Cobra Forum

Question: Unable to start Apache on a Plesk server: Unable to find IPv4 address of server.example.com


Applicable to:

• Plesk for Linux

Symptoms

• Apache fails to start. One of the following error messages appears in the Apache error log file:

• on CentOS/RHEL-based distributions: /var/log/httpd/error_log

• on Debian/Ubuntu-based distributions: /var/log/apache2/error.log

(
EAI 2)Name or service not known: AH01564: unable to find IPv4 address of "server.example.com"
AH00016: Configuration Failed
(EAI 3)Temporary failure in name resolution: AH01564: unable to find IPv4 address of "ip-203-0-113-2"
AH00016: Configuration Failed


• The following email notification might be sent to Plesk administrator:

Unable to generate the web server configuration file on the host <server.example.com> because of the following errors: Template_Exception: Can not restart web server: file: /opt/psa/admin/plib/Service/Driver/Web/Server/Apache.php line: 109 code: 0
Unable to generate the web server configuration file on the host <server-hostname> because of the following errors:
Template_Exception: Can not restart web server: Apache is down, start it instead of graceful Apache is down, start it instead of graceful

Cause

There is no IPv4 address specified in the /etc/hosts file for the server name configured in /etc/hostname file.


Resolution

1.Log in to Plesk.

2.Go to Tools & Settings > Server Settings.

3.In the Full hostname field, set the server hostname.

4.Click OK.

5.Go to Tools & Settings > Services Management and make sure Web Server (Apache) is started.



                                        Command-line instructions


1.Connect to the Plesk server via SSH.

2.Open the file /etc/hosts in a text editor. In this example, we are using the vi editor:

# vi /etc/hosts

3.Add a valid <IPv4 hostname> configuration:, for example:

203.0.113.2 server.example.com


• Server hostname can be edited in the file /etc/hostname or can be found with the command hostname.

4.Reboot the server.

5.Verify that Apache has been started:

• on CentOS/RHEL-based distributions:

# service httpd status

• on Debian/Ubuntu-based distributions:

# service apache2 status