3. The Check Compliance action should now complete successfully.
4. Try changing back to the vCSA FQDN to verify if Check Compliance still works.

Background:

I do not know why vUM behaves this way even though DNS is correctly configured, but the solution above is a workaround.