Problem description
VMware backup proxy not visible or the status is disconnected on the Phoenix console: [Errno -2] Name or service not known.
Cause
Backup proxies with static IP addresses may experience this issue. When we see the error [Errno -2] Name or service not known, it is because the configuration details like DNS server and gateway given to the backup proxy are not working.
Traceback
Log location:
Telnet (
telnet phoenix.druva.com 443) from the backup proxy to check cloud connectivity returns the error"telnet: phoenix.druva.com: Name or service not known | phoenix.druva.com: Host name lookup failure".
Error in the main_service.log:
[2020-04-22 17:39:12,826] [ERROR] Error <class 'socket.gaierror'>:[Errno -3] Temporary failure in name resolution. Tracebackgaierror: [Errno-3] Temporary failure in name resolution.You may see the following error even when the connectivity between the backup proxy and cloud is fine.
Error in the main_service.log:
'datastore': '<datastore_Name>', 'network_name': 'VM Network'}
[2020-05-07 17:13:49,392] [ERROR] Error <class 'socket.gaierror'>:
[Errno -2] Name or service not known. Traceback -Traceback (most recent call last):
Resolution
Verify connectivity: Determine if the DNS server can be reached from the backup proxy by pinging it. This helps ensure there is a connection between the two.
Check IP address consistency: Confirm if the IP address of the DNS server has remained the same in your environment. Any changes should be noted and updated accordingly.
Review DNS address configuration: Take note of the DNS address entered during the backup proxy configuration. To access this information, shut down the backup proxy, navigate to the Configure Tab - Settings - vapp option (Right-hand side pane), and then network settings.
Examine static entries: Check for the presence of static entries on the DNS server. Static entries are manually configured and can potentially interfere with proper DNS resolution. Modify or remove any conflicting static entries as needed.
Consider network changes: If the previous steps haven't resolved the issue, contemplate making changes to the network configuration. This might involve examining network settings, IP configurations, or troubleshooting network connectivity between the backup proxy and the DNS server.
Ensure forward/reverse lookup is working to vCenter Server:
Use the nslookup command or equivalent tool to perform a forward and reverse lookup to the vCenter Server hostname or IP address.
If the lookup fails, check the DNS configuration, and resolve any issues.
Check resolv.conf and ensure DNS entry is correct:
Locate the resolv.conf file. The path for this file is typically /etc/resolv.conf on Linux
Open the file using a text editor.
Verify that the DNS entry in the resolv.conf file is correct, pointing to a valid DNS server.
If necessary, modify the resolv.conf file and update the DNS entry to the correct server.
Create host file entries of vCenter Server on VMware Backup Proxy:
Locate the host file on the VMware Backup Proxy machine. The path for the host file is typically /etc/hosts on Linux
Open the file using a text editor.
Add an entry for the vCenter Server in the host file, specifying the IP address and hostname of the vCenter Server.
Save the changes to the host file.
Here are some additional steps that can be taken to resolve the DNS resolution issue:
Whitelist '.druva.com': Make sure to include '.druva.com' in the whitelist. This ensures that any necessary DNS requests related to the '*.druva.com' domain are allowed.
Check the firewall for errors: Examine the firewall settings for any potential errors or misconfigurations that may be blocking DNS traffic. Correct any identified issues to ensure proper communication.
Verify the status of the Druva service: Check the status of the Druva service on the backup proxy. If the service is not running, start it using the following commands:
Execute '/etc/init.d/Phoenix status' to check the current status of the Druva service.
If the service is not running, execute '/etc/init.d/Phoenix start' to start the Druva service.
Review TCP packets using the Network Monitor tool: Capture and analyze TCP packets using the Network Monitor tool. Follow the instructions provided in the guide "How to setup and collect network capture using Network Monitor tool" to review the captured packets. This can help identify any network-level issues affecting DNS resolution.
Restart vCenter or backup proxy: As a final troubleshooting step, consider restarting the vCenter or backup proxy. Restarting these components can sometimes resolve underlying issues that may be impacting DNS resolution.