Update Manager scan fails with error: "An error occurred while scanning , check event logs for more details"

Products

• VMware vCenter Server

Issue/Introduction

• Update manger scan/stage fails with error: "An error occurred while scanning, check event logs for more details on all hosts"
• You will see similar log entries in vCenter Server logs as mentioned below.

 

/var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server-log4cpp.log 

[YYYY-MM-DDTHH:MM:SS] 'HostUpdateDepotManager' 140049206277888 ERROR]  [scanHost20, 371] result for host: <HOST FQDN> (entity: host-20) shows error :
-----Result Begin (<HOST FQDN>)-----
<esxupdate-response>
<version>1.50</version>
<error errorClass="MetadataDownloadError">
  <errorCode>4</errorCode>
  <errorDesc>Failed to download metadata.</errorDesc>
  <url>http://<HOST FQDN>:9084/vum/repository/hostupdate/Unknown/metadata-175.zip</url>
  <localfile>None</localfile>
  <msg>('http://<HOST FQDN>:9084/vum/repository/hostupdate/Unknown/metadata-175.zip', '/tmp/tmpvapusf93', '&lt;urlopen error [Errno -2] Name or service not known&gt;')</msg>
</error>
</esxupdate-response>

-----Result End (<HOST FQDN>)-----

Environment

VMware vCenter Server Appliance 6.7.x

Cause

The host is able to connect to the vCenter using the IP, but update manager is attempting to connect to the vCenter using the FQDN and unable to resolve.

Resolution

To resolve this issue:

1. Login into vCenter Server through SSH as Root and navigate to less /etc/hostname
2. The file contains the short name of the vCenter. Change it to fully qualified name.
3. Open SSH session to each host and edit the /etc/hosts file

4. For information on editing files using VI Editor, visit here. 
5. In this file add the following line:

<vCenter IP> <FQDN of vCenter> <vCenter short name>

6. After adding the line, /etc/hosts file should look like below.

 

# VAMI EDIT BEGIN
# Generated by Studio VAMI service. Do not modify manually.
127.0.0.1 <FQDN of vCenter> <vCenter short name> localhost
:: 1 <FQDN of vCenter> <vCenter short name> localhost ipv6-localhost ipv6-loopback
<vCenter IP> <FQDN of vCenter> <vCenter short name>
# VAMI EDIT END